X-Git-Url: https://git.distorted.org.uk/~mdw/secnet/blobdiff_plain/53f4e66603bcc2d21c70ad7a69db5fda6da5d645..b4ececfc649ba051ccffe1029637f7262a59d8a0:/udp.c

diff --git a/udp.c b/udp.c
index 8f0bb8b..06acf33 100644
--- a/udp.c
+++ b/udp.c
@@ -72,6 +72,34 @@ static int udp_socks_beforepoll(void *state, struct pollfd *fds, int *nfds_io,
     return 0;
 }
 
+const char *af_name(int af)
+{
+    switch (af) {
+    case AF_INET6: return "IPv6";
+    case AF_INET:  return "IPv4";
+    case 0:        return "(any)";
+    default: abort();
+    }
+}
+
+void udp_sock_experienced(struct log_if *lg, struct udpcommon *uc,
+			  struct udpsocks *socks, struct udpsock *us,
+			  bool_t recvsend, int af,
+			  int r, int errnoval)
+{
+    bool_t success=r>=0;
+    if (us->experienced[recvsend][af][success]++)
+	return;
+    lg_perror(lg, uc->cc.cl.description, &uc->cc.loc,
+	      success ? M_INFO : M_WARNING,
+	      success ? 0 : errnoval,
+	      "%s %s experiencing some %s %s%s%s",
+	      socks->desc,iaddr_to_string(&us->addr),
+	      success?"success":"trouble",
+	      recvsend?"transmitting":"receiving",
+	      af?" ":"", af?af_name(af):"");
+}
+
 static void udp_socks_afterpoll(void *state, struct pollfd *fds, int nfds)
 {
     struct udpsocks *socks=state;
@@ -85,10 +113,11 @@ static void udp_socks_afterpoll(void *state, struct pollfd *fds, int nfds)
     struct commcommon *cc=&uc->cc;
 
     for (i=0; i<socks->n_socks; i++) {
+	struct udpsock *us=&socks->socks[i];
 	if (i>=nfds) continue;
 	if (!(fds[i].revents & POLLIN)) continue;
-	assert(fds[i].fd == socks->socks[i].fd);
-	int fd=socks->socks[i].fd;
+	assert(fds[i].fd == us->fd);
+	int fd=us->fd;
 	do {
 	    fromlen=sizeof(from);
 	    BUF_ASSERT_FREE(cc->rbuf);
@@ -103,7 +132,7 @@ static void udp_socks_afterpoll(void *state, struct pollfd *fds, int nfds)
 		    /* Check that the packet came from our poxy server;
 		       we shouldn't be contacted directly by anybody else
 		       (since they can trivially forge source addresses) */
-		    if (!iaddr_equal(&from,&uc->proxy)) {
+		    if (!iaddr_equal(&from,&uc->proxy,False)) {
 			Message(M_INFO,"udp: received packet that's not "
 				"from the proxy\n");
 			BUF_FREE(cc->rbuf);
@@ -120,7 +149,10 @@ static void udp_socks_afterpoll(void *state, struct pollfd *fds, int nfds)
 		ca.ia=from;
 		ca.ix=i;
 		done=comm_notify(&cc->notify, cc->rbuf, &ca);
-		if (!done) {
+		if (done) {
+		    udp_sock_experienced(0,uc,socks,us,0,
+					 from.sa.sa_family,0,0);
+		} else {
 		    uint32_t msgtype;
 		    if (cc->rbuf->size>12 /* prevents traffic amplification */
 			&& ((msgtype=get_uint32(cc->rbuf->start+8))
@@ -134,7 +166,9 @@ static void udp_socks_afterpoll(void *state, struct pollfd *fds, int nfds)
 		    BUF_FREE(cc->rbuf);
 		}
 		BUF_ASSERT_FREE(cc->rbuf);
-	    } else {
+	    } else { /* rv<=0 */
+		if (errno!=EINTR && !iswouldblock(errno))
+		    udp_sock_experienced(0,uc,socks,us, 0,0, rv,errno);
 		BUF_FREE(cc->rbuf);
 	    }
 	} while (rv>=0);
@@ -150,6 +184,7 @@ static bool_t udp_sendmsg(void *commst, struct buffer_if *buf,
     uint8_t *sa;
 
