network: convert to strnprintf()

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

diff --git a/src/lxc/network.c b/src/lxc/network.c
index 005a21f702c58d3b69da5fa07b8b33bbaeb9084b..d6d625006663a70f238db07814993bab65108d4b 100644 (file)
--- a/src/lxc/network.c
+++ b/src/lxc/network.c
@@ -231,10 +231,10 @@ static int lxc_is_ip_forwarding_enabled(const char *ifname, int family)
        if (family != AF_INET && family != AF_INET6)
                return ret_set_errno(-1, EINVAL);
 
-       ret = snprintf(path, sizeof(path), "/proc/sys/net/%s/conf/%s/%s",
-                      family == AF_INET ? "ipv4" : "ipv6", ifname,
-                      "forwarding");
-       if (ret < 0 || (size_t)ret >= sizeof(path))
+       ret = strnprintf(path, sizeof(path), "/proc/sys/net/%s/conf/%s/%s",
+                        family == AF_INET ? "ipv4" : "ipv6", ifname,
+                        "forwarding");
+       if (ret < 0)
                return ret_set_errno(-1, E2BIG);
 
        return lxc_read_file_expect(path, buf, 1, "1");
@@ -359,8 +359,8 @@ static int setup_veth_native_bridge_vlan(char *veth1, struct lxc_netdev *netdev)
                return 0;
 
        /* Check vlan filtering is enabled on parent bridge. */
-       rc = snprintf(path, sizeof(path), "/sys/class/net/%s/bridge/vlan_filtering", netdev->link);
-       if (rc < 0 || (size_t)rc >= sizeof(path))
+       rc = strnprintf(path, sizeof(path), "/sys/class/net/%s/bridge/vlan_filtering", netdev->link);
+       if (rc < 0)
                return -1;
 
        rc = lxc_read_from_file(path, buf, sizeof(buf));
@@ -382,8 +382,8 @@ static int setup_veth_native_bridge_vlan(char *veth1, struct lxc_netdev *netdev)
                unsigned short default_pvid;
 
                /* Get the bridge's default VLAN PVID. */
-               rc = snprintf(path, sizeof(path), "/sys/class/net/%s/bridge/default_pvid", netdev->link);
-               if (rc < 0 || (size_t)rc >= sizeof(path))
+               rc = strnprintf(path, sizeof(path), "/sys/class/net/%s/bridge/default_pvid", netdev->link);
+               if (rc < 0)
                        return -1;
 
                rc = lxc_read_from_file(path, buf, sizeof(buf));
@@ -443,8 +443,8 @@ static int lxc_ovs_setup_bridge_vlan_exec(void *data)
                char buf[5];
                int rc;
 
-               rc = snprintf(buf, sizeof(buf), "%u", args->vlan_id);
-               if (rc < 0 || (size_t)rc >= sizeof(buf))
+               rc = strnprintf(buf, sizeof(buf), "%u", args->vlan_id);
+               if (rc < 0)
                        return log_error_errno(-1, EINVAL, "Failed to parse ovs bridge vlan \"%d\"", args->vlan_id);
 
                tag = must_concat(NULL, "tag=", buf, (char *)NULL);
@@ -509,8 +509,8 @@ static int setup_veth_ovs_bridge_vlan(char *veth1, struct lxc_netdev *netdev)
                        char buf[5]; /* Sufficient size to fit max VLAN ID (4094) null char. */
                        int rc;
 
-                       rc = snprintf(buf, sizeof(buf), "%u", vlan_id);
-                       if (rc < 0 || (size_t)rc >= sizeof(buf)) {
+                       rc = strnprintf(buf, sizeof(buf), "%u", vlan_id);
+                       if (rc < 0) {
                                free_ovs_veth_vlan_args(&args);
                                return log_error_errno(-1, EINVAL, "Failed to parse tagged vlan \"%u\" for interface \"%s\"", vlan_id, veth1);
                        }
@@ -553,8 +553,8 @@ static int instantiate_veth(struct lxc_handler *handler, struct lxc_netdev *netd
                if (handler->conf->reboot)
                        lxc_netdev_delete_by_name(veth1);
        } else {
-               err = snprintf(veth1buf, sizeof(veth1buf), "vethXXXXXX");
-               if (err < 0 || (size_t)err >= sizeof(veth1buf))
+               err = strnprintf(veth1buf, sizeof(veth1buf), "vethXXXXXX");
+               if (err < 0)
                        return -1;
 
                veth1 = lxc_ifname_alnum_case_sensitive(veth1buf);
@@ -565,8 +565,8 @@ static int instantiate_veth(struct lxc_handler *handler, struct lxc_netdev *netd
                memcpy(netdev->priv.veth_attr.veth1, veth1, IFNAMSIZ);
        }
 
