- dev - passt

[PATCH v2] conf: Fix typo and logic in conf_ports() check for port binding
by Stefano Brivio 16 Feb '23

16 Feb '23

Ouch, I accidentally pushed the previous change without running the tests: - we need to check, in conf_ports(), that udp_sock_init() managed to bind at least a port, not the opposite - for -T and -U, we have no way to know if we'll manage to bind the port later, so never report an error for those Fixes: 3d0de2c1d727 ("conf, tcp, udp: Exit if we fail to bind sockets for all given ports") Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com> --- v2: Add the special case for -T and -U conf.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/conf.c b/conf.c index 5426c9b..4dc0660 100644 --- a/conf.c +++ b/conf.c @@ -306,6 +306,9 @@ static void conf_ports(const struct ctx *c, char optname, const char *optarg, } else if (optname == 'u') { if (!udp_sock_init(c, 0, af, addr, ifname, i)) bound_one = true; + } else { + /* No way to check in advance for -T and -U */ + bound_one = true; } } @@ -356,8 +359,11 @@ static void conf_ports(const struct ctx *c, char optname, const char *optarg, if (!tcp_sock_init(c, af, addr, ifname, i)) bound_one = true; } else if (optname == 'u') { - if (udp_sock_init(c, 0, af, addr, ifname, i)) + if (!udp_sock_init(c, 0, af, addr, ifname, i)) bound_one = true; + } else { + /* No way to check in advance for -T and -U */ + bound_one = true; } } } while ((p = next_chunk(p, ','))); -- 2.35.1

1 0

[PATCH] conf: Fix typo in conf_ports() check for UDP port binding
by Stefano Brivio 16 Feb '23

16 Feb '23

Ouch, I accidentally pushed the previous change without running the tests: we need to check, in conf_ports(), that udp_sock_init() managed to bind at least a port, not the opposite. Fixes: 3d0de2c1d727 ("conf, tcp, udp: Exit if we fail to bind sockets for all given ports") Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com> --- conf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/conf.c b/conf.c index 5426c9b..60ca399 100644 --- a/conf.c +++ b/conf.c @@ -356,7 +356,7 @@ static void conf_ports(const struct ctx *c, char optname, const char *optarg, if (!tcp_sock_init(c, af, addr, ifname, i)) bound_one = true; } else if (optname == 'u') { - if (udp_sock_init(c, 0, af, addr, ifname, i)) + if (!udp_sock_init(c, 0, af, addr, ifname, i)) bound_one = true; } } -- 2.35.1

1 0

[PATCH v2] passt.1: Fix typo, improve wording in examples of port forwarding specifiers
by Stefano Brivio 16 Feb '23

