sock_unix(), which creates a listening Unix socket, doesn't set the SOCK_NONBLOCK flag. Generally, this doesn't matter because we only accept() once we've received an epoll event awaiting a connection. However we will need non-blocking accept() for the upcoming control/configuration socket. Always add SOCK_NONBLOCK, which is more robust and in keeping with the normal non-blocking style of passt. In tap.c, always set SOCK_NONBLOCK and SOCK_CLOEXEC on the accept()ed sockets as well, which we weren't doing in all cases before. According to accept(2), in Linux accepted sockets do *not* inherit these flags from the listening socket. Also check for failures of accept, discarding EAGAIN silently (a spurious epoll event) and warning for other errors. In repair.c, similarly always add CLOEXEC. Use NONBLOCK for discard sockets, but *not* for the final repair socket, since we want blocking transactions during migration. Signed-off-by: David Gibson --- repair.c | 9 +++++++-- tap.c | 12 ++++++++++-- util.c | 2 +- 3 files changed, 18 insertions(+), 5 deletions(-) diff --git a/repair.c b/repair.c index 69c53077..6c338da6 100644 --- a/repair.c +++ b/repair.c @@ -87,7 +87,7 @@ int repair_listen_handler(struct ctx *c, uint32_t events) /* Another client is already connected: accept and close right away. */ if (c->fd_repair != -1) { int discard = accept4(c->fd_repair_listen, NULL, NULL, - SOCK_NONBLOCK); + SOCK_CLOEXEC | SOCK_NONBLOCK); if (discard == -1) return errno; @@ -99,7 +99,12 @@ int repair_listen_handler(struct ctx *c, uint32_t events) return EEXIST; } - if ((c->fd_repair = accept4(c->fd_repair_listen, NULL, NULL, 0)) < 0) { + /* We deliberately *don't* set SOCK_NONBLOCK on the accepted socket, + * because repair transactions happen during migration, when everything + * is blocked anyway. + */ + if ((c->fd_repair = accept4(c->fd_repair_listen, NULL, NULL, + SOCK_CLOEXEC)) < 0) { rc = errno; debug_perror("accept4() on TCP_REPAIR helper listening socket"); return rc; diff --git a/tap.c b/tap.c index 7d06189d..87acd531 100644 --- a/tap.c +++ b/tap.c @@ -1415,7 +1415,7 @@ void tap_listen_handler(struct ctx *c, uint32_t events) /* Another client is already connected: accept and close right away. */ if (c->fd_tap != -1) { int discard = accept4(c->fd_tap_listen, NULL, NULL, - SOCK_NONBLOCK); + SOCK_NONBLOCK | SOCK_CLOEXEC); if (discard == -1) return; @@ -1428,7 +1428,15 @@ void tap_listen_handler(struct ctx *c, uint32_t events) return; } - c->fd_tap = accept4(c->fd_tap_listen, NULL, NULL, 0); + c->fd_tap = accept4(c->fd_tap_listen, NULL, NULL, + SOCK_NONBLOCK | SOCK_CLOEXEC); + if (c->fd_tap == -1) { + /* EAGAIN means a harmless spurious event */ + if (errno != EAGAIN) { + warn_perror("Unable to accept tap client"); + } + return; + } if (!getsockopt(c->fd_tap, SOL_SOCKET, SO_PEERCRED, &ucred, &len)) info("accepted connection from PID %i", ucred.pid); diff --git a/util.c b/util.c index 73c9d51d..204391c7 100644 --- a/util.c +++ b/util.c @@ -238,7 +238,7 @@ int sock_l4_dualstack_any(const struct ctx *c, enum epoll_type type, */ int sock_unix(char *sock_path) { - int fd = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0); + int fd = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0); struct sockaddr_un addr = { .sun_family = AF_UNIX, }; -- 2.53.0

In pesto we're going to want several levels of error/warning messages, much like passt itself. Particularly as we start to share mode code between passt and pesto, we want to use a similar interface to emit those. However we don't want to use the same implementation - logging to a file or syslog doesn't make sense for the command line tool. To accomplish this loosely share log.h, but not log.c between pesto and passt. In fact, an #ifdef means even most of log.h isn't actually shared, but we do provide similar warn(), die() etc. macros. This includes the *_perror() variants, which need strerror(). However, we want to avoid allocations for pesto as we do for passt, and strerror() allocates in some libc versions. Therefore, also move our workaround for this to be shared with pesto. Signed-off-by: Stefano Brivio [dwg: Based on changes part of a larger patch by Stefano] Signed-off-by: David Gibson --- Makefile | 6 +++++- common.h | 32 ++++++++++++++++++++++++++++++ log.h | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++++- pesto.c | 14 ++++---------- util.h | 32 ------------------------------ 5 files changed, 99 insertions(+), 44 deletions(-) diff --git a/Makefile b/Makefile index 030681b1..f6cec8a8 100644 --- a/Makefile +++ b/Makefile @@ -61,7 +61,7 @@ PASST_HEADERS = arch.h arp.h bitmap.h checksum.h common.h conf.h dhcp.h \ vhost_user.h virtio.h vu_common.h QRAP_HEADERS = arp.h ip.h passt.h util.h PASST_REPAIR_HEADERS = linux_dep.h -PESTO_HEADERS = common.h pesto.h +PESTO_HEADERS = common.h pesto.h log.h C := \#include \nint main(){int a=getrandom(0, 0, 0);} ifeq ($(shell printf "$(C)" | $(CC) -S -xc - -o - >/dev/null 2>&1; echo $$?),0) @@ -121,6 +121,7 @@ qrap: $(QRAP_SRCS) $(QRAP_HEADERS) passt-repair: $(PASST_REPAIR_SRCS) $(PASST_REPAIR_HEADERS) seccomp_repair.h +pesto: BASE_CPPFLAGS += -DPESTO pesto: $(PESTO_SRCS) $(PESTO_HEADERS) seccomp_pesto.h valgrind: EXTRA_SYSCALLS += rt_sigprocmask rt_sigtimedwait rt_sigaction \ @@ -221,9 +222,12 @@ cppcheck: passt.cppcheck passt-repair.cppcheck pesto.cppcheck qrap.cppcheck %.cppcheck: $(CPPCHECK) $(CPPCHECK_FLAGS) $(BASE_CPPFLAGS) $^ +passt.cppcheck: BASE_CPPFLAGS += -UPESTO passt.cppcheck: $(PASST_SRCS) $(PASST_HEADERS) seccomp.h + passt-repair.cppcheck: $(PASST_REPAIR_SRCS) $(PASST_REPAIR_HEADERS) seccomp_repair.h +pesto.cppcheck: BASE_CPPFLAGS += -DPESTO pesto.cppcheck: CPPCHECK_FLAGS += --suppress=unmatchedSuppression pesto.cppcheck: $(PESTO_SRCS) $(PESTO_HEADERS) seccomp_pesto.h diff --git a/common.h b/common.h index a9c115a5..2f2e6f1e 100644 --- a/common.h +++ b/common.h @@ -21,4 +21,36 @@ /* FPRINTF() intentionally silences cert-err33-c clang-tidy warnings */ #define FPRINTF(f, ...) (void)fprintf(f, __VA_ARGS__) +/* + * Starting from glibc 2.40.9000 and commit 25a5eb4010df ("string: strerror, + * strsignal cannot use buffer after dlmopen (bug 32026)"), strerror() needs + * getrandom(2) and brk(2) as it allocates memory for the locale-translated + * error description, but our seccomp profiles forbid both. + * + * Use the strerror_() wrapper instead, calling into strerrordesc_np() to get + * a static untranslated string. It's a GNU implementation, but also defined by + * bionic. + * + * If strerrordesc_np() is not defined (e.g. musl), call strerror(). C libraries + * not defining strerrordesc_np() are expected to provide strerror() + * implementations that are simple enough for us to call. + */ +__attribute__ ((weak)) const char *strerrordesc_np(int errnum); + +/** + * strerror_() - strerror() wrapper calling strerrordesc_np() if available + * @errnum: Error code + * + * Return: error description string + */ +static inline const char *strerror_(int errnum) +{ + if (strerrordesc_np) + return strerrordesc_np(errnum); + + return strerror(errnum); +} + +#define strerror(x) @ "Don't call strerror() directly, use strerror_() instead" + #endif /* _COMMON_H */ diff --git a/log.h b/log.h index dbab0067..1058ca5c 100644 --- a/log.h +++ b/log.h @@ -6,8 +6,63 @@ #ifndef LOG_H #define LOG_H -#include #include +#include +#include + +#ifdef PESTO + +#include + +#include "common.h" + +extern bool debug_flag; + +#define msg(...) \ + do { \ + FPRINTF(stderr, __VA_ARGS__); \ + FPRINTF(stderr, "\n"); \ + } while (0) + +#define msg_perror(...) \ + do { \ + int errno_ = errno; \ + FPRINTF(stderr, __VA_ARGS__); \ + FPRINTF(stderr, ": %s\n", strerror_(errno_)); \ + } while (0) + +#define die(...) \ + do { \ + msg(__VA_ARGS__); \ + exit(EXIT_FAILURE); \ + } while (0) + +#define die_perror(...) \ + do { \ + msg_perror(__VA_ARGS__); \ + exit(EXIT_FAILURE); \ + } while (0) + +#define warn(...) msg(__VA_ARGS__) +#define warn_perror(...) msg_perror(__VA_ARGS__) +#define info(...) msg(__VA_ARGS__) +#define info_perror(...) msg_perror(__VA_ARGS__) + +#define debug(...) \ + do { \ + if (debug_flag) \ + msg(__VA_ARGS__); \ + } while (0) + +#define debug_perror_(...) \ + do { \ + if (debug_flag) \ + msg_perror(__VA_ARGS__); \ + } while (0) + +#else /* !PESTO */ + +#include #include #include @@ -109,4 +164,6 @@ void __openlog(const char *ident, int option, int facility); void logfile_init(const char *name, const char *path, size_t size); void __setlogmask(int mask); +#endif /* !PESTO */ + #endif /* LOG_H */ diff --git a/pesto.c b/pesto.c index 9f2fa5d5..f0916e82 100644 --- a/pesto.c +++ b/pesto.c @@ -34,18 +34,12 @@ #include "common.h" #include "seccomp_pesto.h" #include "pesto.h" +#include "log.h" -static bool debug_flag = false; +bool debug_flag = false; static char stdout_buf[BUFSIZ]; -#define die(...) \ - do { \ - FPRINTF(stderr, __VA_ARGS__); \ - FPRINTF(stderr, "\n"); \ - exit(EXIT_FAILURE); \ - } while (0) - /** * usage() - Print usage, exit with given status code * @name: Executable name @@ -99,7 +93,7 @@ int main(int argc, char **argv) * breaking our seccomp profile. */ if (setvbuf(stdout, stdout_buf, _IOFBF, sizeof(stdout_buf))) - die("Failed to set stdout buffer"); + die_perror("Failed to set stdout buffer"); do { optname = getopt_long(argc, argv, optstring, options, NULL); @@ -126,7 +120,7 @@ int main(int argc, char **argv) if (argc - optind != 1) usage(argv[0], stderr, EXIT_FAILURE); - printf("debug_flag=%d, path=\"%s\"\n", debug_flag, argv[optind]); + debug("debug_flag=%d, path=\"%s\"", debug_flag, argv[optind]); die("pesto is not implemented yet"); } diff --git a/util.h b/util.h index 770ff93f..e90be47d 100644 --- a/util.h +++ b/util.h @@ -302,38 +302,6 @@ static inline bool mod_between(unsigned x, unsigned i, unsigned j, unsigned m) void raw_random(void *buf, size_t buflen); -/* - * Starting from glibc 2.40.9000 and commit 25a5eb4010df ("string: strerror, - * strsignal cannot use buffer after dlmopen (bug 32026)"), strerror() needs - * getrandom(2) and brk(2) as it allocates memory for the locale-translated - * error description, but our seccomp profiles forbid both. - * - * Use the strerror_() wrapper instead, calling into strerrordesc_np() to get - * a static untranslated string. It's a GNU implementation, but also defined by - * bionic. - * - * If strerrordesc_np() is not defined (e.g. musl), call strerror(). C libraries - * not defining strerrordesc_np() are expected to provide strerror() - * implementations that are simple enough for us to call. - */ -__attribute__ ((weak)) const char *strerrordesc_np(int errnum); - -/** - * strerror_() - strerror() wrapper calling strerrordesc_np() if available - * @errnum: Error code - * - * Return: error description string - */ -static inline const char *strerror_(int errnum) -{ - if (strerrordesc_np) - return strerrordesc_np(errnum); - - return strerror(errnum); -} - -#define strerror(x) @ "Don't call strerror() directly, use strerror_() instead" - /* * Workarounds for https://github.com/llvm/llvm-project/issues/58992 * -- 2.53.0