-       err = snprintf(veth2buf, sizeof(veth2buf), "vethXXXXXX");
-       if (err < 0 || (size_t)err >= sizeof(veth2buf))
+       err = strnprintf(veth2buf, sizeof(veth2buf), "vethXXXXXX");
+       if (err < 0)
                return -1;
 
        veth2 = lxc_ifname_alnum_case_sensitive(veth2buf);
@@ -781,8 +781,8 @@ static int instantiate_macvlan(struct lxc_handler *handler, struct lxc_netdev *n
                return -1;
        }
 
-       err = snprintf(peer, sizeof(peer), "mcXXXXXX");
-       if (err < 0 || (size_t)err >= sizeof(peer))
+       err = strnprintf(peer, sizeof(peer), "mcXXXXXX");
+       if (err < 0)
                return -1;
 
        if (!lxc_ifname_alnum_case_sensitive(peer))
@@ -931,8 +931,8 @@ static int instantiate_ipvlan(struct lxc_handler *handler, struct lxc_netdev *ne
                return -1;
        }
 
-       err = snprintf(peer, sizeof(peer), "ipXXXXXX");
-       if (err < 0 || (size_t)err >= sizeof(peer))
+       err = strnprintf(peer, sizeof(peer), "ipXXXXXX");
+       if (err < 0)
                return -1;
 
        if (!lxc_ifname_alnum_case_sensitive(peer))
@@ -1006,9 +1006,9 @@ static int instantiate_vlan(struct lxc_handler *handler, struct lxc_netdev *netd
                return -1;
        }
 
-       err = snprintf(peer, sizeof(peer), "vlan%d-%d",
-                      netdev->priv.vlan_attr.vid, vlan_cntr++);
-       if (err < 0 || (size_t)err >= sizeof(peer))
+       err = strnprintf(peer, sizeof(peer), "vlan%d-%d",
+                        netdev->priv.vlan_attr.vid, vlan_cntr++);
+       if (err < 0)
                return -1;
 
        err = lxc_vlan_create(netdev->link, peer, netdev->priv.vlan_attr.vid);
@@ -1489,8 +1489,8 @@ char *is_wlan(const char *ifname)
 
        len = strlen(ifname) + strlen(PHYSNAME) - 1;
        path = must_realloc(NULL, len + 1);
-       ret = snprintf(path, len, PHYSNAME, ifname);
-       if (ret < 0 || (size_t)ret >= len)
+       ret = strnprintf(path, len, PHYSNAME, ifname);
+       if (ret < 0)
                return NULL;
 
        f = fopen(path, "re");
@@ -2217,9 +2217,10 @@ static int ip_forwarding_set(const char *ifname, int family, int flag)
        if (family != AF_INET && family != AF_INET6)
                return -EINVAL;
 
-       ret = snprintf(path, sizeof(path), "/proc/sys/net/%s/conf/%s/%s",
-                      family == AF_INET ? "ipv4" : "ipv6", ifname, "forwarding");
-       if (ret < 0 || (size_t)ret >= sizeof(path))
+       ret = strnprintf(path, sizeof(path), "/proc/sys/net/%s/conf/%s/%s",
+                        family == AF_INET ? "ipv4" : "ipv6", ifname,
+                        "forwarding");
+       if (ret < 0)
                return -E2BIG;
 
        return proc_sys_net_write(path, flag ? "1" : "0");
@@ -2243,10 +2244,10 @@ static int neigh_proxy_set(const char *ifname, int family, int flag)
        if (family != AF_INET && family != AF_INET6)
                return -EINVAL;
 
-       ret = snprintf(path, sizeof(path), "/proc/sys/net/%s/conf/%s/%s",
-                      family == AF_INET ? "ipv4" : "ipv6", ifname,
-                      family == AF_INET ? "proxy_arp" : "proxy_ndp");
-       if (ret < 0 || (size_t)ret >= sizeof(path))
+       ret = strnprintf(path, sizeof(path), "/proc/sys/net/%s/conf/%s/%s",
+                        family == AF_INET ? "ipv4" : "ipv6", ifname,
+                        family == AF_INET ? "proxy_arp" : "proxy_ndp");
+       if (ret < 0)
                return -E2BIG;
 
        return proc_sys_net_write(path, flag ? "1" : "0");
@@ -2261,10 +2262,10 @@ static int lxc_is_ip_neigh_proxy_enabled(const char *ifname, int family)
        if (family != AF_INET && family != AF_INET6)
                return ret_set_errno(-1, EINVAL);
 