16 Feb '23

Based on a patch from Laine, and reports from Laine and Yalan: fix the "22-80:32-90" example, and improve wording for the other ones: instead of using "to" to denote the end of a range, use "between ... and", so that it's clear we're *not* referring to target ports. Reported-by: Laine Stump <laine(a)redhat.com> Reported-by: Yalan Zhang <yalzhang(a)redhat.com> Fixes: da20f57f19dc ("passt, qrap: Add man pages") Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com> --- v2: Adopted further changes proposed by David passt.1 | 29 +++++++++++++++++------------ 1 file changed, 17 insertions(+), 12 deletions(-) diff --git a/passt.1 b/passt.1 index 528763b..f317c33 100644 --- a/passt.1 +++ b/passt.1 @@ -338,7 +338,7 @@ Examples: .RS .TP -t 22 -Forward local port 22 to 22 on the guest +Forward local port 22 to port 22 on the guest .TP -t 22:23 Forward local port 22 to port 23 on the guest @@ -347,10 +347,10 @@ Forward local port 22 to port 23 on the guest Forward local ports 22 and 25 to ports 22 and 25 on the guest .TP -t 22-80 -Forward local ports 22 to 80 to corresponding ports on the guest +Forward local ports between 22 and 80 to corresponding ports on the guest .TP --t 22-80-32:90 -Forward local ports 22 to 80 to corresponding ports on the guest plus 10 +-t 22-80:32-90 +Forward local ports between 22 and 80 to ports between 32 and 90 on the guest .TP -t 192.0.2.1/22 Forward local port 22, bound to 192.0.2.1, to port 22 on the guest @@ -359,10 +359,12 @@ Forward local port 22, bound to 192.0.2.1, to port 22 on the guest Forward local port 22, bound to 192.0.2.1 and interface eth0, to port 22 .TP -t 2000-5000,~3000-3010 -Forward local ports 2000 to 5000, but not 3000 to 3010 +Forward local ports between 2000 and 5000, except for those between 3000 and +3010 .TP -t 192.0.2.1/20-30,~25 -Forward local ports 20 to 24, and 26 to 30, bound to 192.0.2.1 +For the local address 192.0.2.1, forward ports between 20 and 24 and between 26 +and 30 .TP -t ~20000-20010 Forward all ports to the guest, except for the range from 20000 to 20010 @@ -425,10 +427,11 @@ Forward local port 22 to port 23 in the target namespace Forward local ports 22 and 25 to ports 22 and 25 in the target namespace .TP -t 22-80 -Forward local ports 22 to 80 to corresponding ports in the target namespace +Forward local ports between 22 and 80 to corresponding ports in the target +namespace .TP --t 22-80-32:90 -Forward local ports 22 to 80 to corresponding ports plus 10 in the target +-t 22-80:32-90 +Forward local ports between 22 and 80 to ports between 32 and 90 in the target namespace .TP -t 192.0.2.1/22 @@ -438,13 +441,15 @@ Forward local port 22, bound to 192.0.2.1, to port 22 in the target namespace Forward local port 22, bound to 192.0.2.1 and interface eth0, to port 22 .TP -t 2000-5000,~3000-3010 -Forward local ports 2000 to 5000, but not 3000 to 3010 +Forward local ports between 2000 and 5000, except for those between 3000 and +3010 .TP -t 192.0.2.1/20-30,~25 -Forward local ports 20 to 24, and 26 to 30, bound to 192.0.2.1 +For the local address 192.0.2.1, forward ports between 20 and 24 and between 26 +and 30 .TP -t ~20000-20010 -Forward all ports to the namespace, except for the range from 20000 to 20010 +Forward all ports to the namespace, except for those between 20000 and 20010 .RE IPv6 bound ports are also forwarded for IPv4. -- 2.35.1

2 3

[PATCH 0/4] qemu_passt: Don't let passt fork off
by Michal Privoznik 16 Feb '23

16 Feb '23

Here are some cleanup, as promised here: https://listman.redhat.com/archives/libvir-list/2023-February/237721.html Now, there are still some patches missing. Firstly, we still don't really capture error from passt. My suggestion was to wait for socket to show up with errfd open. But active wait is viewed as undesirable [1]. Secondly, Laine reported SELinux issues. Yeah, I don't see us setting SELinux label on nor socket that passt and QEMU talk to each other, nor on the log file. Speaking of which - we usually have per domain (or per helper daemon instance even) log file, while for passt we have a global one (/var/log/passt.log). I don't think that will fly if two or more SELinux enabled domains want to use passt. Thirdly, Stefano suggested a graceful shutdown for passt: have libvirt connect to the socket and close it. Since we pass --one-off, this should singal passt to exit. But I haven't implemented that because it's redundant. We can't rely on passt quitting itself and thus use the big gun (virPidFileForceCleanupPath()) at which point, the socket way is just an optimization. I might look into the first two, at some point. But not today. 1: https://listman.redhat.com/archives/libvir-list/2023-February/237663.html Michal Prívozník (4): Revert "qemu: allow passt to self-daemonize" qemu_extdevice: Make qemuExtDevicesHasDevice() check def->nets qemu_passt: Report error when getting passt PID failed qemu_passt: Don't let passt fork off src/qemu/qemu_extdevice.c | 11 +++++++++++ src/qemu/qemu_passt.c | 15 ++++++++++----- 2 files changed, 21 insertions(+), 5 deletions(-) -- 2.39.1

5 18

[PATCH 0/4] RFC: Some cleanups to tap and tcp
by David Gibson 16 Feb '23

16 Feb '23

This is a handful of simple cleanups which I made while investigating https://bugs.passt.top/show_bug.cgi?id=41. Note that these don't themselves actually address that bug, they're just unrelated cleanups that happen to be in adjacent code. These are barely tested at all. I've had some crises right before going away that mean I haven't had a chance to plish these. I'm posting them so they're out there rather than waiting until I'm back in two weeks. These are based on my tap send unification series and the TCP socket pool cleanup series. David Gibson (4): tap: Don't pcap frames that didn't get sent tap: Eliminate goto from tap_handler() tcp: Remove 'recvmsg' goto from tcp_data_from_sock tcp: Remove 'zero_len' goto from tcp_data_from_sock tap.c | 49 +++++++++++++++++++++++++++---------------------- tcp.c | 37 +++++++++++++++++-------------------- 2 files changed, 44 insertions(+), 42 deletions(-) -- 2.39.1

