MINOR: tcp: When binding socket, attempt to reuse one from the old proc.
Try to reuse any socket from the old process, provided by the "-x" flag,
before binding a new one, assuming it is compatible.
"Compatible" here means same address and port, same namspace if any,
same interface if any, and that the following flags are the same :
LI_O_FOREIGN, LI_O_V6ONLY and LI_O_V4V6.
Also change tcp_bind_listener() to always enable/disable socket options,
instead of just doing so if it is in the configuration file, as the option
may have been removed, ie TCP_FASTOPEN may have been set in the old process,
and removed from the new configuration, so we have to disable it.
diff --git a/src/proto_tcp.c b/src/proto_tcp.c
index 5e12b99..57d6fc1 100644
--- a/src/proto_tcp.c
+++ b/src/proto_tcp.c
@@ -110,6 +110,12 @@
.nb_listeners = 0,
};
+/* Default TCP parameters, got by opening a temporary TCP socket. */
+#ifdef TCP_MAXSEG
+static int default_tcp_maxseg = -1;
+static int default_tcp6_maxseg = -1;
+#endif
+
/* Binds ipv4/ipv6 address <local> to socket <fd>, unless <flags> is set, in which
* case we try to bind <remote>. <flags> is a 2-bit field consisting of :
* - 0 : ignore remote address (may even be a NULL pointer)
@@ -731,6 +737,83 @@
return 0;
}
+/* XXX: Should probably be elsewhere */
+static int compare_sockaddr(struct sockaddr_storage *a, struct sockaddr_storage *b)
+{
+ if (a->ss_family != b->ss_family) {
+ return (-1);
+ }
+ switch (a->ss_family) {
+ case AF_INET:
+ {
+ struct sockaddr_in *a4 = (void *)a, *b4 = (void *)b;
+ if (a4->sin_port != b4->sin_port)
+ return (-1);
+ return (memcmp(&a4->sin_addr, &b4->sin_addr,
+ sizeof(a4->sin_addr)));
+ }
+ case AF_INET6:
+ {
+ struct sockaddr_in6 *a6 = (void *)a, *b6 = (void *)b;
+ if (a6->sin6_port != b6->sin6_port)
+ return (-1);
+ return (memcmp(&a6->sin6_addr, &b6->sin6_addr,
+ sizeof(a6->sin6_addr)));
+ }
+ default:
+ return (-1);
+ }
+
+}
+
+#define LI_MANDATORY_FLAGS (LI_O_FOREIGN | LI_O_V6ONLY | LI_O_V4V6)
+/* When binding the listeners, check if a socket has been sent to us by the
+ * previous process that we could reuse, instead of creating a new one.
+ */
+static int tcp_find_compatible_fd(struct listener *l)
+{
+ struct xfer_sock_list *xfer_sock = xfer_sock_list;
+ int ret = -1;
+
+ while (xfer_sock) {
+ if (!compare_sockaddr(&xfer_sock->addr, &l->addr)) {
+ if ((l->interface == NULL && xfer_sock->iface == NULL) ||
+ (l->interface != NULL && xfer_sock->iface != NULL &&
+ !strcmp(l->interface, xfer_sock->iface))) {
+ if ((l->options & LI_MANDATORY_FLAGS) ==
+ (xfer_sock->options & LI_MANDATORY_FLAGS)) {
+ if ((xfer_sock->namespace == NULL &&
+ l->netns == NULL)
+#ifdef CONFIG_HAP_NS
+ || (xfer_sock->namespace != NULL &&
+ l->netns != NULL &&
+ !strcmp(xfer_sock->namespace,
+ l->netns->node.key))
+#endif
+ ) {
+ break;
+ }
+
+ }
+ }
+ }
+ xfer_sock = xfer_sock->next;
+ }
+ if (xfer_sock != NULL) {
+ ret = xfer_sock->fd;
+ if (xfer_sock == xfer_sock_list)
+ xfer_sock_list = xfer_sock->next;
+ if (xfer_sock->prev)
+ xfer_sock->prev->next = xfer_sock->next;
+ if (xfer_sock->next)
+ xfer_sock->next->prev = xfer_sock->prev;
+ free(xfer_sock->iface);
+ free(xfer_sock->namespace);
+ free(xfer_sock);
+ }
+ return ret;
+}
+#undef L1_MANDATORY_FLAGS
/* This function tries to bind a TCPv4/v6 listener. It may return a warning or
* an error message in <errmsg> if the message is at most <errlen> bytes long
@@ -752,6 +835,36 @@
int ext, ready;
socklen_t ready_len;
const char *msg = NULL;
+#ifdef TCP_MAXSEG
+
+ /* Create a temporary TCP socket to get default parameters we can't
+ * guess.
