src: netlink: Remove variable nf_mon_sock.

Remove variable nf_mon_sock of type structure mnl_socket to avoid
duplicity. Instead variable nf_sock of the same type is passed as
argument to netlink_monitor(). Also remove netlink_open_mon_sock()
function definition, which is no longer required.

Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Varsha Rao <rvarsha016@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/include/netlink.h b/include/netlink.h
index 5b43c5c725ef2263d671a3b8029dc1d0c59b1ea6..7865186b627670fd697fcf1f3733b3725f540e32 100644 (file)
--- a/include/netlink.h
+++ b/include/netlink.h
@@ -218,7 +218,8 @@ struct netlink_mon_handler {
        bool                    cache_needed;
 };
 
-extern int netlink_monitor(struct netlink_mon_handler *monhandler);
+extern int netlink_monitor(struct netlink_mon_handler *monhandler,
+                           struct mnl_socket *nf_sock);
 bool netlink_batch_supported(struct mnl_socket *nf_sock);
 
 #endif /* NFTABLES_NETLINK_H */

diff --git a/src/mnl.c b/src/mnl.c
index cf060a40a96f3823c052347ccf79c9f0f89935e5..763931238150735409506f659ead6601565f4ded 100644 (file)
--- a/src/mnl.c
+++ b/src/mnl.c
@@ -1114,30 +1114,41 @@ int mnl_nft_event_listener(struct mnl_socket *nf_sock,
         * message loss due to ENOBUFS.
         */
        unsigned int bufsiz = NFTABLES_NLEVENT_BUFSIZ;
+       int fd = mnl_socket_get_fd(nf_sock);
        char buf[NFT_NLMSG_MAXSIZE];
+       fd_set readfds;
        int ret;
 
-       ret = setsockopt(mnl_socket_get_fd(nf_sock), SOL_SOCKET, SO_RCVBUFFORCE,
-                        &bufsiz, sizeof(socklen_t));
-        if (ret < 0) {
+       ret = setsockopt(fd, SOL_SOCKET, SO_RCVBUFFORCE, &bufsiz,
+                        sizeof(socklen_t));
+       if (ret < 0) {
                /* If this doesn't work, try to reach the system wide maximum
                 * (or whatever the user requested).
                 */
-                ret = setsockopt(mnl_socket_get_fd(nf_sock), SOL_SOCKET,
-                                SO_RCVBUF, &bufsiz, sizeof(socklen_t));
+               ret = setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &bufsiz,
+                                sizeof(socklen_t));
                printf("# Cannot set up netlink socket buffer size to %u bytes, falling back to %u bytes\n",
                       NFTABLES_NLEVENT_BUFSIZ, bufsiz);
        }
 
        while (1) {
-               ret = mnl_socket_recvfrom(nf_sock, buf, sizeof(buf));
-               if (ret < 0) {
-                       if (errno == ENOBUFS) {
-                               printf("# ERROR: We lost some netlink events!\n");
-                               continue;
+               FD_ZERO(&readfds);
+               FD_SET(fd, &readfds);
+
+               ret = select(fd + 1, &readfds, NULL, NULL, NULL);
+               if (ret < 0)
+                       return -1;
+
+               if (FD_ISSET(fd, &readfds)) {
+                       ret = mnl_socket_recvfrom(nf_sock, buf, sizeof(buf));
+                       if (ret < 0) {
+                               if (errno == ENOBUFS) {
+                                       printf("# ERROR: We lost some netlink events!\n");
+                                       continue;
+                               }
+                               fprintf(stdout, "# ERROR: %s\n", strerror(errno));
+                               break;
                        }
-                       fprintf(stdout, "# ERROR: %s\n", strerror(errno));
-                       break;
                }
 
 #ifdef DEBUG

diff --git a/src/netlink.c b/src/netlink.c
index e3c90dac8c7a6126f0ece588e67c6572f29013b9..a3453b96a053aaaab0ad6f799bd1d33497bee99a 100644 (file)
--- a/src/netlink.c
+++ b/src/netlink.c
@@ -39,8 +39,6 @@
 #include <erec.h>
 #include <iface.h>
 
-static struct mnl_socket *nf_mon_sock;
-
 const struct input_descriptor indesc_netlink = {
        .name   = "netlink",
        .type   = INDESC_NETLINK,
@@ -73,8 +71,6 @@ void netlink_close_sock(struct mnl_socket *nf_sock)
 {
        if (nf_sock)
                mnl_socket_close(nf_sock);
-       if (nf_mon_sock)
-               mnl_socket_close(nf_mon_sock);
 }
 
 void netlink_restart(struct mnl_socket *nf_sock)
@@ -88,11 +84,6 @@ void netlink_genid_get(struct mnl_socket *nf_sock)
        mnl_genid_get(nf_sock);
 }
 
-static void netlink_open_mon_sock(void)
-{
-       nf_mon_sock = nfsock_open();
-}
-
 void __noreturn __netlink_abi_error(const char *file, int line,
                                    const char *reason)
 {
@@ -2961,18 +2952,26 @@ static int netlink_events_cb(const struct nlmsghdr *nlh, void *data)
        return ret;
 }
 
-int netlink_monitor(struct netlink_mon_handler *monhandler)
+int netlink_monitor(struct netlink_mon_handler *monhandler,
+                    struct mnl_socket *nf_sock)
 {
-       netlink_open_mon_sock();
+       int group;
+
+       group = NFNLGRP_NFTABLES;
+       if (mnl_socket_setsockopt(nf_sock, NETLINK_ADD_MEMBERSHIP, &group,
+                                 sizeof(int)) < 0)
+               return netlink_io_error(monhandler->ctx, monhandler->loc,
+                                       "Could not bind to netlink socket %s",
+                                       strerror(errno));
 
-       if (mnl_socket_bind(nf_mon_sock, (1 << (NFNLGRP_NFTABLES-1)) |
-                                        (1 << (NFNLGRP_NFTRACE-1)),
-                           MNL_SOCKET_AUTOPID) < 0)
+       group = NFNLGRP_NFTRACE;
+       if (mnl_socket_setsockopt(nf_sock, NETLINK_ADD_MEMBERSHIP, &group,
+                                 sizeof(int)) < 0)
                return netlink_io_error(monhandler->ctx, monhandler->loc,
                                        "Could not bind to netlink socket %s",
                                        strerror(errno));
 
-       return mnl_nft_event_listener(nf_mon_sock, netlink_events_cb,
+       return mnl_nft_event_listener(nf_sock, netlink_events_cb,
                                      monhandler);
 }
 

diff --git a/src/rule.c b/src/rule.c
index 1d89feb9f192459ca76dcf14bca06772bd052470..7f83980c60818a5bd78244819059c2da714b1697 100644 (file)
--- a/src/rule.c
+++ b/src/rule.c
@@ -1659,7 +1659,7 @@ static int do_command_monitor(struct netlink_ctx *ctx, struct cmd *cmd)
        monhandler.ctx = ctx;
        monhandler.loc = &cmd->location;
 
-       return netlink_monitor(&monhandler);
+       return netlink_monitor(&monhandler, ctx->nf_sock);
 }
 
 static int do_command_describe(struct netlink_ctx *ctx, struct cmd *cmd)