Start implementing pesto in earnest. Create a control/configuration socket in passt. Have pesto connect to it and retrieve a server greeting Perform some basic version checking. Signed-off-by: David Gibson --- Makefile | 8 ++- conf.c | 177 ++++++++++++++++++++++++++++++++++++++++++++++++++- conf.h | 2 + epoll_type.h | 4 ++ passt.1 | 5 ++ passt.c | 8 +++ passt.h | 6 ++ pesto.c | 47 +++++++++++++- pesto.h | 22 +++++++ serialise.c | 3 + 10 files changed, 276 insertions(+), 6 deletions(-) diff --git a/Makefile b/Makefile index f6cec8a8..1718ddbf 100644 --- a/Makefile +++ b/Makefile @@ -47,7 +47,7 @@ PASST_SRCS = arch.c arp.c bitmap.c checksum.c conf.c dhcp.c dhcpv6.c \ vhost_user.c virtio.c vu_common.c QRAP_SRCS = qrap.c PASST_REPAIR_SRCS = passt-repair.c -PESTO_SRCS = pesto.c +PESTO_SRCS = pesto.c serialise.c SRCS = $(PASST_SRCS) $(QRAP_SRCS) $(PASST_REPAIR_SRCS) $(PESTO_SRCS) MANPAGES = passt.1 pasta.1 pesto.1 qrap.1 passt-repair.1 @@ -61,7 +61,7 @@ PASST_HEADERS = arch.h arp.h bitmap.h checksum.h common.h conf.h dhcp.h \ vhost_user.h virtio.h vu_common.h QRAP_HEADERS = arp.h ip.h passt.h util.h PASST_REPAIR_HEADERS = linux_dep.h -PESTO_HEADERS = common.h pesto.h log.h +PESTO_HEADERS = common.h pesto.h log.h serialise.h C := \#include \nint main(){int a=getrandom(0, 0, 0);} ifeq ($(shell printf "$(C)" | $(CC) -S -xc - -o - >/dev/null 2>&1; echo $$?),0) @@ -228,7 +228,9 @@ passt.cppcheck: $(PASST_SRCS) $(PASST_HEADERS) seccomp.h passt-repair.cppcheck: $(PASST_REPAIR_SRCS) $(PASST_REPAIR_HEADERS) seccomp_repair.h pesto.cppcheck: BASE_CPPFLAGS += -DPESTO -pesto.cppcheck: CPPCHECK_FLAGS += --suppress=unmatchedSuppression +pesto.cppcheck: CPPCHECK_FLAGS += \ + --suppress=unusedFunction:serialise.c \ + --suppress=staticFunction:serialise.c pesto.cppcheck: $(PESTO_SRCS) $(PESTO_HEADERS) seccomp_pesto.h qrap.cppcheck: BASE_CPPFLAGS += -DARCH=\"$(TARGET_ARCH)\" diff --git a/conf.c b/conf.c index 05861072..fbf157fe 100644 --- a/conf.c +++ b/conf.c @@ -48,6 +48,10 @@ #include "isolation.h" #include "log.h" #include "vhost_user.h" +#include "epoll_ctl.h" +#include "conf.h" +#include "pesto.h" +#include "serialise.h" #define NETNS_RUN_DIR "/run/netns" @@ -541,6 +545,7 @@ static void usage(const char *name, FILE *f, int status) " --runas UID|UID:GID Run as given UID, GID, which can be\n" " numeric, or login and group names\n" " default: drop to user \"nobody\"\n" + " -c, --conf-path PATH Configuration socket path\n" " -h, --help Display this help message and exit\n" " --version Show version and exit\n"); @@ -779,6 +784,9 @@ static void conf_print(const struct ctx *c) char buf[INANY_ADDRSTRLEN]; int i; + if (c->fd_control_listen >= 0) + info("Configuration socket: %s", c->control_path); + if (c->ifi4 > 0 || c->ifi6 > 0) { char ifn[IFNAMSIZ]; @@ -1072,6 +1080,17 @@ static void conf_open_files(struct ctx *c) if (c->pidfile_fd < 0) die_perror("Couldn't open PID file %s", c->pidfile); } + + c->fd_control = -1; + if (*c->control_path) { + c->fd_control_listen = sock_unix(c->control_path); + if (c->fd_control_listen < 0) { + die_perror("Couldn't open control socket %s", + c->control_path); + } + } else { + c->fd_control_listen = -1; + } } /** @@ -1107,6 +1126,25 @@ fail: die("Invalid MAC address: %s", str); } +/** + * conf_sock_listen() - Start listening for connections on configuration socket + * @c: Execution context + */ +static void conf_sock_listen(const struct ctx *c) +{ + union epoll_ref ref = { .type = EPOLL_TYPE_CONF_LISTEN }; + + if (c->fd_control_listen < 0) + return; + + if (listen(c->fd_control_listen, 0)) + die_perror("Couldn't listen on configuration socket"); + + ref.fd = c->fd_control_listen; + if (epoll_add(c->epollfd, EPOLLIN | EPOLLET, ref)) + die_perror("Couldn't add configuration socket to epoll"); +} + /** * conf() - Process command-line arguments and set configuration * @c: Execution context @@ -1189,9 +1227,10 @@ void conf(struct ctx *c, int argc, char **argv) {"migrate-exit", no_argument, NULL, 29 }, {"migrate-no-linger", no_argument, NULL, 30 }, {"stats", required_argument, NULL, 31 }, + {"conf-path", required_argument, NULL, 'c' }, { 0 }, }; - const char *optstring = "+dqfel:hs:F:I:p:P:m:a:n:M:g:i:o:D:S:H:461t:u:T:U:"; + const char *optstring = "+dqfel:hs:c:F:I:p:P:m:a:n:M:g:i:o:D:S:H:461t:u:T:U:"; const char *logname = (c->mode == MODE_PASTA) ? "pasta" : "passt"; bool opt_t = false, opt_T = false, opt_u = false, opt_U = false; char userns[PATH_MAX] = { 0 }, netns[PATH_MAX] = { 0 }; @@ -1449,6 +1488,13 @@ void conf(struct ctx *c, int argc, char **argv) c->fd_tap = -1; break; + case 'c': + ret = snprintf(c->control_path, sizeof(c->control_path), + "%s", optarg); + if (ret <= 0 || ret >= (int)sizeof(c->sock_path)) + die("Invalid configuration path: %s", optarg); + c->fd_control_listen = c->fd_control = -1; + break; case 'F': errno = 0; fd_tap_opt = strtol(optarg, NULL, 0); @@ -1871,6 +1917,135 @@ void conf(struct ctx *c, int argc, char **argv) fwd_rule_parse('U', "auto", c->fwd[PIF_SPLICE]); } + conf_sock_listen(c); + if (!c->quiet) conf_print(c); } + +static void conf_accept(struct ctx *c); + +/** + * conf_close() - Close configuration / control socket and clean up + * @c: Execution context + */ +static void conf_close(struct ctx *c) +{ + debug("Closing configuration socket"); + epoll_ctl(c->epollfd, EPOLL_CTL_DEL, c->fd_control, NULL); + close(c->fd_control); + c->fd_control = -1; + + /* Check if any other clients are waiting to connect */ + conf_accept(c); +} + +/** + * conf_listen_handler() - Handle events on configuration listening socket + * @c: Execution context + * @events: epoll events + */ +void conf_listen_handler(struct ctx *c, uint32_t events) +{ + if (events != EPOLLIN) { + err("Unexpected event 0x%04x on configuration socket", events); + return; + } + + if (c->fd_control >= 0) { + /* Ignore the new connection for now, blocking it until the + * current one finishes. + */ + return; + } + + conf_accept(c); +} + +/** + * conf_accept() - Accept a new control connection + * @c: Execution context + */ +static void conf_accept(struct ctx *c) +{ + struct pesto_hello hello = { + .magic = PESTO_SERVER_MAGIC, + .version = htonl(PESTO_PROTOCOL_VERSION), + }; + union epoll_ref ref = { .type = EPOLL_TYPE_CONF }; + struct ucred uc = { 0 }; + socklen_t len = sizeof(uc); + int fd, rc; + + fd = accept4(c->fd_control_listen, NULL, NULL, + SOCK_NONBLOCK | SOCK_CLOEXEC); + if (fd < 0) { + if (errno != EAGAIN) + warn_perror("accept4() on configuration listening socket"); + return; + } + + if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &uc, &len) < 0) + warn_perror("Can't get configuration client credentials"); + + c->fd_control = ref.fd = fd; + rc = epoll_add(c->epollfd, EPOLLIN | EPOLLET, ref); + if (rc < 0) { + warn_perror("epoll_ctl() on configuration socket"); + goto fail; + } + + rc = write_all_buf(fd, &hello, sizeof(hello)); + if (rc < 0) { + warn_perror("Error writing configuration protocol hello"); + goto fail; + } + + info("Accepted configuration client, PID %i", uc.pid); + if (!PESTO_PROTOCOL_VERSION) { + warn( +"Warning: Using experimental unsupported configuration protocol"); + } + + return; + +fail: + conf_close(c); +} + +/** + * conf_handler() - Handle events on configuration socket + * @c: Execution context + * @events: epoll events + */ +void conf_handler(struct ctx *c, uint32_t events) +{ + if (events & EPOLLIN) { + char discard[BUFSIZ]; + ssize_t n; + + do { + n = read(c->fd_control, discard, sizeof(discard)); + if (n > 0) + debug("Discarded %zd bytes of config data", n); + } while (n > 0); + if (n == 0) { + debug("Configuration client EOF"); + goto close; + } + if (errno != EAGAIN && errno != EWOULDBLOCK) { + err_perror("Error reading config data"); + goto close; + } + } + + if (events & EPOLLHUP) { + debug("Configuration client hangup"); + goto close; + } + + return; + +close: + conf_close(c); +} diff --git a/conf.h b/conf.h index b45ad746..16f97189 100644 --- a/conf.h +++ b/conf.h @@ -8,5 +8,7 @@ enum passt_modes conf_mode(int argc, char *argv[]); void conf(struct ctx *c, int argc, char **argv); +void conf_listen_handler(struct ctx *c, uint32_t events); +void conf_handler(struct ctx *c, uint32_t events); #endif /* CONF_H */ diff --git a/epoll_type.h b/epoll_type.h index a90ffb67..061325aa 100644 --- a/epoll_type.h +++ b/epoll_type.h @@ -46,6 +46,10 @@ enum epoll_type { EPOLL_TYPE_REPAIR, /* Netlink neighbour subscription socket */ EPOLL_TYPE_NL_NEIGH, + /* Configuration listening socket */ + EPOLL_TYPE_CONF_LISTEN, + /* Configuration socket */ + EPOLL_TYPE_CONF, EPOLL_NUM_TYPES, }; diff --git a/passt.1 b/passt.1 index 6303aeb0..908fd4a4 100644 --- a/passt.1 +++ b/passt.1 @@ -127,6 +127,11 @@ login name and group name can be passed. This requires privileges (either initial effective UID 0 or CAP_SETUID capability) to work. Default is to change to user \fInobody\fR if started as root. +.TP +.BR \-c ", " \-\-conf-path " " \fIpath " " (EXPERIMENTAL) +Path for configuration and control socket used by \fBpesto\fR(1) to +dynamically update passt or pasta's configuration. + .TP .BR \-h ", " \-\-help Display a help message and exit. diff --git a/passt.c b/passt.c index f84419c7..bc42ea33 100644 --- a/passt.c +++ b/passt.c @@ -80,6 +80,8 @@ char *epoll_type_str[] = { [EPOLL_TYPE_REPAIR_LISTEN] = "TCP_REPAIR helper listening socket", [EPOLL_TYPE_REPAIR] = "TCP_REPAIR helper socket", [EPOLL_TYPE_NL_NEIGH] = "netlink neighbour notifier socket", + [EPOLL_TYPE_CONF_LISTEN] = "configuration listening socket", + [EPOLL_TYPE_CONF] = "configuration socket", }; static_assert(ARRAY_SIZE(epoll_type_str) == EPOLL_NUM_TYPES, "epoll_type_str[] doesn't match enum epoll_type"); @@ -303,6 +305,12 @@ static void passt_worker(void *opaque, int nfds, struct epoll_event *events) case EPOLL_TYPE_NL_NEIGH: nl_neigh_notify_handler(c); break; + case EPOLL_TYPE_CONF_LISTEN: + conf_listen_handler(c, eventmask); + break; + case EPOLL_TYPE_CONF: + conf_handler(c, eventmask); + break; default: /* Can't happen */ assert(0); diff --git a/passt.h b/passt.h index 62b8dcdf..b3f049de 100644 --- a/passt.h +++ b/passt.h @@ -158,6 +158,7 @@ struct ip6_ctx { * @foreground: Run in foreground, don't log to stderr by default * @nofile: Maximum number of open files (ulimit -n) * @sock_path: Path for UNIX domain socket + * @control_path: Path for control/configuration UNIX domain socket * @repair_path: TCP_REPAIR helper path, can be "none", empty for default * @pcap: Path for packet capture file * @pidfile: Path to PID file, empty string if not configured @@ -169,6 +170,8 @@ struct ip6_ctx { * @epollfd: File descriptor for epoll instance * @fd_tap_listen: File descriptor for listening AF_UNIX socket, if any * @fd_tap: AF_UNIX socket, tuntap device, or pre-opened socket + * @fd_control_listen: Listening control/configuration socket, if any + * @fd_control: Control/configuration socket, if any * @fd_repair_listen: File descriptor for listening TCP_REPAIR socket, if any * @fd_repair: Connected AF_UNIX socket for TCP_REPAIR helper * @our_tap_mac: Pasta/passt's MAC on the tap link @@ -223,6 +226,7 @@ struct ctx { int foreground; int nofile; char sock_path[UNIX_PATH_MAX]; + char control_path[UNIX_PATH_MAX]; char repair_path[UNIX_PATH_MAX]; char pcap[PATH_MAX]; @@ -240,6 +244,8 @@ struct ctx { int epollfd; int fd_tap_listen; int fd_tap; + int fd_control_listen; + int fd_control; int fd_repair_listen; int fd_repair; unsigned char our_tap_mac[ETH_ALEN]; diff --git a/pesto.c b/pesto.c index f0916e82..5e191283 100644 --- a/pesto.c +++ b/pesto.c @@ -33,6 +33,7 @@ #include "common.h" #include "seccomp_pesto.h" +#include "serialise.h" #include "pesto.h" #include "log.h" @@ -66,6 +67,8 @@ static void usage(const char *name, FILE *f, int status) * * Return: 0 on success, won't return on failure * + * #syscalls:pesto socket s390x:socketcall i686:socketcall + * #syscalls:pesto connect shutdown close * #syscalls:pesto exit_group fstat read write */ int main(int argc, char **argv) @@ -76,9 +79,12 @@ int main(int argc, char **argv) {"version", no_argument, NULL, 1 }, { 0 }, }; + struct sockaddr_un a = { AF_UNIX, "" }; const char *optstring = "dh"; + struct pesto_hello hello; struct sock_fprog prog; - int optname; + int optname, ret, s; + uint32_t s_version; prctl(PR_SET_DUMPABLE, 0); @@ -122,5 +128,42 @@ int main(int argc, char **argv) debug("debug_flag=%d, path=\"%s\"", debug_flag, argv[optind]); - die("pesto is not implemented yet"); + if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) + die_perror("Failed to create AF_UNIX socket"); + + ret = snprintf(a.sun_path, sizeof(a.sun_path), "%s", argv[optind]); + if (ret <= 0 || ret >= (int)sizeof(a.sun_path)) + die("Invalid socket path \"%s\"", argv[1]); + + ret = connect(s, (struct sockaddr *)&a, sizeof(a)); + if (ret < 0) { + die_perror("Failed to connect to %s", a.sun_path); + } + + ret = read_all_buf(s, &hello, sizeof(hello)); + if (ret < 0) + die_perror("Couldn't read server greeting"); + + if (memcmp(hello.magic, PESTO_SERVER_MAGIC, sizeof(hello.magic))) + die("Bad magic number from server"); + + s_version = ntohl(hello.version); + + if (s_version > PESTO_PROTOCOL_VERSION) { + die("Unknown server protocol version %"PRIu32" > %"PRIu32"\n", + s_version, PESTO_PROTOCOL_VERSION); + } + + /* cppcheck-suppress knownConditionTrueFalse */ + if (!s_version) { + if (PESTO_PROTOCOL_VERSION) + die("Unsupported experimental server protocol"); + FPRINTF(stderr, +"Warning: Using experimental protocol version, client and server must match\n"); + } + + if (shutdown(s, SHUT_RDWR) < 0 || close(s) < 0) + die_perror("Error shutting down control socket"); + + exit(0); } diff --git a/pesto.h b/pesto.h index e9b329f4..92d4df3a 100644 --- a/pesto.h +++ b/pesto.h @@ -9,4 +9,26 @@ #ifndef PESTO_H #define PESTO_H +#include +#include + +#define PESTO_SERVER_MAGIC "pesto:s" + +/* Version 0 is reserved for unreleased / unsupported experimental versions */ +#define PESTO_PROTOCOL_VERSION 0 + +/** + * struct pesto_hello - Server introduction message + * @magic: PESTO_SERVER_MAGIC + * @version: Version number + */ +struct pesto_hello { + char magic[8]; + uint32_t version; +} __attribute__ ((__packed__)); + +static_assert(sizeof(PESTO_SERVER_MAGIC) + == sizeof(((struct pesto_hello *)0)->magic), + "PESTO_SERVER_MAGIC has wrong size"); + #endif /* PESTO_H */ diff --git a/serialise.c b/serialise.c index 944e7414..346df998 100644 --- a/serialise.c +++ b/serialise.c @@ -6,6 +6,9 @@ * PASTA - Pack A Subtle Tap Abstraction * for network namespace/tap device mode * + * PESTO - Programmable Extensible Socket Translation Orchestrator + * front-end for passt(1) and pasta(1) forwarding configuration + * * serialise.c - Serialisation of data structures over bytestreams * * Copyright Red Hat -- 2.53.0