2 9

[PATCH] passt.1: Fix typo, improve wording in examples of port forwarding specifiers
by Stefano Brivio 16 Feb '23

16 Feb '23

Based on a patch from Laine, and reports from Laine and Yalan: fix the "22-80:32-90" example, and improve wording for the other ones: instead of using "to" to denote the end of a range, use "between ... and", so that it's clear we're *not* referring to target ports. Reported-by: Laine Stump <laine(a)redhat.com> Reported-by: Yalan Zhang <yalzhang(a)redhat.com> Fixes: da20f57f19dc ("passt, qrap: Add man pages") Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com> --- passt.1 | 29 ++++++++++++++++------------- 1 file changed, 16 insertions(+), 13 deletions(-) diff --git a/passt.1 b/passt.1 index 528763b..ec09c22 100644 --- a/passt.1 +++ b/passt.1 @@ -338,7 +338,7 @@ Examples: .RS .TP -t 22 -Forward local port 22 to 22 on the guest +Forward local port 22 to port 22 on the guest .TP -t 22:23 Forward local port 22 to port 23 on the guest @@ -347,10 +347,11 @@ Forward local port 22 to port 23 on the guest Forward local ports 22 and 25 to ports 22 and 25 on the guest .TP -t 22-80 -Forward local ports 22 to 80 to corresponding ports on the guest +Forward local ports between 22 and 80 to corresponding ports on the guest .TP --t 22-80-32:90 -Forward local ports 22 to 80 to corresponding ports on the guest plus 10 +-t 22-80:32-90 +Forward local ports between 22 and 80 to corresponding ports on the guest, plus +10 .TP -t 192.0.2.1/22 Forward local port 22, bound to 192.0.2.1, to port 22 on the guest @@ -359,10 +360,10 @@ Forward local port 22, bound to 192.0.2.1, to port 22 on the guest Forward local port 22, bound to 192.0.2.1 and interface eth0, to port 22 .TP -t 2000-5000,~3000-3010 -Forward local ports 2000 to 5000, but not 3000 to 3010 +Forward local ports between 2000 and 5000, but not between 3000 to 3010 .TP -t 192.0.2.1/20-30,~25 -Forward local ports 20 to 24, and 26 to 30, bound to 192.0.2.1 +Forward local ports between 20 to 24, and between 26 to 30, bound to 192.0.2.1 .TP -t ~20000-20010 Forward all ports to the guest, except for the range from 20000 to 20010 @@ -425,12 +426,13 @@ Forward local port 22 to port 23 in the target namespace Forward local ports 22 and 25 to ports 22 and 25 in the target namespace .TP -t 22-80 -Forward local ports 22 to 80 to corresponding ports in the target namespace -.TP --t 22-80-32:90 -Forward local ports 22 to 80 to corresponding ports plus 10 in the target +Forward local ports between 22 and 80 to corresponding ports in the target namespace .TP +-t 22-80:32-90 +Forward local ports between 22 and 80 to corresponding ports, plus 10, in the +target namespace +.TP -t 192.0.2.1/22 Forward local port 22, bound to 192.0.2.1, to port 22 in the target namespace .TP @@ -438,13 +440,14 @@ Forward local port 22, bound to 192.0.2.1, to port 22 in the target namespace Forward local port 22, bound to 192.0.2.1 and interface eth0, to port 22 .TP -t 2000-5000,~3000-3010 -Forward local ports 2000 to 5000, but not 3000 to 3010 +Forward local ports between 2000 and 5000, but not between 3000 to 3010 .TP -t 192.0.2.1/20-30,~25 -Forward local ports 20 to 24, and 26 to 30, bound to 192.0.2.1 +Forward local ports between 20 to 24, and between 26 to 30, bound to 192.0.2.1 .TP -t ~20000-20010 -Forward all ports to the namespace, except for the range from 20000 to 20010 +Forward all ports to the target namespace, except for the range from 20000 to +20010 .RE IPv6 bound ports are also forwarded for IPv4. -- 2.35.1

2 2

[PATCH] log: Don't duplicate messages on stderr before daemonising
by Stefano Brivio 16 Feb '23

