X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=avahi-autoipd%2Fiface-linux.c;h=fc27829d43c9fbd989f7142d27fa90b9b12292a0;hb=22d4df25cb5093a878dca5132b316c27ba47bd83;hp=2ad8a61ab53b0992205aab915a4d7db29a58c0cf;hpb=ef98a3da45ebbc3bbf9601a3eef1a4eb65fb9a84;p=catta

diff --git a/avahi-autoipd/iface-linux.c b/avahi-autoipd/iface-linux.c
index 2ad8a61..fc27829 100644
--- a/avahi-autoipd/iface-linux.c
+++ b/avahi-autoipd/iface-linux.c
@@ -1,18 +1,16 @@
-/* $Id$ */
-
 /***
   This file is part of avahi.
- 
+
   avahi is free software; you can redistribute it and/or modify it
   under the terms of the GNU Lesser General Public License as
   published by the Free Software Foundation; either version 2.1 of the
   License, or (at your option) any later version.
- 
+
   avahi is distributed in the hope that it will be useful, but WITHOUT
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
   Public License for more details.
- 
+
   You should have received a copy of the GNU Lesser General Public
   License along with avahi; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
@@ -66,7 +64,8 @@ AVAHI_LLIST_HEAD(Address, addresses) = NULL;
 
 int iface_init(int i) {
     struct sockaddr_nl addr;
-    
+    int on = 1;
+
     if ((fd = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE)) < 0) {
         daemon_log(LOG_ERR, "socket(PF_NETLINK): %s", strerror(errno));
         goto fail;
@@ -82,16 +81,21 @@ int iface_init(int i) {
         goto fail;
     }
 
+    if (setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on)) < 0) {
+        daemon_log(LOG_ERR, "SO_PASSCRED: %s", strerror(errno));
+        goto fail;
+    }
+
     ifindex = i;
-    
+
     return fd;
-    
+
 fail:
     if (fd >= 0) {
         close(fd);
         fd = -1;
     }
-    
+
     return -1;
 }
 
@@ -104,16 +108,16 @@ static int process_nlmsg(struct nlmsghdr *n) {
         struct ifinfomsg *ifi;
         ifi = NLMSG_DATA(n);
 
-        if (ifi->ifi_family != AF_UNSPEC || ifi->ifi_index != ifindex)
+        if (ifi->ifi_family != AF_UNSPEC || (int) ifi->ifi_index != ifindex)
             return 0;
-        
+
         if (n->nlmsg_type == RTM_DELLINK) {
             daemon_log(LOG_ERR, "Interface vanished.");
             return -1;
         }
 
         assert(n->nlmsg_type == RTM_NEWLINK);
-        
+
         if ((ifi->ifi_flags & IFF_LOOPBACK) ||
             (ifi->ifi_flags & IFF_NOARP) ||
             ifi->ifi_type != ARPHRD_ETHER) {
@@ -130,10 +134,10 @@ static int process_nlmsg(struct nlmsghdr *n) {
         int l;
         uint32_t address = 0;
         Address *i;
-        
+
         ifa = NLMSG_DATA(n);
 
-        if (ifa->ifa_family != AF_INET || ifa->ifa_index != ifindex)
+        if (ifa->ifa_family != AF_INET || (int) ifa->ifa_index != ifindex)
             return 0;
 
         l = NLMSG_PAYLOAD(n, sizeof(*ifa));
@@ -148,7 +152,7 @@ static int process_nlmsg(struct nlmsghdr *n) {
                     memcpy(&address, RTA_DATA(a), sizeof(uint32_t));
                     break;
             }
-            
+
             a = RTA_NEXT(a, l);
         }
 