Build a new "pesto" binary, which will become the tool to update a running passt/pasta's configuration. For now, we just build a stub binary which sets up a basic environment, parses trivial command line options but does nothing else. Signed-off-by: David Gibson --- .gitignore | 2 + Makefile | 42 +++++++++++------ common.h | 24 ++++++++++ pesto.1 | 46 +++++++++++++++++++ pesto.c | 132 +++++++++++++++++++++++++++++++++++++++++++++++++++++ pesto.h | 12 +++++ util.h | 12 +---- 7 files changed, 244 insertions(+), 26 deletions(-) create mode 100644 common.h create mode 100644 pesto.1 create mode 100644 pesto.c create mode 100644 pesto.h diff --git a/.gitignore b/.gitignore index 3c16adc7..3e40d9f7 100644 --- a/.gitignore +++ b/.gitignore @@ -4,9 +4,11 @@ /pasta /pasta.avx2 /passt-repair +/pesto /qrap /pasta.1 /seccomp.h +/seccomp_pesto.h /seccomp_repair.h /c*.json README.plain.md diff --git a/Makefile b/Makefile index 7875d23b..030681b1 100644 --- a/Makefile +++ b/Makefile @@ -47,19 +47,21 @@ PASST_SRCS = arch.c arp.c bitmap.c checksum.c conf.c dhcp.c dhcpv6.c \ vhost_user.c virtio.c vu_common.c QRAP_SRCS = qrap.c PASST_REPAIR_SRCS = passt-repair.c -SRCS = $(PASST_SRCS) $(QRAP_SRCS) $(PASST_REPAIR_SRCS) - -MANPAGES = passt.1 pasta.1 qrap.1 passt-repair.1 - -PASST_HEADERS = arch.h arp.h bitmap.h checksum.h conf.h dhcp.h dhcpv6.h \ - epoll_ctl.h flow.h fwd.h fwd_rule.h flow_table.h icmp.h icmp_flow.h \ - inany.h iov.h ip.h isolation.h lineread.h log.h migrate.h ndp.h \ - netlink.h packet.h passt.h pasta.h pcap.h pif.h repair.h serialise.h \ - siphash.h tap.h tcp.h tcp_buf.h tcp_conn.h tcp_internal.h tcp_splice.h \ - tcp_vu.h udp.h udp_flow.h udp_internal.h udp_vu.h util.h vhost_user.h \ - virtio.h vu_common.h +PESTO_SRCS = pesto.c +SRCS = $(PASST_SRCS) $(QRAP_SRCS) $(PASST_REPAIR_SRCS) $(PESTO_SRCS) + +MANPAGES = passt.1 pasta.1 pesto.1 qrap.1 passt-repair.1 + +PASST_HEADERS = arch.h arp.h bitmap.h checksum.h common.h conf.h dhcp.h \ + dhcpv6.h epoll_ctl.h flow.h fwd.h fwd_rule.h flow_table.h icmp.h \ + icmp_flow.h inany.h iov.h ip.h isolation.h lineread.h log.h migrate.h \ + ndp.h netlink.h packet.h passt.h pasta.h pcap.h pesto.h pif.h repair.h \ + serialise.h siphash.h tap.h tcp.h tcp_buf.h tcp_conn.h tcp_internal.h \ + tcp_splice.h tcp_vu.h udp.h udp_flow.h udp_internal.h udp_vu.h util.h \ + vhost_user.h virtio.h vu_common.h QRAP_HEADERS = arp.h ip.h passt.h util.h PASST_REPAIR_HEADERS = linux_dep.h +PESTO_HEADERS = common.h pesto.h C := \#include \nint main(){int a=getrandom(0, 0, 0);} ifeq ($(shell printf "$(C)" | $(CC) -S -xc - -o - >/dev/null 2>&1; echo $$?),0) @@ -78,7 +80,7 @@ docdir ?= $(datarootdir)/doc/passt mandir ?= $(datarootdir)/man man1dir ?= $(mandir)/man1 -BASEBIN = passt qrap passt-repair +BASEBIN = passt qrap passt-repair pesto ifeq ($(TARGET_ARCH),x86_64) BASEBIN += passt.avx2 endif @@ -100,6 +102,9 @@ seccomp.h: seccomp.sh $(PASST_SRCS) $(PASST_HEADERS) seccomp_repair.h: seccomp.sh $(PASST_REPAIR_SRCS) $(PASST_REPAIR_HEADERS) @ ARCH="$(TARGET_ARCH)" CC="$(CC)" ./seccomp.sh seccomp_repair.h $(PASST_REPAIR_SRCS) +seccomp_pesto.h: seccomp.sh $(PESTO_SRCS) + @ ARCH="$(TARGET_ARCH)" CC="$(CC)" ./seccomp.sh seccomp_pesto.h $(PESTO_SRCS) + $(BASEBIN): %: $(CC) $(BASE_CPPFLAGS) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) $(filter %.c,$^) -o $@ @@ -116,6 +121,8 @@ qrap: $(QRAP_SRCS) $(QRAP_HEADERS) passt-repair: $(PASST_REPAIR_SRCS) $(PASST_REPAIR_HEADERS) seccomp_repair.h +pesto: $(PESTO_SRCS) $(PESTO_HEADERS) seccomp_pesto.h + valgrind: EXTRA_SYSCALLS += rt_sigprocmask rt_sigtimedwait rt_sigaction \ rt_sigreturn getpid gettid kill clock_gettime \ mmap|mmap2 munmap open unlink gettimeofday futex \ @@ -126,7 +133,7 @@ valgrind: all .PHONY: clean clean: - $(RM) $(BIN) *~ *.o seccomp.h seccomp_repair.h pasta.1 \ + $(RM) $(BIN) *~ *.o seccomp.h seccomp_repair.h seccomp_pesto.h pasta.1 \ passt.tar passt.tar.gz *.deb *.rpm \ passt.pid README.plain.md @@ -183,7 +190,8 @@ docs: README.md CLANG_TIDY = clang-tidy CLANG_TIDY_FLAGS = -DCLANG_TIDY_58992 -clang-tidy: passt.clang-tidy passt-repair.clang-tidy qrap.clang-tidy +clang-tidy: passt.clang-tidy passt-repair.clang-tidy pesto.clang-tidy \ + qrap.clang-tidy .PHONY: %.clang-tidy %.clang-tidy: @@ -191,6 +199,7 @@ clang-tidy: passt.clang-tidy passt-repair.clang-tidy qrap.clang-tidy passt.clang-tidy: $(PASST_SRCS) $(PASST_HEADERS) seccomp.h passt-repair.clang-tidy: $(PASST_REPAIR_SRCS) $(PASST_REPAIR_HEADERS) seccomp_repair.h +pesto.clang-tidy: $(PESTO_SRCS) $(PESTO_HEADERS) seccomp_pesto.h qrap.clang-tidy: $(QRAP_SRCS) $(QRAP_HEADERS) CPPCHECK = cppcheck @@ -206,7 +215,7 @@ CPPCHECK_FLAGS = --std=c11 --error-exitcode=1 --enable=all --force \ --suppress=unusedStructMember \ -D CPPCHECK_6936 -cppcheck: passt.cppcheck passt-repair.cppcheck qrap.cppcheck +cppcheck: passt.cppcheck passt-repair.cppcheck pesto.cppcheck qrap.cppcheck .PHONY: %.cppcheck %.cppcheck: @@ -215,6 +224,9 @@ cppcheck: passt.cppcheck passt-repair.cppcheck qrap.cppcheck passt.cppcheck: $(PASST_SRCS) $(PASST_HEADERS) seccomp.h passt-repair.cppcheck: $(PASST_REPAIR_SRCS) $(PASST_REPAIR_HEADERS) seccomp_repair.h +pesto.cppcheck: CPPCHECK_FLAGS += --suppress=unmatchedSuppression +pesto.cppcheck: $(PESTO_SRCS) $(PESTO_HEADERS) seccomp_pesto.h + qrap.cppcheck: BASE_CPPFLAGS += -DARCH=\"$(TARGET_ARCH)\" qrap.cppcheck: CPPCHECK_FLAGS += --suppress=unusedFunction qrap.cppcheck: $(QRAP_SRCS) $(QRAP_HEADERS) diff --git a/common.h b/common.h new file mode 100644 index 00000000..a9c115a5 --- /dev/null +++ b/common.h @@ -0,0 +1,24 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later + * Copyright Red Hat + * Author: David Gibson + * + * Definitions used by both passt/pasta and other tools + */ + +#ifndef COMMON_H +#define COMMON_H + +#include + +#define VERSION_BLOB \ + VERSION "\n" \ + "Copyright Red Hat\n" \ + "GNU General Public License, version 2 or later\n" \ + " https://www.gnu.org/licenses/old-licenses/gpl-2.0.html\n" \ + "This is free software: you are free to change and redistribute it.\n" \ + "There is NO WARRANTY, to the extent permitted by law.\n\n" + +/* FPRINTF() intentionally silences cert-err33-c clang-tidy warnings */ +#define FPRINTF(f, ...) (void)fprintf(f, __VA_ARGS__) + +#endif /* _COMMON_H */ diff --git a/pesto.1 b/pesto.1 new file mode 100644 index 00000000..338fb8a6 --- /dev/null +++ b/pesto.1 @@ -0,0 +1,46 @@ +.\" SPDX-License-Identifier: GPL-2.0-or-later +.\" Copyright Red Hat +.\" Author: David Gibson +.TH pesto 1 + +.SH NAME +.B pesto +\- Configure a running \fBpasst\fR(1) or \fBpasta\fR(1) instance. + +.SH SYNOPSIS +.B pesto +\fIPATH\fR + +.SH DESCRIPTION + +.B pesto +is an experimental client to view and update the port forwarding +configuration of a running \fBpasst\fR(1) or \fBpasta\fR(1) instance. + +\fIPATH\fR gives the path to the UNIX domain socket created by +\fBpasst\fR or \fBpasta\fR. It should match the \fB-c\fR command line +option given to that instance. + +.SH AUTHORS + +Stefano Brivio , +David Gibson . + +.SH REPORTING BUGS + +Please report issues on the bug tracker at https://bugs.passt.top/, or +send a message to the passt-user@passt.top mailing list, see +https://lists.passt.top/. + +.SH COPYRIGHT + +Copyright Red Hat + +\fBpesto\fR is free software: you can redistribute them and/or modify +them under the terms of the GNU General Public License as published by +the Free Software Foundation, either version 2 of the License, or (at +your option) any later version. + +.SH SEE ALSO + +\fBpasst\fR(1), \fBpasta\fR(1), \fBunix\fR(7). diff --git a/pesto.c b/pesto.c new file mode 100644 index 00000000..9f2fa5d5 --- /dev/null +++ b/pesto.c @@ -0,0 +1,132 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +/* PESTO - Programmable Extensible Socket Translation Orchestrator + * front-end for passt(1) and pasta(1) forwarding configuration + * + * pesto.c - Main program (it's not actually extensible) + * + * Copyright (c) 2026 Red Hat GmbH + * Author: Stefano Brivio + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +#include "common.h" +#include "seccomp_pesto.h" +#include "pesto.h" + +static bool debug_flag = false; + +static char stdout_buf[BUFSIZ]; + +#define die(...) \ + do { \ + FPRINTF(stderr, __VA_ARGS__); \ + FPRINTF(stderr, "\n"); \ + exit(EXIT_FAILURE); \ + } while (0) + +/** + * usage() - Print usage, exit with given status code + * @name: Executable name + * @f: Stream to print usage info to + * @status: Status code for exit(2) + * + * #syscalls:pesto exit_group fstat write + */ +static void usage(const char *name, FILE *f, int status) +{ + FPRINTF(f, "Usage: %s [OPTION]... PATH\n", name); + FPRINTF(f, + "\n" + " -d, --debug Print debugging messages\n" + " -h, --help Display this help message and exit\n" + " --version Show version and exit\n"); + exit(status); +} + +/** + * main() - Dynamic reconfiguration client main program + * @argc: Argument count + * @argv: Arguments: socket path, operation, port specifiers + * + * Return: 0 on success, won't return on failure + * + * #syscalls:pesto exit_group fstat read write + */ +int main(int argc, char **argv) +{ + const struct option options[] = { + {"debug", no_argument, NULL, 'd' }, + {"help", no_argument, NULL, 'h' }, + {"version", no_argument, NULL, 1 }, + { 0 }, + }; + const char *optstring = "dh"; + struct sock_fprog prog; + int optname; + + prctl(PR_SET_DUMPABLE, 0); + + prog.len = (unsigned short)sizeof(filter_pesto) / + sizeof(filter_pesto[0]); + prog.filter = filter_pesto; + if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) || + prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog)) + die("Failed to apply seccomp filter"); + + /* Explicitly set stdout buffer, otherwise printf() might allocate, + * breaking our seccomp profile. + */ + if (setvbuf(stdout, stdout_buf, _IOFBF, sizeof(stdout_buf))) + die("Failed to set stdout buffer"); + + do { + optname = getopt_long(argc, argv, optstring, options, NULL); + + switch (optname) { + case -1: + case 0: + break; + case 'h': + usage(argv[0], stdout, EXIT_SUCCESS); + break; + case 'd': + debug_flag = true; + break; + case 1: + FPRINTF(stdout, "pesto "); + FPRINTF(stdout, VERSION_BLOB); + exit(EXIT_SUCCESS); + default: + usage(argv[0], stderr, EXIT_FAILURE); + } + } while (optname != -1); + + if (argc - optind != 1) + usage(argv[0], stderr, EXIT_FAILURE); + + printf("debug_flag=%d, path=\"%s\"\n", debug_flag, argv[optind]); + + die("pesto is not implemented yet"); +} diff --git a/pesto.h b/pesto.h new file mode 100644 index 00000000..e9b329f4 --- /dev/null +++ b/pesto.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later + * Copyright Red Hat + * Author: David Gibson + * + * Definitions and functions used by both client and server of the configuration + * update protocol (pesto). + */ + +#ifndef PESTO_H +#define PESTO_H + +#endif /* PESTO_H */ diff --git a/util.h b/util.h index 92aeabc8..770ff93f 100644 --- a/util.h +++ b/util.h @@ -19,16 +19,9 @@ #include #include +#include "common.h" #include "log.h" -#define VERSION_BLOB \ - VERSION "\n" \ - "Copyright Red Hat\n" \ - "GNU General Public License, version 2 or later\n" \ - " https://www.gnu.org/licenses/old-licenses/gpl-2.0.html\n" \ - "This is free software: you are free to change and redistribute it.\n" \ - "There is NO WARRANTY, to the extent permitted by law.\n\n" - #ifndef SECCOMP_RET_KILL_PROCESS #define SECCOMP_RET_KILL_PROCESS SECCOMP_RET_KILL #endif @@ -307,9 +300,6 @@ static inline bool mod_between(unsigned x, unsigned i, unsigned j, unsigned m) return mod_sub(x, i, m) < mod_sub(j, i, m); } -/* FPRINTF() intentionally silences cert-err33-c clang-tidy warnings */ -#define FPRINTF(f, ...) (void)fprintf(f, __VA_ARGS__) - void raw_random(void *buf, size_t buflen); /* -- 2.53.0