16 Feb '23

Now that logging functions force printing messages to stderr before passt forks to background, we'll have duplicate messages when running from an interactive terminal, or if --stderr is passed, because at some point we set LOG_PERROR in our __openlog() wrapper. We could defer setting LOG_PERROR, but that would change option semantics in other, unexpected ways. We could force calling passt_vsyslog() as long as the mask is set to LOG_EMERG, but that complicates the logic in logging functions even further. Go the easy way for now: don't force printing to stderr with LOG_EMERG if LOG_PERROR is already set. We should seriously consider a rework of those logging functions at this point. Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com> --- This applies on top of Laine's series. log.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/log.c b/log.c index 785bc36..f23e8ef 100644 --- a/log.c +++ b/log.c @@ -44,6 +44,8 @@ static char log_header[BUFSIZ]; /* File header, written back on cuts */ static time_t log_start; /* Start timestamp */ int log_trace; /* --trace mode enabled */ +#define BEFORE_DAEMON (setlogmask(0) == LOG_MASK(LOG_EMERG)) + #define logfn(name, level, doexit) \ void name(const char *format, ...) { \ struct timespec tp; \ @@ -56,8 +58,7 @@ void name(const char *format, ...) { \ tp.tv_nsec / (100L * 1000)); \ } \ \ - if ((LOG_MASK(LOG_PRI(level)) & log_mask) || \ - setlogmask(0) == LOG_MASK(LOG_EMERG)) { \ + if ((LOG_MASK(LOG_PRI(level)) & log_mask) || BEFORE_DAEMON) { \ va_start(args, format); \ if (log_file != -1) \ logfile_write(level, format, args); \ @@ -67,7 +68,7 @@ void name(const char *format, ...) { \ } \ \ if ((setlogmask(0) & LOG_MASK(LOG_DEBUG) && log_file == -1) || \ - setlogmask(0) == LOG_MASK(LOG_EMERG)) { \ + (BEFORE_DAEMON && !(log_opt & LOG_PERROR))) { \ va_start(args, format); \ (void)vfprintf(stderr, format, args); \ va_end(args); \ -- 2.35.1

2 1

[PATCH] conf, tcp, udp: Exit if we fail to bind sockets for all given ports
by Stefano Brivio 16 Feb '23

