network: minor tweaks

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/src/lxc/network.c b/src/lxc/network.c
index 8a7613f4d69d5bee12de29a0a496e89d15d3a739..72a3d6b7ab544f4bcc53c9a3ba6ab1a9a66710d1 100644 (file)
--- a/src/lxc/network.c
+++ b/src/lxc/network.c
@@ -3171,6 +3171,7 @@ int addattr(struct nlmsghdr *n, size_t maxlen, int type, const void *data, size_
        int len = RTA_LENGTH(alen);
        struct rtattr *rta;
 
+       errno = EMSGSIZE;
        if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen)
                return -1;
 
@@ -3204,8 +3205,8 @@ int lxc_netns_set_nsid(int fd)
        struct nlmsghdr *hdr;
        struct rtgenmsg *msg;
        int saved_errno;
-       __s32 ns_id = -1;
-       __u32 netns_fd = fd;
+       const __s32 ns_id = -1;
+       const __u32 netns_fd = fd;
 
        ret = netlink_open(&nlh, NETLINK_ROUTE);
        if (ret < 0)
@@ -3222,17 +3223,22 @@ int lxc_netns_set_nsid(int fd)
        hdr->nlmsg_seq = RTM_NEWNSID;
        msg->rtgen_family = AF_UNSPEC;
 
-       addattr(hdr, 1024, __LXC_NETNSA_FD, &netns_fd, sizeof(netns_fd));
-       addattr(hdr, 1024, __LXC_NETNSA_NSID, &ns_id, sizeof(ns_id));
+       ret = addattr(hdr, 1024, __LXC_NETNSA_FD, &netns_fd, sizeof(netns_fd));
+       if (ret < 0)
+               goto on_error;
+
+       ret = addattr(hdr, 1024, __LXC_NETNSA_NSID, &ns_id, sizeof(ns_id));
+       if (ret < 0)
+               goto on_error;
 
        ret = __netlink_transaction(&nlh, hdr, hdr);
+
+on_error:
        saved_errno = errno;
        netlink_close(&nlh);
        errno = saved_errno;
-       if (ret < 0)
-               return -1;
 
-       return 0;
+       return ret;
 }
 
 static int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len)
@@ -3267,7 +3273,8 @@ int lxc_netns_get_nsid(int fd)
        int ret;
        ssize_t len;
        char buf[NLMSG_ALIGN(sizeof(struct nlmsghdr)) +
-                NLMSG_ALIGN(sizeof(struct rtgenmsg)) + NLMSG_ALIGN(1024)];
+                NLMSG_ALIGN(sizeof(struct rtgenmsg)) +
+                NLMSG_ALIGN(1024)];
        struct rtattr *tb[__LXC_NETNSA_MAX + 1];
        struct nl_handler nlh;
        struct nlmsghdr *hdr;
@@ -3290,15 +3297,17 @@ int lxc_netns_get_nsid(int fd)
        hdr->nlmsg_seq = RTM_GETNSID;
        msg->rtgen_family = AF_UNSPEC;
 
-       addattr(hdr, 1024, __LXC_NETNSA_FD, &netns_fd, sizeof(netns_fd));
+       ret = addattr(hdr, 1024, __LXC_NETNSA_FD, &netns_fd, sizeof(netns_fd));
+       if (ret == 0)
+               ret = __netlink_transaction(&nlh, hdr, hdr);
 
-       ret = __netlink_transaction(&nlh, hdr, hdr);
        saved_errno = errno;
        netlink_close(&nlh);
        errno = saved_errno;
        if (ret < 0)
                return -1;
 
+       errno = EINVAL;
        msg = NLMSG_DATA(hdr);
        len = hdr->nlmsg_len - NLMSG_SPACE(sizeof(*msg));
        if (len < 0)