send nsctl responses back using the correct source address

Changes

@@ -1,5 +1,6 @@
-* Mon Mar 27 2006 Brendan O'Dea <bod@optus.net> 2.1.17
+* Fri Mar 31 2006 Brendan O'Dea <bod@optus.net> 2.1.17
 - Fix IPCP length test to allow Terminate-Request (4 bytes).
+- Send nsctl responses back using the correct source address (thanks ltd).
 
 * Thu Feb 23 2006 Brendan O'Dea <bod@optus.net> 2.1.16
 - Send configured magic-no in LCP EchoReq when LCP is opened.

THANKS

@@ -25,3 +25,4 @@ Charlie Brady              <charlieb@e-smith.com>
 Jon Morby                  <jon@fido.net>
 Paul Martin                <pm@zetnet.net>
 Jonathan Yarden            <jyarden@bluegrass.net>
+Patrick Cole               <z@amused.net>

l2tpns.c

@@ -4,7 +4,7 @@
 // Copyright (c) 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd) - GPL licenced
 // vim: sw=8 ts=8
 
-char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.156 2006-02-17 13:27:07 bodea Exp $";
+char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.157 2006-04-05 01:45:57 bodea Exp $";
 
 #include <arpa/inet.h>
 #include <assert.h>
@@ -200,7 +200,7 @@ static void initplugins(void);
 static int add_plugin(char *plugin_name);
 static int remove_plugin(char *plugin_name);
 static void plugins_done(void);
-static void processcontrol(uint8_t *buf, int len, struct sockaddr_in *addr, int alen);
+static void processcontrol(uint8_t *buf, int len, struct sockaddr_in *addr, int alen, struct in_addr *local);
 static tunnelidt new_tunnel(void);
 static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vector, size_t vec_len);
 
@@ -3248,6 +3248,7 @@ static void mainloop(void)
 		if (n)
 		{
 			struct sockaddr_in addr;
+			struct in_addr local;
 			socklen_t alen;
 			int c, s;
 			int udp_ready = 0;
@@ -3264,6 +3265,7 @@ static void mainloop(void)
 			for (c = n, i = 0; i < c; i++)
 			{
 				struct event_data *d = events[i].data.ptr;
+
 				switch (d->type)
 				{
 				case FD_TYPE_CLI: // CLI connections
@@ -3290,19 +3292,21 @@ static void mainloop(void)
 
 				case FD_TYPE_CONTROL: // nsctl commands
 					alen = sizeof(addr);
-					processcontrol(buf, recvfrom(controlfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen), &addr, alen);
+					s = recvfromto(controlfd, buf, sizeof(buf), MSG_WAITALL, (struct sockaddr *) &addr, &alen, &local);
+					if (s > 0) processcontrol(buf, s, &addr, alen, &local);
 					n--;
 					break;
 
 				case FD_TYPE_DAE: // DAE requests
 					alen = sizeof(addr);
-					processdae(buf, recvfrom(daefd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen), &addr, alen);
+					s = recvfrom(daefd, buf, sizeof(buf), MSG_WAITALL, (struct sockaddr *) &addr, &alen);
+					if (s > 0) processdae(buf, s, &addr, alen);
 					n--;
 					break;
 
 				case FD_TYPE_RADIUS: // RADIUS response
 					alen = sizeof(addr);
-					s = recvfrom(radfds[d->index], buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen);
+					s = recvfrom(radfds[d->index], buf, sizeof(buf), MSG_WAITALL, (struct sockaddr *) &addr, &alen);
 					if (s >= 0 && config->cluster_iam_master)
 					{
 						if (addr.sin_addr.s_addr == config->radiusserver[0] ||
@@ -4883,7 +4887,7 @@ static void plugins_done()
 		run_plugin_done(p);
 }
 
-static void processcontrol(uint8_t *buf, int len, struct sockaddr_in *addr, int alen)
+static void processcontrol(uint8_t *buf, int len, struct sockaddr_in *addr, int alen, struct in_addr *local)
 {
 	struct nsctl request;
 	struct nsctl response;
@@ -5041,7 +5045,7 @@ static void processcontrol(uint8_t *buf, int len, struct sockaddr_in *addr, int
 	r = pack_control(buf, NSCTL_MAX_PKT_SZ, response.type, response.argc, response.argv);
 	if (r > 0)
 	{
-		sendto(controlfd, buf, r, 0, (const struct sockaddr *) addr, alen);
+		sendtofrom(controlfd, buf, r, 0, (const struct sockaddr *) addr, alen, local);
 		if (log_stream && config->debug >= 4)
 		{
 			LOG(4, 0, 0, "Sent [%s] ", fmtaddr(addr->sin_addr.s_addr, 0));

l2tpns.spec

@@ -43,5 +43,5 @@ rm -rf %{buildroot}
 %attr(644,root,root) /usr/share/man/man[58]/*
 