inany contains a number of helpful functions for dealing with addresses which might be IPv4 or IPv6. We're going to want to use that in pesto. For the most part inany doesn't depend on other passt/pasta internals, however it does depend on siphash.h, which pesto doesn't need. Move the single dependent function, inany_siphash_feed() to siphash.h, renaming to match. Use that include inany.[ch] into pesto as well as passt/pasta. While we're there reformat pesto.c's header comment to match the convention used in most other files. Signed-off-by: David Gibson --- common.h | 20 ++++++++++++++++++-- flow.c | 4 ++-- fwd.c | 2 +- fwd.h | 1 + fwd_rule.h | 1 + inany.c | 19 ++++++++++++++----- inany.h | 17 ++--------------- pif.h | 1 + siphash.h | 13 +++++++++++++ util.h | 16 ---------------- 10 files changed, 53 insertions(+), 41 deletions(-) diff --git a/common.h b/common.h index 4a167ae0..370cfa16 100644 --- a/common.h +++ b/common.h @@ -18,9 +18,27 @@ "This is free software: you are free to change and redistribute it.\n" \ "There is NO WARRANTY, to the extent permitted by law.\n\n" +#ifndef MIN +#define MIN(x, y) (((x) < (y)) ? (x) : (y)) +#endif +#ifndef MAX +#define MAX(x, y) (((x) > (y)) ? (x) : (y)) +#endif + +#define MAX_FROM_BITS(n) (((1U << (n)) - 1)) + /* FPRINTF() intentionally silences cert-err33-c clang-tidy warnings */ #define FPRINTF(f, ...) (void)fprintf(f, __VA_ARGS__) +#define ARRAY_SIZE(a) ((int)(sizeof(a) / sizeof((a)[0]))) + +#define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d)) +#define DIV_ROUND_CLOSEST(n, d) (((n) + (d) / 2) / (d)) +#define ROUND_DOWN(x, y) ((x) & ~((y) - 1)) +#define ROUND_UP(x, y) (((x) + (y) - 1) & ~((y) - 1)) + +#define UINT16_STRLEN (sizeof("65535")) + /* * Starting from glibc 2.40.9000 and commit 25a5eb4010df ("string: strerror, * strsignal cannot use buffer after dlmopen (bug 32026)"), strerror() needs @@ -53,8 +71,6 @@ static inline const char *strerror_(int errnum) #define strerror(x) @ "Don't call strerror() directly, use strerror_() instead" -#define ARRAY_SIZE(a) ((int)(sizeof(a) / sizeof((a)[0]))) - #ifndef __bswap_constant_16 #define __bswap_constant_16(x) \ ((uint16_t) ((((x) >> 8) & 0xff) | (((x) & 0xff) << 8))) diff --git a/flow.c b/flow.c index 56a6c6d3..91f2b81f 100644 --- a/flow.c +++ b/flow.c @@ -680,8 +680,8 @@ static uint64_t flow_hash(const struct ctx *c, uint8_t proto, uint8_t pif, { struct siphash_state state = SIPHASH_INIT(c->hash_secret); - inany_siphash_feed(&state, &side->oaddr); - inany_siphash_feed(&state, &side->eaddr); + siphash_feed_inany(&state, &side->oaddr); + siphash_feed_inany(&state, &side->eaddr); return siphash_final(&state, 38, (uint64_t)proto << 40 | (uint64_t)pif << 32 | diff --git a/fwd.c b/fwd.c index 728a783c..8849cfcd 100644 --- a/fwd.c +++ b/fwd.c @@ -80,7 +80,7 @@ static size_t neigh_table_slot(const struct ctx *c, struct siphash_state st = SIPHASH_INIT(c->hash_secret); uint32_t i; - inany_siphash_feed(&st, key); + siphash_feed_inany(&st, key); i = siphash_final(&st, sizeof(*key), 0); return ((size_t)i) & (NEIGH_TABLE_SIZE - 1); diff --git a/fwd.h b/fwd.h index 8f845d09..ac247826 100644 --- a/fwd.h +++ b/fwd.h @@ -19,6 +19,7 @@ #include "fwd_rule.h" struct flowside; +struct ctx; #define FWD_NO_HINT (-1) diff --git a/fwd_rule.h b/fwd_rule.h index 58551382..f51f1b4b 100644 --- a/fwd_rule.h +++ b/fwd_rule.h @@ -13,6 +13,7 @@ #include #include +#include "common.h" #include "ip.h" #include "inany.h" #include "bitmap.h" diff --git a/inany.c b/inany.c index 2a586ed1..23faf3ff 100644 --- a/inany.c +++ b/inany.c @@ -1,9 +1,19 @@ -/* SPDX-License-Identifier: GPL-2.0-or-later - * Copyright Red Hat - * Author: David Gibson +// SPDX-License-Identifier: GPL-2.0-or-later + +/* PASST - Plug A Simple Socket Transport + * for qemu/UNIX domain socket mode + * + * PASTA - Pack A Subtle Tap Abstraction + * for network namespace/tap device mode + * + * PESTO - Programmable Extensible Socket Translation Orchestrator + * front-end for passt(1) and pasta(1) forwarding configuration * * inany.c - Types and helpers for handling addresses which could be * IPv6 or IPv4 (encoded as IPv4-mapped IPv6 addresses) + * + * Copyright Red Hat + * Author: David Gibson */ #include @@ -13,9 +23,8 @@ #include #include -#include "util.h" +#include "common.h" #include "ip.h" -#include "siphash.h" #include "inany.h" #include "fwd.h" diff --git a/inany.h b/inany.h index 1f7741d1..73385b91 100644 --- a/inany.h +++ b/inany.h @@ -11,13 +11,11 @@ #include #include +#include #include -#include "util.h" +#include "common.h" #include "ip.h" -#include "siphash.h" - -struct siphash_state; /** union inany_addr - Represents either an IPv4 or IPv6 address * @a6: Address as an IPv6 address, may be IPv4-mapped @@ -301,17 +299,6 @@ static inline int inany_from_sockaddr(union inany_addr *dst, in_port_t *port, return -1; } -/** inany_siphash_feed- Fold IPv[46] address into an in-progress siphash - * @state: siphash state - * @aa: inany to hash - */ -static inline void inany_siphash_feed(struct siphash_state *state, - const union inany_addr *aa) -{ - siphash_feed(state, (uint64_t)aa->u32[0] << 32 | aa->u32[1]); - siphash_feed(state, (uint64_t)aa->u32[2] << 32 | aa->u32[3]); -} - #define INANY_ADDRSTRLEN MAX(INET_ADDRSTRLEN, INET6_ADDRSTRLEN) bool inany_matches(const union inany_addr *a, const union inany_addr *b); diff --git a/pif.h b/pif.h index d7708603..37409d57 100644 --- a/pif.h +++ b/pif.h @@ -16,6 +16,7 @@ union inany_addr; union sockaddr_inany; +struct ctx; /** * enum pif_type - Type of passt/pasta interface ("pif") diff --git a/siphash.h b/siphash.h index bbddcac0..313b8947 100644 --- a/siphash.h +++ b/siphash.h @@ -47,6 +47,8 @@ #include #include +#include "inany.h" + /** * struct siphash_state - Internal state of siphash calculation */ @@ -101,6 +103,17 @@ static inline void siphash_feed(struct siphash_state *state, uint64_t in) state->v[0] ^= in; } +/** siphash_feed_inany() - Fold IPv[46] address into an in-progress siphash + * @state: siphash state + * @aa: inany to hash + */ +static inline void siphash_feed_inany(struct siphash_state *state, + const union inany_addr *aa) +{ + siphash_feed(state, (uint64_t)aa->u32[0] << 32 | aa->u32[1]); + siphash_feed(state, (uint64_t)aa->u32[2] << 32 | aa->u32[3]); +} + /** * siphash_final() - Finalize SipHash calculations * @v: siphash state (4 x 64-bit integers) diff --git a/util.h b/util.h index dc14c78c..70aadeba 100644 --- a/util.h +++ b/util.h @@ -29,20 +29,6 @@ #define IP_MAX_MTU USHRT_MAX #endif -#ifndef MIN -#define MIN(x, y) (((x) < (y)) ? (x) : (y)) -#endif -#ifndef MAX -#define MAX(x, y) (((x) > (y)) ? (x) : (y)) -#endif - -#define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d)) -#define DIV_ROUND_CLOSEST(n, d) (((n) + (d) / 2) / (d)) -#define ROUND_DOWN(x, y) ((x) & ~((y) - 1)) -#define ROUND_UP(x, y) (((x) + (y) - 1) & ~((y) - 1)) - -#define MAX_FROM_BITS(n) (((1U << (n)) - 1)) - #define SWAP(a, b) \ do { \ __typeof__(a) __x = (a); (a) = (b); (b) = __x; \ @@ -202,8 +188,6 @@ static inline const char *af_name(sa_family_t af) } } -#define UINT16_STRLEN (sizeof("65535")) - /* inet address (- '\0') + port (u16) (- '\0') + ':' + '\0' */ #define SOCKADDR_INET_STRLEN \ (INET_ADDRSTRLEN-1 + UINT16_STRLEN-1 + sizeof(":")) -- 2.53.0