     if (uc->use_proxy) {
+	struct udpsock *us=&socks->socks[0];
 	sa=buf_prepend(buf,8);
 	if (dest->ia.sa.sa_family != AF_INET) {
 	    Message(M_INFO,
@@ -160,18 +195,22 @@ static bool_t udp_sendmsg(void *commst, struct buffer_if *buf,
 	memcpy(sa,&dest->ia.sin.sin_addr,4);
 	memset(sa+4,0,4);
 	memcpy(sa+6,&dest->ia.sin.sin_port,2);
-	sendto(socks->socks[0].fd,sa,buf->size+8,0,&uc->proxy.sa,
+	int r=sendto(us->fd,sa,buf->size+8,0,&uc->proxy.sa,
 	       iaddr_socklen(&uc->proxy));
+	udp_sock_experienced(0,uc,socks,us, 1,0, r,errno);
 	buf_unprepend(buf,8);
     } else {
 	int i,r;
 	bool_t allunsupported=True;
+	int af=dest->ia.sa.sa_family;
 	for (i=0; i<socks->n_socks; i++) {
-	    if (dest->ia.sa.sa_family != socks->socks[i].addr.sa.sa_family)
+	    struct udpsock *us=&socks->socks[i];
+	    if (us->addr.sa.sa_family != af)
 		/* no point even trying */
 		continue;
-	    r=sendto(socks->socks[i].fd, buf->start, buf->size, 0,
+	    r=sendto(us->fd, buf->start, buf->size, 0,
 		     &dest->ia.sa, iaddr_socklen(&dest->ia));
+	    udp_sock_experienced(0,uc,socks,us, 1,af, r,errno);
 	    if (r>=0) return True;
 	    if (!(errno==EAFNOSUPPORT || errno==ENETUNREACH))
 		/* who knows what that error means? */
@@ -183,12 +222,13 @@ static bool_t udp_sendmsg(void *commst, struct buffer_if *buf,
     return True;
 }
 
-bool_t udp_make_socket(struct udpcommon *uc, struct udpsock *us,
-		       int failmsgclass)
+void udp_destroy_socket(struct udpcommon *uc, struct udpsock *us)
 {
-    const union iaddr *addr=&us->addr;
-    struct commcommon *cc=&uc->cc;
-    us->fd=-1;
+    if (us->fd>=0) {
+	close(us->fd);
+	us->fd=-1;
+    }
+}
 
 #define FAIL_LG 0, cc->cl.description, &cc->loc, failmsgclass
 #define FAIL(...) do{						\
@@ -196,10 +236,39 @@ bool_t udp_make_socket(struct udpcommon *uc, struct udpsock *us,
 	goto failed;						\
     }while(0)
 
