Fill in the source address properly.

git-svn-id: svn+ssh://svn.dolda2000.com/srv/svn/repos/src/icmp-dn@229 959494ce-11ee-0310-bf91-de5d638817bd

diff --git a/icmpdnd.c b/icmpdnd.c
index dd99326..1dfb028 100644 (file)
--- a/icmpdnd.c
+++ b/icmpdnd.c
@@ -132,13 +132,16 @@ void cksum(void *hdr, size_t len)
 int main(int argc, char **argv)
 {
     int i, n, ret;
-    int c, cs, s4, s6, namelen, datalen;
+    int c, cs, s4, s6, datalen;
     int daemonize, ttl;
     unsigned char buf[65536];
     struct sockaddr_storage name;
     struct reqhdr req;
     struct rephdr rep;
     struct iphdr iphdr;
+    struct msghdr mhdr;
+    struct iovec iov;
+    char cmsgbuf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
     size_t hdrlen;
     struct pollfd pfd[2];
     time_t curtime, lasterr;
@@ -168,6 +171,13 @@ int main(int argc, char **argv)
        perror("could not open raw socket");
        exit(1);
     }
+    if(s6 >= 0) {
+       i = 1;
+       if(setsockopt(s6, IPPROTO_IPV6, IPV6_PKTINFO, &i, sizeof(i))) {
+           perror("could not set IPV6_PKTINFO sockopt");
+           exit(1);
+       }
+    }
     
     if(daemonize)
        daemon(0, 0);
@@ -206,9 +216,18 @@ int main(int argc, char **argv)
            if((pfd[i].revents & POLLIN) == 0)
                continue;
            cs = pfd[i].fd;
-           namelen = sizeof(name);
            memset(&name, 0, sizeof(name));
-           ret = recvfrom(cs, buf, sizeof(buf), 0, (struct sockaddr *)&name, &namelen);
+           
+           iov.iov_len = sizeof(buf);
+           iov.iov_base = buf;
+           mhdr.msg_name = &name;
+           mhdr.msg_namelen = sizeof(name);
+           mhdr.msg_iov = &iov;
+           mhdr.msg_iovlen = 1;
+           mhdr.msg_control = cmsgbuf;
+           mhdr.msg_controllen = sizeof(cmsgbuf);
+           
+           ret = recvmsg(cs, &mhdr, 0);
            if(ret < 0) {
                syslog(LOG_WARNING, "error while receiving datagram: %m");
                continue;
@@ -221,11 +240,14 @@ int main(int argc, char **argv)
                memcpy(&iphdr, buf, sizeof(iphdr));
                if(iphdr.protocol != IPPROTO_ICMP)
                    continue;
+               mhdr.msg_control = NULL;
+               mhdr.msg_controllen = 0;
            } else if(cs == s6) {
                if(ret < sizeof(req))
                    continue;
                ((struct sockaddr_in6 *)&name)->sin6_port = 0;
                hdrlen = 0;
+               /* Just keep mhdr.msg_control. */
            } else {
                syslog(LOG_CRIT, "strangeness!");
                abort();
@@ -242,10 +264,12 @@ int main(int argc, char **argv)
            datalen = filldn(buf + sizeof(rep));
        
            cksum(buf, datalen + sizeof(rep));
-       
-           /* XXX: The correct source address needs to be filled in from
-            * the request's destination address. */
-           ret = sendto(cs, buf, datalen + sizeof(rep), 0, (struct sockaddr *)&name, namelen);
+           
+           iov.iov_len = sizeof(rep) + datalen;
+           iov.iov_base = buf;
+           mhdr.msg_iov = &iov;
+           mhdr.msg_iovlen = 1;
+           ret = sendmsg(cs, &mhdr, 0);
            if(ret < 0)
                syslog(LOG_WARNING, "error in sending reply: %m");
        }