Extend pesto to send the updated rule configuration back to passt/pasta. Extend passt/pasta to read the new configuration and store the new rules in a "pending" table. We don't yet attempt to activate them. Signed-off-by: Stefano Brivio Message-ID: <20260322141843.4095972-3-sbrivio@redhat.com> [dwg: Based on an early draft from Stefano]\ Signed-off-by: David Gibson --- Makefile | 5 ---- conf.c | 85 +++++++++++++++++++++++++++++++++++++++++++++++--------- fwd.c | 10 ++++++- passt.h | 2 ++ pesto.c | 35 +++++++++++++++++++++++ 5 files changed, 118 insertions(+), 19 deletions(-) diff --git a/Makefile b/Makefile index 125ec011..830e6299 100644 --- a/Makefile +++ b/Makefile @@ -225,10 +225,6 @@ cppcheck: passt.cppcheck passt-repair.cppcheck pesto.cppcheck qrap.cppcheck $(CPPCHECK) $(CPPCHECK_FLAGS) $(BASE_CPPFLAGS) $^ passt.cppcheck: BASE_CPPFLAGS += -UPESTO -passt.cppcheck: CPPCHECK_FLAGS += \ - --suppress=unusedFunction:fwd_rule.c \ - --suppress=staticFunction:fwd_rule.c \ - --suppress=unusedFunction:serialise.c passt.cppcheck: $(PASST_SRCS) $(PASST_HEADERS) seccomp.h passt-repair.cppcheck: $(PASST_REPAIR_SRCS) $(PASST_REPAIR_HEADERS) seccomp_repair.h @@ -239,7 +235,6 @@ pesto.cppcheck: CPPCHECK_FLAGS += \ --suppress=unusedFunction:inany.h \ --suppress=unusedFunction:inany.c \ --suppress=unusedFunction:ip.h \ - --suppress=unusedFunction:fwd_rule.c \ --suppress=staticFunction:fwd_rule.c \ --suppress=unusedFunction:serialise.c pesto.cppcheck: $(PESTO_SRCS) $(PESTO_HEADERS) seccomp_pesto.h diff --git a/conf.c b/conf.c index 1e02fbd3..243d2c7c 100644 --- a/conf.c +++ b/conf.c @@ -1971,6 +1971,53 @@ static int conf_send_rules(const struct ctx *c, int fd) return 0; } +/** + * conf_recv_rules() - Receive forwarding rules from configuration client + * @c: Execution context + * @fd: Socket to the client + * + * Return: 0 on success, -1 on failure + */ +static int conf_recv_rules(const struct ctx *c, int fd) +{ + while (1) { + struct fwd_table *fwd; + struct fwd_rule r; + uint32_t count; + uint8_t pif; + unsigned i; + + if (read_u8(fd, &pif)) + return -1; + + if (pif == PIF_NONE) + break; + + if (pif >= ARRAY_SIZE(c->fwd_pending) || + !(fwd = c->fwd_pending[pif])) { + err("Received rules for non-existent table"); + return -1; + } + + if (read_u32(fd, &count)) + return -1; + + if (count > MAX_FWD_RULES) { + err("Received %"PRIu32" rules (maximum %u)", + count, MAX_FWD_RULES); + return -1; + } + + for (i = 0; i < count; i++) { + fwd_rule_read(fd, &r); + if (fwd_rule_add(fwd, &r) < 0) + return -1; + } + } + + return 0; +} + /** * conf_close() - Close configuration / control socket and clean up * @c: Execution context @@ -2072,21 +2119,33 @@ fail: void conf_handler(struct ctx *c, uint32_t events) { if (events & EPOLLIN) { - char discard[BUFSIZ]; - ssize_t n; - - do { - n = read(c->fd_control, discard, sizeof(discard)); - if (n > 0) - debug("Discarded %zd bytes of config data", n); - } while (n > 0); - if (n == 0) { - debug("Configuration client EOF"); - goto close; + unsigned pif; + + /* Clear pending tables */ + for (pif = 0; pif < PIF_NUM_TYPES; pif++) { + struct fwd_table *fwd = c->fwd_pending[pif]; + + if (!fwd) + continue; + fwd->count = 0; + fwd->sock_count = 0; } - if (errno != EAGAIN && errno != EWOULDBLOCK) { - err_perror("Error reading config data"); + + /* FIXME: this could block indefinitely if the client doesn't + * write as much as it should + */ + if (conf_recv_rules(c, c->fd_control) < 0) goto close; + + for (pif = 0; pif < PIF_NUM_TYPES; pif++) { + struct fwd_table *fwd = c->fwd_pending[pif]; + + if (!fwd) + continue; + + info("New forwarding rules for %s:", pif_name(pif)); + fwd_rules_dump(info, fwd->rules, fwd->count, + " ", ""); } } diff --git a/fwd.c b/fwd.c index 8849cfcd..d93d2e5d 100644 --- a/fwd.c +++ b/fwd.c @@ -247,6 +247,9 @@ void fwd_neigh_table_init(const struct ctx *c) static struct fwd_table fwd_in; static struct fwd_table fwd_out; +static struct fwd_table fwd_in_pending; +static struct fwd_table fwd_out_pending; + /** * fwd_rule_init() - Initialise forwarding tables * @c: Execution context @@ -269,10 +272,15 @@ void fwd_rule_init(struct ctx *c) caps |= FWD_CAP_IFNAME; fwd_in.caps = fwd_out.caps = caps; + fwd_in_pending.caps = fwd_out_pending.caps = caps; c->fwd[PIF_HOST] = &fwd_in; - if (c->mode == MODE_PASTA) + c->fwd_pending[PIF_HOST] = &fwd_in_pending; + + if (c->mode == MODE_PASTA) { c->fwd[PIF_SPLICE] = &fwd_out; + c->fwd_pending[PIF_SPLICE] = &fwd_out_pending; + } } /** diff --git a/passt.h b/passt.h index b3f049de..1726965d 100644 --- a/passt.h +++ b/passt.h @@ -188,6 +188,7 @@ struct ip6_ctx { * @pasta_ifi: Index of namespace interface for pasta * @pasta_conf_ns: Configure namespace after creating it * @fwd: Forwarding tables + * @fwd_pending: Pending forward tables * @no_tcp: Disable TCP operation * @tcp: Context for TCP protocol handler * @no_udp: Disable UDP operation @@ -270,6 +271,7 @@ struct ctx { int pasta_conf_ns; struct fwd_table *fwd[PIF_NUM_TYPES]; + struct fwd_table *fwd_pending[PIF_NUM_TYPES]; int no_tcp; struct tcp_ctx tcp; diff --git a/pesto.c b/pesto.c index ebac6bd6..c6c595a4 100644 --- a/pesto.c +++ b/pesto.c @@ -225,6 +225,39 @@ static bool read_pif_conf(int fd, struct configuration *conf) return true; } +/** + * send_conf() - Send updated configuration to passt/pasta + * @fd: Control socket + * @conf: Updated configuration + */ +static void send_conf(int fd, const struct configuration *conf) +{ + unsigned i; + + for (i = 0; i < conf->npifs; i++) { + const struct pif_configuration *pc = &conf->pif[i]; + unsigned j; + + if (write_u8(fd, pc->pif) < 0) + goto fail; + + if (write_u32(fd, pc->fwd.count) < 0) + goto fail; + + for (j = 0; j < pc->fwd.count; j++) { + if (fwd_rule_write(fd, &pc->fwd.rules[j]) < 0) + goto fail; + } + } + + if (write_u8(fd, PIF_NONE) < 0) + goto fail; + return; + +fail: + die_perror("Error writing to control socket"); +} + /** * show_conf() - Show current configuration obtained from passt/pasta * @conf: Configuration description @@ -427,6 +460,8 @@ int main(int argc, char **argv) show_conf(&conf); } + send_conf(s, &conf); + noupdate: if (shutdown(s, SHUT_RDWR) < 0 || close(s) < 0) die_perror("Error shutting down control socket"); -- 2.53.0