@@ -174,20 +178,48 @@ static int process_nlmsg(struct nlmsghdr *n) {
 
 static int process_response(int wait_for_done, unsigned seq) {
     assert(fd >= 0);
-    
+
     do {
         size_t bytes;
         ssize_t r;
-        char replybuf[2048];
+        char replybuf[8*1024];
+        char cred_msg[CMSG_SPACE(sizeof(struct ucred))];
+        struct msghdr msghdr;
+        struct cmsghdr *cmsghdr;
+        struct ucred *ucred;
+        struct iovec iov;
         struct nlmsghdr *p = (struct nlmsghdr *) replybuf;
 
-        if ((r = recv(fd, replybuf, sizeof(replybuf), 0)) < 0) {
-            daemon_log(LOG_ERR, "recv() failed: %s", strerror(errno));
+        memset(&iov, 0, sizeof(iov));
+        iov.iov_base = replybuf;
+ 	iov.iov_len = sizeof(replybuf);
+
+        memset(&msghdr, 0, sizeof(msghdr));
+        msghdr.msg_name = (void*) NULL;
+        msghdr.msg_namelen = 0;
+        msghdr.msg_iov = &iov;
+        msghdr.msg_iovlen = 1;
+        msghdr.msg_control = cred_msg;
+        msghdr.msg_controllen = sizeof(cred_msg);
+ 	msghdr.msg_flags = 0;
+
+        if ((r = recvmsg(fd, &msghdr, 0)) < 0) {
+            daemon_log(LOG_ERR, "recvmsg() failed: %s", strerror(errno));
+            return -1;
+        }
+
+        if (!(cmsghdr = CMSG_FIRSTHDR(&msghdr)) || cmsghdr->cmsg_type != SCM_CREDENTIALS) {
+            daemon_log(LOG_WARNING, "No sender credentials received, ignoring data.");
             return -1;
         }
 
+        ucred = (struct ucred*) CMSG_DATA(cmsghdr);
+
+        if (ucred->uid != 0)
+            return -1;
+
         bytes = (size_t) r;
-        
+
         for (; bytes > 0; p = NLMSG_NEXT(p, bytes)) {
 
             if (!NLMSG_OK(p, bytes) || bytes < sizeof(struct nlmsghdr) || bytes < p->nlmsg_len) {
@@ -224,7 +256,7 @@ int iface_get_initial_state(State *state) {
 
     assert(fd >= 0);
     assert(state);
-    
+
     memset(&req, 0, sizeof(req));
     n = (struct nlmsghdr*) req;
     n->nlmsg_len = NLMSG_LENGTH(sizeof(*ifi));
@@ -244,7 +276,7 @@ int iface_get_initial_state(State *state) {
 
     if (process_response(1, 0) < 0)
         return -1;
-    
+
     n->nlmsg_type = RTM_GETADDR;
     n->nlmsg_len = NLMSG_LENGTH(sizeof(*ifa));
     n->nlmsg_seq = ++seq;
@@ -252,7 +284,7 @@ int iface_get_initial_state(State *state) {
     ifa = NLMSG_DATA(n);
     ifa->ifa_family = AF_INET;
     ifa->ifa_index = ifindex;
-    
+
     if (send(fd, n, n->nlmsg_len, 0) < 0) {
         daemon_log(LOG_ERR, "send(): %s", strerror(errno));
         return -1;
@@ -262,7 +294,7 @@ int iface_get_initial_state(State *state) {
         return -1;
 
     *state = addresses ? STATE_SLEEPING : STATE_START;
-    
+
     return 0;
 }
 
@@ -271,7 +303,7 @@ int iface_process(Event *event) {
     assert(fd >= 0);
 
     b = !!addresses;
-    
+
     if (process_response(0, 0) < 0)
         return -1;
 
@@ -279,13 +311,13 @@ int iface_process(Event *event) {
         *event = EVENT_ROUTABLE_ADDR_UNCONFIGURED;
     else if (!b && addresses)
         *event = EVENT_ROUTABLE_ADDR_CONFIGURED;
-    
+
     return 0;
 }
 
 void iface_done(void) {
     Address *a;
-    
+
     if (fd >= 0) {
         close(fd);
         fd = -1;