16 Feb '23

passt supports ranges of forwarded ports as well as 'all' for TCP and UDP, so it might be convenient to proceed if we fail to bind only some of the desired ports. But if we fail to bind even a single port for a given specification, we're clearly, unexpectedly, conflicting with another network service. In that case, report failure and exit. Reported-by: Yalan Zhang <yalzhang(a)redhat.com> Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com> --- conf.c | 47 ++++++++++++++++++++++++++++++++++------------- tcp.c | 25 ++++++++++++++++++------- tcp.h | 4 ++-- udp.c | 16 +++++++++++++--- udp.h | 4 ++-- 5 files changed, 69 insertions(+), 27 deletions(-) diff --git a/conf.c b/conf.c index f175405..675d961 100644 --- a/conf.c +++ b/conf.c @@ -179,9 +179,9 @@ static void conf_ports(const struct ctx *c, char optname, const char *optarg, { char addr_buf[sizeof(struct in6_addr)] = { 0 }, *addr = addr_buf; char buf[BUFSIZ], *spec, *ifname = NULL, *p; + bool exclude_only = true, bound_one = false; uint8_t exclude[PORT_BITMAP_SIZE] = { 0 }; sa_family_t af = AF_UNSPEC; - bool exclude_only = true; if (!strcmp(optarg, "none")) { if (fwd->mode) @@ -215,12 +215,19 @@ static void conf_ports(const struct ctx *c, char optname, const char *optarg, memset(fwd->map, 0xff, PORT_EPHEMERAL_MIN / 8); for (i = 0; i < PORT_EPHEMERAL_MIN; i++) { - if (optname == 't') - tcp_sock_init(c, AF_UNSPEC, NULL, NULL, i); - else if (optname == 'u') - udp_sock_init(c, 0, AF_UNSPEC, NULL, NULL, i); + if (optname == 't') { + if (!tcp_sock_init(c, AF_UNSPEC, NULL, NULL, i)) + bound_one = true; + } else if (optname == 'u') { + if (!udp_sock_init(c, 0, AF_UNSPEC, NULL, NULL, + i)) + bound_one = true; + } } + if (!bound_one) + goto bind_fail; + return; } @@ -293,12 +300,18 @@ static void conf_ports(const struct ctx *c, char optname, const char *optarg, bitmap_set(fwd->map, i); - if (optname == 't') - tcp_sock_init(c, af, addr, ifname, i); - else if (optname == 'u') - udp_sock_init(c, 0, af, addr, ifname, i); + if (optname == 't') { + if (!tcp_sock_init(c, af, addr, ifname, i)) + bound_one = true; + } else if (optname == 'u') { + if (!udp_sock_init(c, 0, af, addr, ifname, i)) + bound_one = true; + } } + if (!bound_one) + goto bind_fail; + return; } @@ -339,13 +352,19 @@ static void conf_ports(const struct ctx *c, char optname, const char *optarg, fwd->delta[i] = mapped_range.first - orig_range.first; - if (optname == 't') - tcp_sock_init(c, af, addr, ifname, i); - else if (optname == 'u') - udp_sock_init(c, 0, af, addr, ifname, i); + if (optname == 't') { + if (!tcp_sock_init(c, af, addr, ifname, i)) + bound_one = true; + } else if (optname == 'u') { + if (udp_sock_init(c, 0, af, addr, ifname, i)) + bound_one = true; + } } } while ((p = next_chunk(p, ','))); + if (!bound_one) + goto bind_fail; + return; bad: die("Invalid port specifier %s", optarg); @@ -353,6 +372,8 @@ overlap: die("Overlapping port specifier %s", optarg); mode_conflict: die("Port forwarding mode '%s' conflicts with previous mode", optarg); +bind_fail: + die("Failed to bind any port for '-%c %s', exiting", optname, optarg); } /** diff --git a/tcp.c b/tcp.c index f028e01..32ce1e9 100644 --- a/tcp.c +++ b/tcp.c @@ -2916,20 +2916,31 @@ static int tcp_sock_init_af(const struct ctx *c, int af, in_port_t port, * @addr: Pointer to address for binding, NULL if not configured * @ifname: Name of interface to bind to, NULL if not configured * @port: Port, host order + * + * Return: 0 on (partial) success, -1 on (complete) failure */ -void tcp_sock_init(const struct ctx *c, sa_family_t af, const void *addr, - const char *ifname, in_port_t port) +int tcp_sock_init(const struct ctx *c, sa_family_t af, const void *addr, + const char *ifname, in_port_t port) { + int ret = 0; + if (af == AF_UNSPEC && c->ifi4 && c->ifi6) /* Attempt to get a dual stack socket */ if (tcp_sock_init_af(c, AF_UNSPEC, port, addr, ifname) >= 0) - return; + return 0; /* Otherwise create a socket per IP version */ - if ((af == AF_INET || af == AF_UNSPEC) && c->ifi4) - tcp_sock_init_af(c, AF_INET, port, addr, ifname); - if ((af == AF_INET6 || af == AF_UNSPEC) && c->ifi6) - tcp_sock_init_af(c, AF_INET6, port, addr, ifname); + if ((af == AF_INET || af == AF_UNSPEC) && c->ifi4) { + if (tcp_sock_init_af(c, AF_INET, port, addr, ifname) < 0) + ret = -1; + } + + if ((af == AF_INET6 || af == AF_UNSPEC) && c->ifi6) { + if (tcp_sock_init_af(c, AF_INET6, port, addr, ifname) < 0) + ret = -1; + } + + return ret; } /** diff --git a/tcp.h b/tcp.h index 236038f..5527c5b 100644 --- a/tcp.h +++ b/tcp.h @@ -17,8 +17,8 @@ void tcp_sock_handler(struct ctx *c, union epoll_ref ref, uint32_t events, const struct timespec *now); int tcp_tap_handler(struct ctx *c, int af, const void *addr, const struct pool *p, const struct timespec *now); -void tcp_sock_init(const struct ctx *c, sa_family_t af, const void *addr, - const char *ifname, in_port_t port); +int tcp_sock_init(const struct ctx *c, sa_family_t af, const void *addr, + const char *ifname, in_port_t port); int tcp_init(struct ctx *c); void tcp_timer(struct ctx *c, const struct timespec *ts); void tcp_defer_handler(struct ctx *c); diff --git a/udp.c b/udp.c index 2e9b7e6..c913d27 100644 --- a/udp.c +++ b/udp.c @@ -955,12 +955,14 @@ int udp_tap_handler(struct ctx *c, int af, const void *addr, * @addr: Pointer to address for binding, NULL if not configured * @ifname: Name of interface to bind to, NULL if not configured * @port: Port, host order + * + * Return: 0 on (partial) success, -1 on (complete) failure */ -void udp_sock_init(const struct ctx *c, int ns, sa_family_t af, - const void *addr, const char *ifname, in_port_t port) +int udp_sock_init(const struct ctx *c, int ns, sa_family_t af, + const void *addr, const char *ifname, in_port_t port) { union udp_epoll_ref uref = { .u32 = 0 }; - int s; + int s, ret = 0; if (ns) { uref.udp.port = (in_port_t)(port + @@ -989,6 +991,9 @@ void udp_sock_init(const struct ctx *c, int ns, sa_family_t af, ifname, port, uref.u32); udp_splice_ns[V4][port].sock = s; } + + if (s < 0) + ret = -1; } if ((af == AF_INET6 || af == AF_UNSPEC) && c->ifi6) { @@ -1009,7 +1014,12 @@ void udp_sock_init(const struct ctx *c, int ns, sa_family_t af, ifname, port, uref.u32); udp_splice_ns[V6][port].sock = s; } + + if (s < 0) + ret = -1; } + + return ret; } /** diff --git a/udp.h b/udp.h index 68082ea..0e81be8 100644 --- a/udp.h +++ b/udp.h @@ -12,8 +12,8 @@ void udp_sock_handler(struct ctx *c, union epoll_ref ref, uint32_t events, const struct timespec *now); int udp_tap_handler(struct ctx *c, int af, const void *addr, const struct pool *p, const struct timespec *now); -void udp_sock_init(const struct ctx *c, int ns, sa_family_t af, - const void *addr, const char *ifname, in_port_t port); +int udp_sock_init(const struct ctx *c, int ns, sa_family_t af, + const void *addr, const char *ifname, in_port_t port); int udp_init(struct ctx *c); void udp_timer(struct ctx *c, const struct timespec *ts); void udp_update_l2_buf(const unsigned char *eth_d, const unsigned char *eth_s, -- 2.35.1