We can now receive updates to the forwarding rules from the pesto client and store them in a "pending" copy of the forwarding tables. Implement switching to using the new rules. The logic is in a new fwd_listen_switch(). For now this closes all listening sockets related to the old tables, swaps the active and pending tables, then listens based on the new tables. In future we look to improve this so that we don't temporarily stop listening on ports that both the old and new tables specify. Signed-off-by: David Gibson --- conf.c | 5 ++--- fwd.c | 34 ++++++++++++++++++++++++++++++++++ fwd.h | 1 + 3 files changed, 37 insertions(+), 3 deletions(-) diff --git a/conf.c b/conf.c index 243d2c7c..affe2243 100644 --- a/conf.c +++ b/conf.c @@ -2147,15 +2147,14 @@ void conf_handler(struct ctx *c, uint32_t events) fwd_rules_dump(info, fwd->rules, fwd->count, " ", ""); } + + fwd_listen_switch(c); } if (events & EPOLLHUP) { debug("Configuration client hangup"); - goto close; } - return; - close: conf_close(c); } diff --git a/fwd.c b/fwd.c index d93d2e5d..35b9e2b0 100644 --- a/fwd.c +++ b/fwd.c @@ -534,6 +534,40 @@ int fwd_listen_init(const struct ctx *c) return 0; } +/** + * fwd_listen_switch() - Switch from current to pending rules table + * @c: Execution context + */ +void fwd_listen_switch(struct ctx *c) +{ + struct fwd_table *tmp[PIF_NUM_TYPES]; + unsigned i; + + /* Stop listening on the old tables */ + for (i = 0; i < PIF_NUM_TYPES; i++) { + struct fwd_table *fwd = c->fwd[i]; + + if (!fwd) + continue; + + debug("Flushing %u old %s rules", fwd->count, pif_name(i)); + fwd_listen_close(fwd); + fwd->count = fwd->sock_count = 0; + } + + /* Swap active and pending tables */ + static_assert(sizeof(tmp) == sizeof(c->fwd) && + sizeof(tmp) == sizeof(c->fwd_pending), + "Temporary has wrong size"); + memcpy(&tmp, (void *)c->fwd, sizeof(tmp)); + memcpy((void *)c->fwd, (void *)c->fwd_pending, sizeof(tmp)); + memcpy((void *)c->fwd_pending, &tmp, sizeof(tmp)); + + /* Start listening on the new tables */ + if (fwd_listen_init(c) < 0) + err("Error switching to new forwarding rules"); +} + /* See enum in kernel's include/net/tcp_states.h */ #define UDP_LISTEN 0x07 #define TCP_LISTEN 0x0a diff --git a/fwd.h b/fwd.h index ac247826..b60697d9 100644 --- a/fwd.h +++ b/fwd.h @@ -61,6 +61,7 @@ int fwd_listen_sync(const struct ctx *c, uint8_t pif, const struct fwd_scan *tcp, const struct fwd_scan *udp); void fwd_listen_close(const struct fwd_table *fwd); int fwd_listen_init(const struct ctx *c); +void fwd_listen_switch(struct ctx *c); bool nat_inbound(const struct ctx *c, const union inany_addr *addr, union inany_addr *translated); -- 2.53.0