-       ret = snprintf(path, sizeof(path), "/proc/sys/net/%s/conf/%s/%s",
-                      family == AF_INET ? "ipv4" : "ipv6", ifname,
-                      family == AF_INET ? "proxy_arp" : "proxy_ndp");
-       if (ret < 0 || (size_t)ret >= sizeof(path))
+       ret = strnprintf(path, sizeof(path), "/proc/sys/net/%s/conf/%s/%s",
+                        family == AF_INET ? "ipv4" : "ipv6", ifname,
+                        family == AF_INET ? "proxy_arp" : "proxy_ndp");
+       if (ret < 0)
                return ret_set_errno(-1, E2BIG);
 
        return lxc_read_file_expect(path, buf, 1, "1");
@@ -2629,9 +2630,9 @@ bool is_ovs_bridge(const char *bridge)
        struct stat sb;
        char brdirname[22 + IFNAMSIZ + 1] = {0};
 
-       ret = snprintf(brdirname, 22 + IFNAMSIZ + 1, "/sys/class/net/%s/bridge",
-                      bridge);
-       if (ret < 0 || (size_t)ret >= 22 + IFNAMSIZ + 1)
+       ret = strnprintf(brdirname, 22 + IFNAMSIZ + 1,
+                        "/sys/class/net/%s/bridge", bridge);
+       if (ret < 0)
                return false;
 
        ret = stat(brdirname, &sb);
@@ -2795,28 +2796,24 @@ char *lxc_ifname_alnum_case_sensitive(char *template)
 
 int setup_private_host_hw_addr(char *veth1)
 {
-       int err, sockfd;
+       __do_close int sockfd = -EBADF;
+       int err;
        struct ifreq ifr;
 
        sockfd = socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
        if (sockfd < 0)
                return -errno;
 
-       err = snprintf((char *)ifr.ifr_name, IFNAMSIZ, "%s", veth1);
-       if (err < 0 || (size_t)err >= IFNAMSIZ) {
-               close(sockfd);
-               return -E2BIG;
-       }
+       err = strnprintf((char *)ifr.ifr_name, IFNAMSIZ, "%s", veth1);
+       if (err < 0)
+               return err;
 
        err = ioctl(sockfd, SIOCGIFHWADDR, &ifr);
-       if (err < 0) {
-               close(sockfd);
+       if (err < 0)
                return -errno;
-       }
 
        ifr.ifr_hwaddr.sa_data[0] = 0xfe;
        err = ioctl(sockfd, SIOCSIFHWADDR, &ifr);
-       close(sockfd);
        if (err < 0)
                return -errno;
 
@@ -2910,8 +2907,8 @@ static int lxc_create_network_unpriv_exec(const char *lxcpath, const char *lxcna
                        _exit(EXIT_FAILURE);
                }
 
-               ret = snprintf(pidstr, sizeof(pidstr), "%d", pid);
-               if (ret < 0 || ret >= sizeof(pidstr))
+               ret = strnprintf(pidstr, sizeof(pidstr), "%d", pid);
+               if (ret < 0)
                        _exit(EXIT_FAILURE);
                pidstr[sizeof(pidstr) - 1] = '\0';
 
@@ -3108,9 +3105,9 @@ static bool lxc_delete_network_unpriv(struct lxc_handler *handler)
        if (handler->nsfd[LXC_NS_NET] < 0)
                return log_debug(false, "Cannot not guarantee safe deletion of network devices. Manual cleanup maybe needed");
 
-       ret = snprintf(netns_path, sizeof(netns_path), "/proc/%d/fd/%d",
-                      lxc_raw_getpid(), handler->nsfd[LXC_NS_NET]);
-       if (ret < 0 || ret >= sizeof(netns_path))
+       ret = strnprintf(netns_path, sizeof(netns_path), "/proc/%d/fd/%d",
+                        lxc_raw_getpid(), handler->nsfd[LXC_NS_NET]);
+       if (ret < 0)
                return false;
 
        lxc_list_for_each(iterator, network) {