Merge branch 'master' into net-next

[mirror_iproute2.git] / lib / libnetlink.c

diff --git a/lib/libnetlink.c b/lib/libnetlink.c
index 424a5b6ffe8f02ce125ffcdab5825529781e3e24..46cac34c7581e45c038a3e37d71f2eeb8dd962b7 100644 (file)
--- a/lib/libnetlink.c
+++ b/lib/libnetlink.c
@@ -29,6 +29,10 @@
 #define SOL_NETLINK 270
 #endif
 
+#ifndef MIN
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+#endif
+
 int rcvbuf = 1024 * 1024;
 
 void rtnl_close(struct rtnl_handle *rth)
@@ -304,8 +308,8 @@ int rtnl_dump_filter(struct rtnl_handle *rth,
        return rtnl_dump_filter_l(rth, a);
 }
 
-int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
-             unsigned groups, struct nlmsghdr *answer)
+int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
+             struct nlmsghdr *answer, size_t len)
 {
        int status;
        unsigned seq;
@@ -321,12 +325,10 @@ int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
                .msg_iov = &iov,
                .msg_iovlen = 1,
        };
-       char   buf[16384];
+       char   buf[32768];
 
        memset(&nladdr, 0, sizeof(nladdr));
        nladdr.nl_family = AF_NETLINK;
-       nladdr.nl_pid = peer;
-       nladdr.nl_groups = groups;
 
        n->nlmsg_seq = seq = ++rtnl->seq;
 
@@ -334,7 +336,6 @@ int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
                n->nlmsg_flags |= NLM_F_ACK;
 
        status = sendmsg(rtnl->fd, &msg, 0);
-
        if (status < 0) {
                perror("Cannot talk to rtnetlink");
                return -1;
@@ -343,7 +344,6 @@ int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
        memset(buf,0,sizeof(buf));
 
        iov.iov_base = buf;
-
        while (1) {
                iov.iov_len = sizeof(buf);
                status = recvmsg(rtnl->fd, &msg, 0);
@@ -376,7 +376,7 @@ int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
                                exit(1);
                        }
 
-                       if (nladdr.nl_pid != peer ||
+                       if (nladdr.nl_pid != 0 ||
                            h->nlmsg_pid != rtnl->local.nl_pid ||
                            h->nlmsg_seq != seq) {
                                /* Don't forget to skip that message. */
@@ -389,20 +389,22 @@ int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
                                struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
                                if (l < sizeof(struct nlmsgerr)) {
                                        fprintf(stderr, "ERROR truncated\n");
-                               } else {
-                                       if (!err->error) {
-                                               if (answer)
-                                                       memcpy(answer, h, h->nlmsg_len);
-                                               return 0;
-                                       }
-
-                                       fprintf(stderr, "RTNETLINK answers: %s\n", strerror(-err->error));
-                                       errno = -err->error;
+                               } else if (!err->error) {
+                                       if (answer)
+                                               memcpy(answer, h,
+                                                      MIN(len, h->nlmsg_len));
+                                       return 0;
                                }
+
+                               fprintf(stderr, "RTNETLINK answers: %s\n",
+                                       strerror(-err->error));
+                               errno = -err->error;
                                return -1;
                        }
+
                        if (answer) {
-                               memcpy(answer, h, h->nlmsg_len);
+                               memcpy(answer, h,
+                                      MIN(len, h->nlmsg_len));
                                return 0;
                        }
 
@@ -411,10 +413,12 @@ int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
                        status -= NLMSG_ALIGN(len);
                        h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
                }
+
                if (msg.msg_flags & MSG_TRUNC) {
                        fprintf(stderr, "Message truncated\n");
                        continue;
                }
+
                if (status) {
                        fprintf(stderr, "!!!Remnant of size %d\n", status);
                        exit(1);