On 2026-04-21 02:25, David Gibson wrote:

Extend pesto to send the updated rule configuration back to passt/pasta. Extend passt/pasta to read the new configuration and store the new rules in a "pending" table. We don't yet attempt to activate them.

Signed-off-by: Stefano Brivio Message-ID: <20260322141843.4095972-3-sbrivio@redhat.com> [dwg: Based on an early draft from Stefano]\ Signed-off-by: David Gibson

[...]

+/** + * conf_recv_rules() - Receive forwarding rules from configuration client + * @c: Execution context + * @fd: Socket to the client + * + * Return: 0 on success, -1 on failure + */ +static int conf_recv_rules(const struct ctx *c, int fd) +{ + while (1) { + struct fwd_table *fwd; + struct fwd_rule r; + uint32_t count; + uint8_t pif; + unsigned i; + + if (read_u8(fd, &pif)) + return -1; + + if (pif == PIF_NONE) + break; + + if (pif >= ARRAY_SIZE(c->fwd_pending) || + !(fwd = c->fwd_pending[pif])) { + err("Received rules for non-existent table"); + return -1; + } + + if (read_u32(fd, &count)) + return -1; + + if (count > MAX_FWD_RULES) { + err("Received %"PRIu32" rules (maximum %u)", + count, MAX_FWD_RULES); + return -1; + } + + for (i = 0; i < count; i++) { + fwd_rule_read(fd, &r);

Since we don't check the return value I think we risk passing an only partially initialized fwd_rule to fwd_rule_add() if the read fails. Maybe: if (fwd_rule_read(fd, &r)) return -1; /jon

+ if (fwd_rule_add(fwd, &r) < 0) + return -1; + } + } + + return 0; +} + /** * conf_close() - Close configuration / control socket and clean up * @c: Execution context @@ -2072,21 +2119,33 @@ fail: void conf_handler(struct ctx *c, uint32_t events) { if (events & EPOLLIN) { - char discard[BUFSIZ]; - ssize_t n; - - do { - n = read(c->fd_control, discard, sizeof(discard)); - if (n > 0) - debug("Discarded %zd bytes of config data", n); - } while (n > 0); - if (n == 0) { - debug("Configuration client EOF"); - goto close; + unsigned pif; + + /* Clear pending tables */ + for (pif = 0; pif < PIF_NUM_TYPES; pif++) { + struct fwd_table *fwd = c->fwd_pending[pif]; + + if (!fwd) + continue; + fwd->count = 0; + fwd->sock_count = 0; } - if (errno != EAGAIN && errno != EWOULDBLOCK) { - err_perror("Error reading config data"); + + /* FIXME: this could block indefinitely if the client doesn't + * write as much as it should + */ + if (conf_recv_rules(c, c->fd_control) < 0) goto close; + + for (pif = 0; pif < PIF_NUM_TYPES; pif++) { + struct fwd_table *fwd = c->fwd_pending[pif]; + + if (!fwd) + continue; + + info("New forwarding rules for %s:", pif_name(pif)); + fwd_rules_dump(info, fwd->rules, fwd->count, + " ", ""); } }

diff --git a/fwd.c b/fwd.c index 8849cfcd..d93d2e5d 100644 --- a/fwd.c +++ b/fwd.c @@ -247,6 +247,9 @@ void fwd_neigh_table_init(const struct ctx *c) static struct fwd_table fwd_in; static struct fwd_table fwd_out;

+static struct fwd_table fwd_in_pending; +static struct fwd_table fwd_out_pending; + /** * fwd_rule_init() - Initialise forwarding tables * @c: Execution context @@ -269,10 +272,15 @@ void fwd_rule_init(struct ctx *c) caps |= FWD_CAP_IFNAME;

fwd_in.caps = fwd_out.caps = caps; + fwd_in_pending.caps = fwd_out_pending.caps = caps;

c->fwd[PIF_HOST] = &fwd_in; - if (c->mode == MODE_PASTA) + c->fwd_pending[PIF_HOST] = &fwd_in_pending; + + if (c->mode == MODE_PASTA) { c->fwd[PIF_SPLICE] = &fwd_out; + c->fwd_pending[PIF_SPLICE] = &fwd_out_pending; + } }

/** diff --git a/passt.h b/passt.h index b3f049de..1726965d 100644 --- a/passt.h +++ b/passt.h @@ -188,6 +188,7 @@ struct ip6_ctx { * @pasta_ifi: Index of namespace interface for pasta * @pasta_conf_ns: Configure namespace after creating it * @fwd: Forwarding tables + * @fwd_pending: Pending forward tables * @no_tcp: Disable TCP operation * @tcp: Context for TCP protocol handler * @no_udp: Disable UDP operation @@ -270,6 +271,7 @@ struct ctx { int pasta_conf_ns;

struct fwd_table *fwd[PIF_NUM_TYPES]; + struct fwd_table *fwd_pending[PIF_NUM_TYPES];

int no_tcp; struct tcp_ctx tcp; diff --git a/pesto.c b/pesto.c index ebac6bd6..c6c595a4 100644 --- a/pesto.c +++ b/pesto.c @@ -225,6 +225,39 @@ static bool read_pif_conf(int fd, struct configuration *conf) return true; }

+/** + * send_conf() - Send updated configuration to passt/pasta + * @fd: Control socket + * @conf: Updated configuration + */ +static void send_conf(int fd, const struct configuration *conf) +{ + unsigned i; + + for (i = 0; i < conf->npifs; i++) { + const struct pif_configuration *pc = &conf->pif[i]; + unsigned j; + + if (write_u8(fd, pc->pif) < 0) + goto fail; + + if (write_u32(fd, pc->fwd.count) < 0) + goto fail; + + for (j = 0; j < pc->fwd.count; j++) { + if (fwd_rule_write(fd, &pc->fwd.rules[j]) < 0) + goto fail; + } + } + + if (write_u8(fd, PIF_NONE) < 0) + goto fail; + return; + +fail: + die_perror("Error writing to control socket"); +} + /** * show_conf() - Show current configuration obtained from passt/pasta * @conf: Configuration description @@ -427,6 +460,8 @@ int main(int argc, char **argv) show_conf(&conf); }

+ send_conf(s, &conf); + noupdate: if (shutdown(s, SHUT_RDWR) < 0 || close(s) < 0) die_perror("Error shutting down control socket");

On 2026-04-21 02:25, David Gibson wrote:

Extend the dynamic update protocol to expose the pif indices and names from a running passt/pasta to the pesto tool. pesto records that data and, if requested with a new --show flag, prints it out.

Signed-off-by: David Gibson --- Makefile | 1 + common.h | 2 + conf.c | 41 ++++++++++++++++ pesto.c | 132 ++++++++++++++++++++++++++++++++++++++++++++++++++++ pesto.h | 19 +++++++- pif.h | 4 +- serialise.c | 4 ++ serialise.h | 1 + util.h | 2 - 9 files changed, 200 insertions(+), 6 deletions(-)

[...]

diff --git a/pesto.h b/pesto.h index 92d4df3a..ac4c2b58 100644 --- a/pesto.h +++ b/pesto.h @@ -17,18 +17,33 @@ /* Version 0 is reserved for unreleased / unsupported experimental versions */ #define PESTO_PROTOCOL_VERSION 0

+/* Maxmimum size of a pif name, including \0 */ +#define PIF_NAME_SIZE (128) +#define PIF_NONE 0 + /** * struct pesto_hello - Server introduction message - * @magic: PESTO_SERVER_MAGIC - * @version: Version number + * @magic: PESTO_SERVER_MAGIC + * @version: Version number + * @pif_name_size: Server's value for PIF_NAME_SIZE */ struct pesto_hello { char magic[8]; uint32_t version; + uint32_t pif_name_size; } __attribute__ ((__packed__));

static_assert(sizeof(PESTO_SERVER_MAGIC) == sizeof(((struct pesto_hello *)0)->magic), "PESTO_SERVER_MAGIC has wrong size");

+/** + * struct pesto_pif_info - Message with basic metadata about a pif + * @resv_: Alignment gap (must be 0)

You forgot to remove this one.