+static bool_t record_socket_gotaddr(struct udpcommon *uc, struct udpsock *us,
+				    int failmsgclass)
+{
+    struct commcommon *cc=&uc->cc;
+    socklen_t salen=sizeof(us->addr);
+    int r=getsockname(us->fd,&us->addr.sa,&salen);
+    if (r) FAIL("getsockname()");
+    if (salen>sizeof(us->addr)) { errno=0; FAIL("getsockname() length"); }
+    return True;
+
+ failed:
+    return False;
+}
+
+bool_t udp_import_socket(struct udpcommon *uc, struct udpsock *us,
+			 int failmsgclass, int fd)
+{
+    FILLZERO(us->experienced);
+    us->fd=fd;
+    return record_socket_gotaddr(uc,us,failmsgclass);
+}
+
+bool_t udp_make_socket(struct udpcommon *uc, struct udpsock *us,
+		       int failmsgclass)
+{
+    const union iaddr *addr=&us->addr;
+    struct commcommon *cc=&uc->cc;
+    us->fd=-1;
+
+    FILLZERO(us->experienced);
     us->fd=socket(addr->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
     if (us->fd<0) FAIL("socket");
-    if (fcntl(us->fd, F_SETFL, fcntl(us->fd, F_GETFL)|O_NONBLOCK)==-1)
-	FAIL("fcntl(set O_NONBLOCK)");
+    setnonblock(us->fd);
     setcloexec(us->fd);
 #ifdef CONFIG_IPV6
     if (addr->sa.sa_family==AF_INET6) {
@@ -224,6 +293,7 @@ bool_t udp_make_socket(struct udpcommon *uc, struct udpsock *us,
 	    char *argv[5], addrstr[33], portstr[5];
 	    const char *addrfam;
 	    int port;
+	    afterfork();
 	    switch (addr->sa.sa_family) {
 	    case AF_INET:
 		sprintf(addrstr,"%08lX",(long)addr->sin.sin_addr.s_addr);
@@ -258,37 +328,60 @@ bool_t udp_make_socket(struct udpcommon *uc, struct udpsock *us,
 	    if (errno==EINTR) continue;
 	    FAIL("waitpid for authbind");
 	}
-	if (WIFSIGNALED(status)) {
-	    lg_perror(FAIL_LG,0,"authbind died on signal %s (%d)",
-			strsignal(WTERMSIG(status)),WTERMSIG(status));
-	    goto failed;
-	}
-	if (WIFEXITED(status) && WEXITSTATUS(status)!=0) {
-	    lg_perror(FAIL_LG,0,
-		      "authbind died with error exit status %d",
-		      WEXITSTATUS(status));
+	if (status) {
+	    if (WIFEXITED(status) && WEXITSTATUS(status)<127) {
+		int es=WEXITSTATUS(status);
+		lg_perror(FAIL_LG,es,
+			  "authbind exited with error exit status %d;"
+			  " indicates error",es);
+	    } else {
+		lg_exitstatus(FAIL_LG,status,"authbind");
+	    }
 	    goto failed;
 	}
     } else {
 	if (bind(us->fd, &addr->sa, iaddr_socklen(addr))!=0)
 	    FAIL("bind (%s)",iaddr_to_string(addr));
     }
+
+    bool_t ok=record_socket_gotaddr(uc,us,failmsgclass);
+    if (!ok) goto failed;
+
     return True;
 
 failed:
-    if (us->fd>=0) {
-	close(us->fd);
-	us->fd=-1;
-    }
+    udp_destroy_socket(uc,us);
     return False;
+}
 
 #undef FAIL
+
+void udp_socks_register(struct udpcommon *uc, struct udpsocks *socks,
+			const char *desc)
+{
+    socks->uc=uc;
+    socks->desc=desc;
+    socks->interest=
+	register_for_poll(socks,udp_socks_beforepoll,udp_socks_afterpoll,"udp");
 }
 
-void udp_socks_register(struct udpcommon *uc, struct udpsocks *socks)
+void udp_socks_deregister(struct udpcommon *uc, struct udpsocks *socks)
 {
     socks->uc=uc;
-    register_for_poll(socks,udp_socks_beforepoll,udp_socks_afterpoll,"udp");
+    deregister_for_poll(socks->interest);
+}
+
+void udp_socks_childpersist(struct udpcommon *uc, struct udpsocks *socks)
+{
+    int i;
+    for (i=0; i<socks->n_socks; i++)
+	udp_destroy_socket(uc,&socks->socks[i]);
+}
+
+static void udp_childpersist_hook(void *sst, uint32_t new_phase)
+{
+    struct udp *st=sst;
+    udp_socks_childpersist(&st->uc,&st->socks);
 }
 
 static void udp_phase_hook(void *sst, uint32_t new_phase)
@@ -300,7 +393,9 @@ static void udp_phase_hook(void *sst, uint32_t new_phase)
     for (i=0; i<socks->n_socks; i++)
 	udp_make_socket(uc,&socks->socks[i],M_FATAL);
 
-    udp_socks_register(uc,socks);
+    udp_socks_register(uc,socks, uc->use_proxy ? "proxy" : "socket");
+
+    add_hook(PHASE_CHILDPERSIST,udp_childpersist_hook,st);
 }
 
 static list_t *udp_apply(closure_t *self, struct cloc loc, dict_t *context,