X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=secnet.git;a=blobdiff_plain;f=udp.c;h=dde73efb53eb4fe8d0af4555ff30f492bfbab82d;hp=f710250af1a8ed230151bc4db82037d320192610;hb=b3877445fa32f46d70057212cb38347ae1bf4955;hpb=56c8ed69eff8342f692c427ce3d2cab6fd557001

diff --git a/udp.c b/udp.c
index f710250..dde73ef 100644
--- a/udp.c
+++ b/udp.c
@@ -30,6 +30,7 @@ static comm_sendmsg_fn udp_sendmsg;
 struct udp {
     struct udpcommon uc;
     struct udpsocks socks;
+    bool_t addr_configured;
 };
 
 /*
@@ -54,7 +55,7 @@ static const char *udp_addr_to_string(void *commst, const struct comm_addr *ca)
     assert(ix>=0 && ix<socks->n_socks);
     snprintf(sbuf, sizeof(sbuf), "udp:%s%s-%s",
 	     iaddr_to_string(&socks->socks[ix].addr),
-	     ca->ix<0 ? "&" : "",
+	     ca->ix<0 && socks->n_socks>1 ? "&" : "",
 	     iaddr_to_string(&ca->ia));
     return sbuf;
 }
@@ -72,6 +73,37 @@ 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,
+			  const union iaddr *dest, int af,
+			  int r, int errnoval)
+{
+    bool_t success=r>=0;
+    if (us->experienced[!!dest][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%s%s%s",
+	      socks->desc,iaddr_to_string(&us->addr),
+	      success?"success":"trouble",
+	      dest?"transmitting":"receiving",
+	      af?" ":"", af?af_name(af):"",
+	      dest?" (to ":"",
+	      dest?iaddr_to_string(dest):"",
+	      dest?")":"");
+}
+
 static void udp_socks_afterpoll(void *state, struct pollfd *fds, int nfds)
 {
     struct udpsocks *socks=state;
@@ -104,7 +136,7 @@ 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);
@@ -121,7 +153,10 @@ 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))
@@ -136,6 +171,8 @@ static void udp_socks_afterpoll(void *state, struct pollfd *fds, int nfds)
 		}
 		BUF_ASSERT_FREE(cc->rbuf);
 	    } 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);
@@ -162,8 +199,9 @@ 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(us->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, &dest->ia,0, r,errno);
 	buf_unprepend(buf,8);
     } else {
 	int i,r;
@@ -176,6 +214,7 @@ static bool_t udp_sendmsg(void *commst, struct buffer_if *buf,
 		continue;
 	    r=sendto(us->fd, buf->start, buf->size, 0,
 		     &dest->ia.sa, iaddr_socklen(&dest->ia));
+	    udp_sock_experienced(0,uc,socks,us, &dest->ia,af, r,errno);
 	    if (r>=0) return True;
 	    if (!(errno==EAFNOSUPPORT || errno==ENETUNREACH))
 		/* who knows what that error means? */
@@ -195,6 +234,34 @@ void udp_destroy_socket(struct udpcommon *uc, struct udpsock *us)
     }
 }
 
+#define FAIL_LG 0, cc->cl.description, &cc->loc, failmsgclass
+#define FAIL(...) do{						\
+        lg_perror(FAIL_LG,errno,__VA_ARGS__);	\
+	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)
 {
@@ -202,12 +269,7 @@ bool_t udp_make_socket(struct udpcommon *uc, struct udpsock *us,
     struct commcommon *cc=&uc->cc;
     us->fd=-1;
 
-#define FAIL_LG 0, cc->cl.description, &cc->loc, failmsgclass
-#define FAIL(...) do{						\
-        lg_perror(FAIL_LG,errno,__VA_ARGS__);	\
-	goto failed;						\
-    }while(0)
-
+    FILLZERO(us->experienced);
     us->fd=socket(addr->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
     if (us->fd<0) FAIL("socket");
     setnonblock(us->fd);
@@ -225,6 +287,9 @@ bool_t udp_make_socket(struct udpcommon *uc, struct udpsock *us,
     if (uc->authbind) {
 	pid_t c;
 	int status;
+	char desc[200];
+	snprintf(desc,sizeof(desc),"authbind for %s: %s",
+		 iaddr_to_string(addr), uc->authbind);
 
 	/* XXX this fork() and waitpid() business needs to be hidden
 	   in some system-specific library functions. */
@@ -274,10 +339,10 @@ bool_t udp_make_socket(struct udpcommon *uc, struct udpsock *us,
 	    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);
+			  "%s exited with error exit status %d;"
+			  " indicates error",desc,es);
 	    } else {
-		lg_exitstatus(FAIL_LG,status,"authbind");
+		lg_exitstatus(FAIL_LG,status,desc);
 	    }
 	    goto failed;
 	}
@@ -285,18 +350,24 @@ bool_t udp_make_socket(struct udpcommon *uc, struct udpsock *us,
 	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:
     udp_destroy_socket(uc,us);
     return False;
+}
 
 #undef FAIL
-}
 
-void udp_socks_register(struct udpcommon *uc, struct udpsocks *socks)
+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");
 }
@@ -307,16 +378,37 @@ void udp_socks_deregister(struct udpcommon *uc, struct udpsocks *socks)
     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)
 {
     struct udp *st=sst;
     struct udpsocks *socks=&st->socks;
     struct udpcommon *uc=&st->uc;
     int i;
-    for (i=0; i<socks->n_socks; i++)
-	udp_make_socket(uc,&socks->socks[i],M_FATAL);
+    bool_t anydone=0;
+
+    for (i=0; i<socks->n_socks; i++) {
+	bool_t required=st->addr_configured
+	    || (!anydone && i==socks->n_socks-1);
+	anydone += udp_make_socket(uc,&socks->socks[i],
+				   required ? M_FATAL : M_WARNING);
+    }
+
+    udp_socks_register(uc,socks, uc->use_proxy ? "proxy" : "socket");
 
-    udp_socks_register(uc,socks);
+    add_hook(PHASE_CHILDPERSIST,udp_childpersist_hook,st);
 }
 
 static list_t *udp_apply(closure_t *self, struct cloc loc, dict_t *context,
@@ -348,14 +440,16 @@ static list_t *udp_apply(closure_t *self, struct cloc loc, dict_t *context,
     };
 
     caddrl=dict_lookup(d,"address");
-    socks->n_socks=caddrl ? list_length(caddrl) : (int)ARRAY_SIZE(defaultaddrs);
+    st->addr_configured=!!caddrl;
+    socks->n_socks=st->addr_configured ? list_length(caddrl)
+	: (int)ARRAY_SIZE(defaultaddrs);
     if (socks->n_socks<=0 || socks->n_socks>UDP_MAX_SOCKETS)
 	cfgfatal(cc->loc,"udp","`address' must be 1..%d addresses",
 		 UDP_MAX_SOCKETS);
 
     for (i=0; i<socks->n_socks; i++) {
 	struct udpsock *us=&socks->socks[i];
-	if (!list_length(caddrl)) {
+	if (!st->addr_configured) {
 	    us->addr=defaultaddrs[i];
 	} else {
 	    string_item_to_iaddr(list_elem(caddrl,i),uc->port,&us->addr,"udp");