sd-rtnl: never set serial to 0

[elogind.git] / src / libsystemd / sd-rtnl / sd-rtnl.c

diff --git a/src/libsystemd/sd-rtnl/sd-rtnl.c b/src/libsystemd/sd-rtnl/sd-rtnl.c
index 7f1ec308a8e79a4d739d76684db3b5c8751f193c..f483af991bc2f8e46861c77641703047d06249bb 100644 (file)
--- a/src/libsystemd/sd-rtnl/sd-rtnl.c
+++ b/src/libsystemd/sd-rtnl/sd-rtnl.c
@@ -61,6 +61,36 @@ static int sd_rtnl_new(sd_rtnl **ret) {
                             sizeof(struct nlmsghdr), sizeof(uint8_t)))
                 return -ENOMEM;
 
+        /* Change notification responses have sequence 0, so we must
+         * start our request sequence numbers at 1, or we may confuse our
+         * responses with notifications from the kernel */
+        rtnl->serial = 1;
+
+        *ret = rtnl;
+        rtnl = NULL;
+
+        return 0;
+}
+
+int sd_rtnl_new_from_netlink(sd_rtnl **ret, int fd) {
+        _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL;
+        socklen_t addrlen;
+        int r;
+
+        assert_return(ret, -EINVAL);
+
+        r = sd_rtnl_new(&rtnl);
+        if (r < 0)
+                return r;
+
+        addrlen = sizeof(rtnl->sockaddr);
+
+        r = getsockname(fd, &rtnl->sockaddr.sa, &addrlen);
+        if (r < 0)
+                return -errno;
+
+        rtnl->fd = fd;
+
         *ret = rtnl;
         rtnl = NULL;
 
@@ -121,12 +151,13 @@ static int rtnl_open_fd_ap(sd_rtnl **ret, int fd, unsigned n_groups, va_list ap)
         addrlen = sizeof(rtnl->sockaddr);
 
         r = bind(fd, &rtnl->sockaddr.sa, addrlen);
-        if (r < 0)
+        /* ignore EINVAL to allow opening an already bound socket */
+        if (r < 0 && errno != EINVAL)
                 return -errno;
 
         r = getsockname(fd, &rtnl->sockaddr.sa, &addrlen);
         if (r < 0)
-                return r;
+                return -errno;
 
         rtnl->fd = fd;
 
@@ -231,7 +262,7 @@ static void rtnl_seal_message(sd_rtnl *rtnl, sd_rtnl_message *m) {
         assert(m);
         assert(m->hdr);
 
-        m->hdr->nlmsg_seq = rtnl->serial++;
+        m->hdr->nlmsg_seq = rtnl->serial++ ? : rtnl->serial++;
 
         rtnl_message_seal(m);
 
@@ -967,7 +998,7 @@ int sd_rtnl_add_match(sd_rtnl *rtnl,
         assert_return(!rtnl_pid_changed(rtnl), -ECHILD);
         assert_return(rtnl_message_type_is_link(type) ||
                       rtnl_message_type_is_addr(type) ||
-                      rtnl_message_type_is_route(type), -ENOTSUP);
+                      rtnl_message_type_is_route(type), -EOPNOTSUPP);
 
         c = new0(struct match_callback, 1);
         if (!c)