From: Tom Gundersen <teg@jklm.no>
Date: Sat, 24 May 2014 13:48:47 +0000 (+0200)
Subject: dhcp-network: allow UDP socket to listen on any address
X-Git-Tag: v215~459
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=fef0e0f3b2ad24ed825f04fe1fe60742958f3567;p=elogind.git

dhcp-network: allow UDP socket to listen on any address

For this to work nicely we need to use REUSEADDR so that more than one socket
can be open at the same time. Also, we request the ifindex to be appended
to incoming messages, so we know whence it came.
---

diff --git a/src/libsystemd-network/dhcp-network.c b/src/libsystemd-network/dhcp-network.c
index dd26ef3e0..6fac80e87 100644
--- a/src/libsystemd-network/dhcp-network.c
+++ b/src/libsystemd-network/dhcp-network.c
@@ -68,7 +68,7 @@ int dhcp_network_bind_raw_socket(int index, union sockaddr_union *link,
             .filter = filter
         };
         _cleanup_close_ int s = -1;
-        int r, one = 1;
+        int r, on = 1;
 
         assert(index > 0);
         assert(link);
@@ -77,7 +77,7 @@ int dhcp_network_bind_raw_socket(int index, union sockaddr_union *link,
         if (s < 0)
                 return -errno;
 
-        r = setsockopt (s, SOL_PACKET, PACKET_AUXDATA, &one, sizeof(one));
+        r = setsockopt (s, SOL_PACKET, PACKET_AUXDATA, &on, sizeof(on));
         if (r < 0)
                 return -errno;
 
@@ -117,6 +117,17 @@ int dhcp_network_bind_udp_socket(be32_t address, uint16_t port) {
         r = setsockopt(s, IPPROTO_IP, IP_TOS, &tos, sizeof(tos));
         if (r < 0)
                 return -errno;
+        if (address == INADDR_ANY) {
+                int on = 1;
+
+                r = setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
+                if (r < 0)
+                        return -errno;
+
+                r = setsockopt(s, IPPROTO_IP, IP_PKTINFO, &on, sizeof(on));
+                if (r < 0)
+                        return -errno;
+        }
 
         r = bind(s, &src.sa, sizeof(src.in));
         if (r < 0)