+ * @name: Name (\0 terminated) + */ +struct pesto_pif_info { + char name[PIF_NAME_SIZE]; +} __attribute__ ((__packed__)); + #endif /* PESTO_H */ diff --git a/pif.h b/pif.h index 90dd3a32..d7708603 100644 --- a/pif.h +++ b/pif.h @@ -11,6 +11,7 @@

#include

+#include "pesto.h" #include "epoll_type.h"

union inany_addr; @@ -24,7 +25,7 @@ union sockaddr_inany; */ enum pif_type { /* Invalid or not present pif */ - PIF_NONE = 0, + PIF_NONE_ = PIF_NONE,

This looks a bit weird. As fara as I can see this one is never used. If it is important that PIF_NONE is zero and PIF_HOST is 1, you could just do: enum pif_type { PIF_HOST = 1, PIF_TAP, PIF_SPLICE, PIF_NUM_TYPES, }; or #define PESTO_PIF_END 0 in pesto.h and leave this one as is. /jon [...] item) - (array) < ARRAY_SIZE(array); (item)++)

On Sun, Apr 26, 2026 at 09:45:06AM -0400, Jon Maloy wrote:

On 2026-04-21 02:25, David Gibson wrote:

...

Start implementing pesto in earnest. Create a control/configuration socket in passt. Have pesto connect to it and retrieve a server greeting Perform some basic version checking.

[...]

...

/** * conf() - Process command-line arguments and set configuration * @c: Execution context @@ -1189,9 +1227,10 @@ void conf(struct ctx *c, int argc, char **argv) {"migrate-exit", no_argument, NULL, 29 }, {"migrate-no-linger", no_argument, NULL, 30 }, {"stats", required_argument, NULL, 31 }, + {"conf-path", required_argument, NULL, 'c' }, { 0 }, }; - const char *optstring = "+dqfel:hs:F:I:p:P:m:a:n:M:g:i:o:D:S:H:461t:u:T:U:"; + const char *optstring = "+dqfel:hs:c:F:I:p:P:m:a:n:M:g:i:o:D:S:H:461t:u:T:U:"; const char *logname = (c->mode == MODE_PASTA) ? "pasta" : "passt"; bool opt_t = false, opt_T = false, opt_u = false, opt_U = false; char userns[PATH_MAX] = { 0 }, netns[PATH_MAX] = { 0 }; @@ -1449,6 +1488,13 @@ void conf(struct ctx *c, int argc, char **argv) c->fd_tap = -1; break; + case 'c': + ret = snprintf(c->control_path, sizeof(c->control_path), + "%s", optarg); + if (ret <= 0 || ret >= (int)sizeof(c->sock_path))

s/sizeof(c->sock_path)/sizeof(c->config_path)/

Oops, yes. [snip]

...

@@ -122,5 +128,42 @@ int main(int argc, char **argv) debug("debug_flag=%d, path=\"%s\"", debug_flag, argv[optind]); - die("pesto is not implemented yet"); + if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) + die_perror("Failed to create AF_UNIX socket"); + + ret = snprintf(a.sun_path, sizeof(a.sun_path), "%s", argv[optind]); + if (ret <= 0 || ret >= (int)sizeof(a.sun_path)) + die("Invalid socket path \"%s\"", argv[1]);

s/argv[1]/argv[optind] for consistency.

And again. This is not just for consistency, but for correctness (of the error message). Depending on the command line, optind may not be equal to 1. -- David Gibson (he or they) | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you, not the other way | around. http://www.ozlabs.org/~dgibson

On Sun, Apr 26, 2026 at 09:45:14AM -0400, Jon Maloy wrote:

On 2026-04-21 02:25, David Gibson wrote:

...

Extend the dynamic update protocol to expose the pif indices and names from a running passt/pasta to the pesto tool. pesto records that data and, if requested with a new --show flag, prints it out.

Signed-off-by: David Gibson --- Makefile | 1 + common.h | 2 + conf.c | 41 ++++++++++++++++ pesto.c | 132 ++++++++++++++++++++++++++++++++++++++++++++++++++++ pesto.h | 19 +++++++- pif.h | 4 +- serialise.c | 4 ++ serialise.h | 1 + util.h | 2 - 9 files changed, 200 insertions(+), 6 deletions(-)

[...]

...

diff --git a/pesto.h b/pesto.h index 92d4df3a..ac4c2b58 100644 --- a/pesto.h +++ b/pesto.h @@ -17,18 +17,33 @@ /* Version 0 is reserved for unreleased / unsupported experimental versions */ #define PESTO_PROTOCOL_VERSION 0 +/* Maxmimum size of a pif name, including \0 */ +#define PIF_NAME_SIZE (128) +#define PIF_NONE 0 + /** * struct pesto_hello - Server introduction message - * @magic: PESTO_SERVER_MAGIC - * @version: Version number + * @magic: PESTO_SERVER_MAGIC + * @version: Version number + * @pif_name_size: Server's value for PIF_NAME_SIZE */ struct pesto_hello { char magic[8]; uint32_t version; + uint32_t pif_name_size; } __attribute__ ((__packed__)); static_assert(sizeof(PESTO_SERVER_MAGIC) == sizeof(((struct pesto_hello *)0)->magic), "PESTO_SERVER_MAGIC has wrong size"); +/** + * struct pesto_pif_info - Message with basic metadata about a pif + * @resv_: Alignment gap (must be 0)

You forgot to remove this one.

Oops, yes.

...

+ * @name: Name (\0 terminated) + */ +struct pesto_pif_info { + char name[PIF_NAME_SIZE]; +} __attribute__ ((__packed__)); + #endif /* PESTO_H */ diff --git a/pif.h b/pif.h index 90dd3a32..d7708603 100644 --- a/pif.h +++ b/pif.h @@ -11,6 +11,7 @@ #include +#include "pesto.h" #include "epoll_type.h" union inany_addr; @@ -24,7 +25,7 @@ union sockaddr_inany; */ enum pif_type { /* Invalid or not present pif */ - PIF_NONE = 0, + PIF_NONE_ = PIF_NONE,

This looks a bit weird.

Yes, but it seemed less weird that the other approaches I could think of to do what I needed. The key point here is that the specific value of PIF_NONE is locked as part of the configuration protocol. The values of all other pif indices are (intentionally) passt internal and should not be known by the client.

As fara as I can see this one is never used.

Yes, that's correct.

If it is important that PIF_NONE is zero and PIF_HOST is 1,

It's important that PIF_NONE is zero. It's not important that PIF_HOST is 1.

you could just do:

enum pif_type {

PIF_HOST = 1,

PIF_TAP, PIF_SPLICE,

PIF_NUM_TYPES, };

I could, but I think this makes the connection between the public PIF_NONE and the private PIF_* less obvious.

or #define PESTO_PIF_END 0 in pesto.h and leave this one as is.

I could - indeed an earlier draft did essentially this. Hoewver, that wouldn't enforce that PIF_NONE is equal to the terminator value, which it should be.

/jon

[...]

item) - (array) < ARRAY_SIZE(array); (item)++)

-- David Gibson (he or they) | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you, not the other way | around. http://www.ozlabs.org/~dgibson

On Wed, 29 Apr 2026 15:17:34 +1000 David Gibson wrote:

On Sun, Apr 26, 2026 at 09:45:14AM -0400, Jon Maloy wrote:

...

On 2026-04-21 02:25, David Gibson wrote:

...

Extend the dynamic update protocol to expose the pif indices and names from a running passt/pasta to the pesto tool. pesto records that data and, if requested with a new --show flag, prints it out.

Signed-off-by: David Gibson --- Makefile | 1 + common.h | 2 + conf.c | 41 ++++++++++++++++ pesto.c | 132 ++++++++++++++++++++++++++++++++++++++++++++++++++++ pesto.h | 19 +++++++- pif.h | 4 +- serialise.c | 4 ++ serialise.h | 1 + util.h | 2 - 9 files changed, 200 insertions(+), 6 deletions(-)

[...]

...

diff --git a/pesto.h b/pesto.h index 92d4df3a..ac4c2b58 100644 --- a/pesto.h +++ b/pesto.h @@ -17,18 +17,33 @@ /* Version 0 is reserved for unreleased / unsupported experimental versions */ #define PESTO_PROTOCOL_VERSION 0 +/* Maxmimum size of a pif name, including \0 */ +#define PIF_NAME_SIZE (128) +#define PIF_NONE 0 + /** * struct pesto_hello - Server introduction message - * @magic: PESTO_SERVER_MAGIC - * @version: Version number + * @magic: PESTO_SERVER_MAGIC + * @version: Version number + * @pif_name_size: Server's value for PIF_NAME_SIZE */ struct pesto_hello { char magic[8]; uint32_t version; + uint32_t pif_name_size; } __attribute__ ((__packed__)); static_assert(sizeof(PESTO_SERVER_MAGIC) == sizeof(((struct pesto_hello *)0)->magic), "PESTO_SERVER_MAGIC has wrong size"); +/** + * struct pesto_pif_info - Message with basic metadata about a pif + * @resv_: Alignment gap (must be 0)

You forgot to remove this one.

Oops, yes.

Fixed in v6.

...

...

+ * @name: Name (\0 terminated) + */ +struct pesto_pif_info { + char name[PIF_NAME_SIZE]; +} __attribute__ ((__packed__)); + #endif /* PESTO_H */ diff --git a/pif.h b/pif.h index 90dd3a32..d7708603 100644 --- a/pif.h +++ b/pif.h @@ -11,6 +11,7 @@ #include +#include "pesto.h" #include "epoll_type.h" union inany_addr; @@ -24,7 +25,7 @@ union sockaddr_inany; */ enum pif_type { /* Invalid or not present pif */ - PIF_NONE = 0, + PIF_NONE_ = PIF_NONE,

This looks a bit weird.

Yes, but it seemed less weird that the other approaches I could think of to do what I needed. The key point here is that the specific value of PIF_NONE is locked as part of the configuration protocol. The values of all other pif indices are (intentionally) passt internal and should not be known by the client.

...

As fara as I can see this one is never used.

Yes, that's correct.

...

If it is important that PIF_NONE is zero and PIF_HOST is 1,

It's important that PIF_NONE is zero. It's not important that PIF_HOST is 1.

...

you could just do:

enum pif_type {

PIF_HOST = 1,

PIF_TAP, PIF_SPLICE,

PIF_NUM_TYPES, };

I could, but I think this makes the connection between the public PIF_NONE and the private PIF_* less obvious.

...

or #define PESTO_PIF_END 0 in pesto.h and leave this one as is.

I could - indeed an earlier draft did essentially this. Hoewver, that wouldn't enforce that PIF_NONE is equal to the terminator value, which it should be.

Left as it was in v6. -- Stefano