 %changelog
-* Mon Mar 27 2006 Brendan O'Dea <bod@optus.net> 2.1.17-1
+* Fri Mar 31 2006 Brendan O'Dea <bod@optus.net> 2.1.17-1
 - 2.1.17 release, see /usr/share/doc/l2tpns-2.1.17/Changes

util.c

@@ -1,6 +1,6 @@
 /* Misc util functions */
 
-char const *cvs_id_util = "$Id: util.c,v 1.13 2005-09-19 00:29:12 bodea Exp $";
+char const *cvs_id_util = "$Id: util.c,v 1.14 2006-04-05 01:45:57 bodea Exp $";
 
 #include <unistd.h>
 #include <errno.h>
@@ -20,23 +20,25 @@ char const *cvs_id_util = "$Id: util.c,v 1.13 2005-09-19 00:29:12 bodea Exp $";
 // to use
 char *fmtaddr(in_addr_t addr, int n)
 {
-	static char addrs[4][16];
+    static char addrs[4][16];
-	struct in_addr in;
+    struct in_addr in;
 
-	if (n < 0 || n >= 4) return "";
+    if (n < 0 || n >= 4)
-	in.s_addr = addr;
+	return "";
-	return strcpy(addrs[n], inet_ntoa(in));
+
+    in.s_addr = addr;
+    return strcpy(addrs[n], inet_ntoa(in));
 }
 
 void *shared_malloc(unsigned int size)
 {
-	void * p;
+    void * p;
-	p = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, 0, 0);
+    p = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, 0, 0);
 
-	if (p == MAP_FAILED)
+    if (p == MAP_FAILED)
-		p = NULL;
+	p = NULL;
 
-	return p;
+    return p;
 }
 
 extern int forked;
@@ -45,52 +47,129 @@ extern int *radfds;
 
 pid_t fork_and_close()
 {
-	pid_t pid = fork();
+    pid_t pid = fork();
-	int i;
+    int i;
 
-	if (pid)
+    if (pid)
-		return pid;
+	return pid;
 
-	forked++;
+    forked++;
-	if (config->scheduler_fifo)
+    if (config->scheduler_fifo)
+    {
+	struct sched_param params = {0};
+	params.sched_priority = 0;
+	if (sched_setscheduler(0, SCHED_OTHER, &params))
 	{
-		struct sched_param params = {0};
+	    LOG(0, 0, 0, "Error setting scheduler to OTHER after fork: %s\n", strerror(errno));
-		params.sched_priority = 0;
+	    LOG(0, 0, 0, "This is probably really really bad.\n");
-		if (sched_setscheduler(0, SCHED_OTHER, &params))
-		{
-			LOG(0, 0, 0, "Error setting scheduler to OTHER after fork: %s\n", strerror(errno));
-			LOG(0, 0, 0, "This is probably really really bad.\n");
-		}
 	}
+    }
 
-	signal(SIGPIPE, SIG_DFL);
+    signal(SIGPIPE, SIG_DFL);
-	signal(SIGCHLD, SIG_DFL);
+    signal(SIGCHLD, SIG_DFL);
-	signal(SIGHUP,  SIG_DFL);
+    signal(SIGHUP,  SIG_DFL);
-	signal(SIGUSR1, SIG_DFL);
+    signal(SIGUSR1, SIG_DFL);
-	signal(SIGQUIT, SIG_DFL);
+    signal(SIGQUIT, SIG_DFL);
-	signal(SIGKILL, SIG_DFL);
+    signal(SIGKILL, SIG_DFL);
-	signal(SIGTERM, SIG_DFL);
+    signal(SIGTERM, SIG_DFL);
 
