tcpi_bytes_acked and tcpi_min_rtt are only available on recent
kernel versions: provide fall-back paths (incurring some grade of
performance penalty).
Support for getrandom() was introduced in Linux 3.17 and glibc 2.25:
provide an alternate mechanism for that as well, reading from
/dev/random.
Also check if NETLINK_GET_STRICT_CHK is defined before using it:
it's not strictly needed, we'll filter out irrelevant results from
netlink anyway.
Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com>
---
Makefile | 15 +++++++++++++++
netlink.c | 9 +++++++--
tcp.c | 36 ++++++++++++++++++++++++++++++++++++
3 files changed, 58 insertions(+), 2 deletions(-)
diff --git a/Makefile b/Makefile
index 4647210..443c39d 100644
--- a/Makefile
+++ b/Makefile
@@ -45,6 +45,21 @@ ifeq ($(shell printf "$(C)" | $(CC) -S -xc - -o -
>/dev/null 2>&1; echo $$?),0)
CFLAGS += -DHAS_SND_WND
endif
+C := \#include <linux/tcp.h>\nstruct tcp_info x = { .tcpi_bytes_acked = 0 };
+ifeq ($(shell printf "$(C)" | $(CC) -S -xc - -o - >/dev/null 2>&1;
echo $$?),0)
+ CFLAGS += -DHAS_BYTES_ACKED
+endif
+
+C := \#include <linux/tcp.h>\nstruct tcp_info x = { .tcpi_min_rtt = 0 };
+ifeq ($(shell printf "$(C)" | $(CC) -S -xc - -o - >/dev/null 2>&1;
echo $$?),0)
+ CFLAGS += -DHAS_MIN_RTT
+endif
+
+C := \#include <sys/random.h>\nint main(){int a=getrandom(0, 0, 0);}
+ifeq ($(shell printf "$(C)" | $(CC) -S -xc - -o - >/dev/null 2>&1;
echo $$?),0)
+ CFLAGS += -DHAS_GETRANDOM
+endif
+
prefix ?= /usr/local
all: passt pasta passt4netns qrap
diff --git a/netlink.c b/netlink.c
index 0948f45..3ba5f05 100644
--- a/netlink.c
+++ b/netlink.c
@@ -46,7 +46,10 @@ static int nl_seq;
static int nl_sock_init_do(void *arg)
{
struct sockaddr_nl addr = { .nl_family = AF_NETLINK, };
- int *s = &nl_sock, v = 1;
+ int *s = &nl_sock;
+#ifdef NETLINK_GET_STRICT_CHK
+ int y = 1;
+#endif
ns:
if (((*s) = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE)) < 0 ||
@@ -56,7 +59,9 @@ ns:
if (*s == -1 || !arg || s == &nl_sock_ns)
return 0;
- setsockopt(*s, SOL_NETLINK, NETLINK_GET_STRICT_CHK, &v, sizeof(v));
+#ifdef NETLINK_GET_STRICT_CHK
+ setsockopt(*s, SOL_NETLINK, NETLINK_GET_STRICT_CHK, &y, sizeof(y));
+#endif
ns_enter((struct ctx *)arg);
s = &nl_sock_ns;
diff --git a/tcp.c b/tcp.c
index 96d462f..839bf30 100644
--- a/tcp.c
+++ b/tcp.c
@@ -321,7 +321,9 @@
#include <stddef.h>
#include <string.h>
#include <sys/epoll.h>
+#ifdef HAS_GETRANDOM
#include <sys/random.h>
+#endif
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/uio.h>
@@ -760,6 +762,7 @@ static int tcp_rtt_dst_low(struct tcp_tap_conn *conn)
*/
static void tcp_rtt_dst_check(struct tcp_tap_conn *conn, struct tcp_info *tinfo)
{
+#ifdef HAS_MIN_RTT
int i, hole = -1;
if (!tinfo->tcpi_min_rtt ||
@@ -777,6 +780,10 @@ static void tcp_rtt_dst_check(struct tcp_tap_conn *conn, struct
tcp_info *tinfo)
if (hole == LOW_RTT_TABLE_SIZE)
hole = 0;
memcpy(low_rtt_dst + hole, &in6addr_any, sizeof(conn->a.a6));
+#else
+ (void)conn;
+ (void)tinfo;
+#endif /* HAS_MIN_RTT */
}
/**
@@ -1552,6 +1559,13 @@ static int tcp_update_seqack_wnd(struct ctx *c, struct tcp_tap_conn
*conn,
struct tcp_info tinfo_new;
int s = conn->sock;
+#ifndef HAS_BYTES_ACKED
+ (void)flags;
+
+ conn->seq_ack_to_tap = conn->seq_from_tap;
+ if (SEQ_LT(conn->seq_ack_to_tap, prev_ack_to_tap))
+ conn->seq_ack_to_tap = prev_ack_to_tap;
+#else
if (conn->state > ESTABLISHED || (flags & (DUP_ACK | FORCE_ACK)) ||
conn->local || tcp_rtt_dst_low(conn) ||
conn->snd_buf < SNDBUF_SMALL) {
@@ -1569,6 +1583,7 @@ static int tcp_update_seqack_wnd(struct ctx *c, struct tcp_tap_conn
*conn,
if (SEQ_LT(conn->seq_ack_to_tap, prev_ack_to_tap))
conn->seq_ack_to_tap = prev_ack_to_tap;
}
+#endif /* !HAS_BYTES_ACKED */
if (!KERNEL_REPORTS_SND_WND(c)) {
tcp_get_sndbuf(conn);
@@ -3586,9 +3601,30 @@ int tcp_sock_init(struct ctx *c, struct timespec *now)
{
struct tcp_sock_refill_arg refill_arg = { c, 0 };
int i, port;
+#ifndef HAS_GETRANDOM
+ int dev_random = open("/dev/random", O_RDONLY);
+ unsigned int random_read = 0;
+
+ while (dev_random && random_read < sizeof(c->tcp.hash_secret)) {
+ int ret = read(dev_random,
+ (uint8_t *)&c->tcp.hash_secret + random_read,
+ sizeof(c->tcp.hash_secret) - random_read);
+ if (ret == -1 && errno == EINTR)
+ continue;
+
+ if (ret <= 0)
+ break;
+
+ random_read += ret;
+ }
+ if (dev_random >= 0)
+ close(dev_random);
+ if (random_read < sizeof(c->tcp.hash_secret)) {
+#else
if (getrandom(&c->tcp.hash_secret, sizeof(c->tcp.hash_secret),
GRND_RANDOM) < 0) {
+#endif /* !HAS_GETRANDOM */
perror("TCP initial sequence getrandom");
exit(EXIT_FAILURE);
}
--
2.33.0