+ * */
+ ready_len = sizeof(default_tcp_maxseg);
+ if (default_tcp_maxseg == -1) {
+ default_tcp_maxseg = -2;
+ fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+ if (fd < 0)
+ Warning("Failed to create a temporary socket!\n");
+ else {
+ if (getsockopt(fd, IPPROTO_TCP, TCP_MAXSEG, &default_tcp_maxseg,
+ &ready_len) == -1)
+ Warning("Failed to get the default value of TCP_MAXSEG\n");
+ }
+ close(fd);
+ }
+ if (default_tcp6_maxseg == -1) {
+ default_tcp6_maxseg = -2;
+ fd = socket(AF_INET6, SOCK_STREAM, IPPROTO_TCP);
+ if (fd >= 0) {
+ if (getsockopt(fd, IPPROTO_TCP, TCP_MAXSEG, &default_tcp6_maxseg,
+ &ready_len) == -1)
+ Warning("Failed ot get the default value of TCP_MAXSEG for IPv6\n");
+ close(fd);
+ }
+ }
+#endif
+
/* ensure we never return garbage */
if (errlen)
@@ -762,6 +875,9 @@
err = ERR_NONE;
+ if (listener->fd == -1)
+ listener->fd = tcp_find_compatible_fd(listener);
+
/* if the listener already has an fd assigned, then we were offered the
* fd by an external process (most likely the parent), and we don't want
* to create a new socket. However we still want to set a few flags on
@@ -800,6 +916,17 @@
if (listener->options & LI_O_NOLINGER)
setsockopt(fd, SOL_SOCKET, SO_LINGER, &nolinger, sizeof(struct linger));
+ else {
+ struct linger tmplinger;
+ socklen_t len = sizeof(tmplinger);
+ if (getsockopt(fd, SOL_SOCKET, SO_LINGER, &tmplinger, &len) == 0 &&
+ (tmplinger.l_onoff == 1 || tmplinger.l_linger == 0)) {
+ tmplinger.l_onoff = 0;
+ tmplinger.l_linger = 0;
+ setsockopt(fd, SOL_SOCKET, SO_LINGER, &tmplinger,
+ sizeof(tmplinger));
+ }
+ }
#ifdef SO_REUSEPORT
/* OpenBSD and Linux 3.9 support this. As it's present in old libc versions of
@@ -869,6 +996,23 @@
msg = "cannot set MSS";
err |= ERR_WARN;
}
+ } else if (ext) {
+ int tmpmaxseg = -1;
+ int defaultmss;
+ socklen_t len = sizeof(tmpmaxseg);
+
+ if (listener->addr.ss_family == AF_INET)
+ defaultmss = default_tcp_maxseg;
+ else
+ defaultmss = default_tcp6_maxseg;
+
+ getsockopt(fd, IPPROTO_TCP, TCP_MAXSEG, &tmpmaxseg, &len);
+ if (tmpmaxseg != defaultmss && setsockopt(fd, IPPROTO_TCP,
+ TCP_MAXSEG, &defaultmss,
+ sizeof(defaultmss)) == -1) {
+ msg = "cannot set MSS";
+ err |= ERR_WARN;
+ }
}
#endif
#if defined(TCP_USER_TIMEOUT)
@@ -878,7 +1022,9 @@
msg = "cannot set TCP User Timeout";
err |= ERR_WARN;
}
- }
+ } else
+ setsockopt(fd, IPPROTO_TCP, TCP_USER_TIMEOUT, &zero,
+ sizeof(zero));
#endif
#if defined(TCP_DEFER_ACCEPT)
if (listener->options & LI_O_DEF_ACCEPT) {
@@ -888,7 +1034,9 @@
msg = "cannot enable DEFER_ACCEPT";
err |= ERR_WARN;
}
- }
+ } else
+ setsockopt(fd, IPPROTO_TCP, TCP_DEFER_ACCEPT, &zero,
+ sizeof(zero));
#endif
#if defined(TCP_FASTOPEN)
if (listener->options & LI_O_TCP_FO) {
@@ -898,6 +1046,21 @@
msg = "cannot enable TCP_FASTOPEN";
err |= ERR_WARN;
}
+ } else {
+ socklen_t len;
+ int qlen;
+ len = sizeof(qlen);
+ /* Only disable fast open if it was enabled, we don't want
+ * the kernel to create a fast open queue if there's none.
+ */
+ if (getsockopt(fd, IPPROTO_TCP, TCP_FASTOPEN, &qlen, &len) == 0 &&
+ qlen != 0) {
+ if (setsockopt(fd, IPPROTO_TCP, TCP_FASTOPEN, &zero,
+ sizeof(zero)) == -1) {
+ msg = "cannot disable TCP_FASTOPEN";
+ err |= ERR_WARN;
+ }
+ }
}
#endif
#if defined(IPV6_V6ONLY)
@@ -928,6 +1091,8 @@
#if defined(TCP_QUICKACK)
if (listener->options & LI_O_NOQUICKACK)
setsockopt(fd, IPPROTO_TCP, TCP_QUICKACK, &zero, sizeof(zero));
+ else
+ setsockopt(fd, IPPROTO_TCP, TCP_QUICKACK, &one, sizeof(one));
#endif
/* the socket is ready */