-	// Close sockets
+    // Close sockets
-	if (clifd != -1)          close(clifd);
+    if (clifd != -1)          close(clifd);
-	if (cluster_sockfd != -1) close(cluster_sockfd);
+    if (cluster_sockfd != -1) close(cluster_sockfd);
-	if (tunfd != -1)          close(tunfd);
+    if (tunfd != -1)          close(tunfd);
-	if (udpfd != -1)          close(udpfd);
+    if (udpfd != -1)          close(udpfd);
-	if (controlfd != -1)      close(controlfd);
+    if (controlfd != -1)      close(controlfd);
-	if (daefd != -1)          close(daefd);
+    if (daefd != -1)          close(daefd);
-	if (snoopfd != -1)        close(snoopfd);
+    if (snoopfd != -1)        close(snoopfd);
-	if (ifrfd != -1)          close(ifrfd);
+    if (ifrfd != -1)          close(ifrfd);
-	if (ifr6fd != -1)         close(ifr6fd);
+    if (ifr6fd != -1)         close(ifr6fd);
-	if (rand_fd != -1)        close(rand_fd);
+    if (rand_fd != -1)        close(rand_fd);
-	if (epollfd != -1)        close(epollfd);
+    if (epollfd != -1)        close(epollfd);
+
+    for (i = 0; radfds && i < RADIUS_FDS; i++)
+	close(radfds[i]);
 
-	for (i = 0; radfds && i < RADIUS_FDS; i++)
-		close(radfds[i]);
 #ifdef BGP
-	for (i = 0; i < BGP_NUM_PEERS; i++)
+    for (i = 0; i < BGP_NUM_PEERS; i++)
-		if (bgp_peers[i].sock != -1)
+	if (bgp_peers[i].sock != -1)
-			close(bgp_peers[i].sock);
+	    close(bgp_peers[i].sock);
 #endif /* BGP */
 
-	return pid;
+    return pid;
+}
+
+ssize_t recvfromto(int s, void *buf, size_t len, int flags,
+    struct sockaddr *from, socklen_t *fromlen, struct in_addr *toaddr)
+{
+    ssize_t r;
+    struct msghdr msg;
+    struct cmsghdr *cmsg;
+    struct iovec vec;
+    char cbuf[128];
+
+    memset(&msg, 0, sizeof(msg));
+    msg.msg_name = from;
+    msg.msg_namelen = *fromlen;
+
+    vec.iov_base = buf;
+    vec.iov_len = len;
+    msg.msg_iov = &vec;
+    msg.msg_iovlen = 1;
+    msg.msg_flags = 0;
+
+    msg.msg_control = cbuf;
+    msg.msg_controllen = sizeof(cbuf);
+
+    if ((r = recvmsg(s, &msg, flags)) < 0)
+    	return r;
+
+    if (fromlen)
+	*fromlen = msg.msg_namelen;
+
+    memset(toaddr, 0, sizeof(*toaddr));
+    for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg))
+    {
+	if (cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_PKTINFO)
+	{
+	    struct in_pktinfo *i = (struct in_pktinfo *) CMSG_DATA(cmsg);
+	    memcpy(toaddr, &i->ipi_addr, sizeof(*toaddr));
+	    break;
+	}
+    }
+
+    return r;
+}
+
+ssize_t sendtofrom(int s, void const *buf, size_t len, int flags,
+    struct sockaddr const *to, socklen_t tolen, struct in_addr const *from)
+{
+    struct msghdr msg;
+    struct cmsghdr *cmsg;
+    struct iovec vec;
+    struct in_pktinfo pktinfo;
+    char cbuf[CMSG_SPACE(sizeof(pktinfo))];
+
+    memset(&msg, 0, sizeof(msg));
+    msg.msg_name = (struct sockaddr *) to;
+    msg.msg_namelen = tolen;
+
+    vec.iov_base = (void *) buf;
+    vec.iov_len = len;
+    msg.msg_iov = &vec;
+    msg.msg_iovlen = 1;
+    msg.msg_flags = 0;
+
+    msg.msg_control = cbuf;
+    msg.msg_controllen = sizeof(cbuf);
+
+    cmsg = CMSG_FIRSTHDR(&msg);
+    cmsg->cmsg_level = SOL_IP;
+    cmsg->cmsg_type = IP_PKTINFO;
+    cmsg->cmsg_len = CMSG_LEN(sizeof(pktinfo));
+
+    memset(&pktinfo, 0, sizeof(pktinfo));
+    memcpy(&pktinfo.ipi_spec_dst, from, sizeof(*from));
+    memcpy(CMSG_DATA(cmsg), &pktinfo, sizeof(pktinfo));
+
+    return sendmsg(s, &msg, flags);
 }

util.h

@@ -4,5 +4,10 @@
 char *fmtaddr(in_addr_t addr, int n);
 void *shared_malloc(unsigned int size);
 pid_t fork_and_close(void);
+ssize_t sendtofrom(int s, void const *buf, size_t len, int flags,
+    struct sockaddr const *to, socklen_t tolen, struct in_addr const *from);
+
+ssize_t recvfromto(int s, void *buf, size_t len, int flags,
+    struct sockaddr *from, socklen_t *fromlen, struct in_addr *toaddr);
 
 #endif /* __UTIL_H__ */