2 1

[PATCH] dhcp: Fix netmask calculation for option 1 from prefix length
by Stefano Brivio 16 Feb '23

16 Feb '23

Similar to the conf_print() fix from commit 4129764ecaeb ("conf: Fix mask calculation from prefix_len in conf_print()"): to calculate an IPv4 netmask from the prefix length, we need to left shift 32 all-one bits by 32 minus the prefix length -- not by the prefix length itself. Reported-by: Yalan Zhang <yalzhang(a)redhat.com> Fixes: dd09cceaee21 ("Minor improvements to IPv4 netmask handling") Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com> --- dhcp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/dhcp.c b/dhcp.c index 6088886..edab780 100644 --- a/dhcp.c +++ b/dhcp.c @@ -335,7 +335,7 @@ int dhcp(const struct ctx *c, const struct pool *p) m->chaddr[3], m->chaddr[4], m->chaddr[5]); m->yiaddr = c->ip4.addr; - mask.s_addr = htonl(0xffffffff << c->ip4.prefix_len); + mask.s_addr = htonl(0xffffffff << (32 - c->ip4.prefix_len)); memcpy(opts[1].s, &mask, sizeof(mask)); memcpy(opts[3].s, &c->ip4.gw, sizeof(c->ip4.gw)); memcpy(opts[54].s, &c->ip4.gw, sizeof(c->ip4.gw)); -- 2.35.1

2 1

[PATCH] tap: Use single counter for iov elements in tap_send_frames_pasta()
by Stefano Brivio 16 Feb '23

16 Feb '23

David points out that using multiple counters to go over the iov array, namely 'i' and 'iov', makes mistakes easier. We can't just use 'iov', unless we reserve an element with zero iov_len at the end, which isn't really justified. Simply use 'i' to iterate over the array. Link: https://archives.passt.top/passt-dev/Y+mfenvLn3VJ7Dg5@yekko/ Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com> --- tap.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/tap.c b/tap.c index 02da84d..e4c5b5b 100644 --- a/tap.c +++ b/tap.c @@ -316,13 +316,13 @@ static void tap_send_frames_pasta(struct ctx *c, { size_t i; - for (i = 0; i < n; i++, iov++) { - if (write(c->fd_tap, (char *)iov->iov_base, iov->iov_len) < 0) { + for (i = 0; i < n; i++) { + if (write(c->fd_tap, (char *)iov[i].iov_base, + iov[i].iov_len) < 0) { debug("tap write: %s", strerror(errno)); if (errno != EAGAIN && errno != EWOULDBLOCK) tap_handler(c, c->fd_tap, EPOLLERR, NULL); i--; - iov--; } } } -- 2.35.1

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