proxy-protocol: accept cross-family proxying

Due to a strict interpretation of the spec if "TCP4" is used we
expect two ipv4 addresses (and similar for "TCP6" and ipv6 addresses).
However, the family specified in the proxy header matters only for
the first address (the source), not the destination!  After all,
it's not strange to proxy from/to ipv4 and ipv6.

Use getaddrinfo(NI_NUMERICHOST) to parse the IP addresses since
inet_pton() is too strict.

1 files changed, 16 insertions, 17 deletions

diff --git a/server.c b/server.c
index aed958d..296fb12 100644
--- a/server.c
+++ b/server.c
@@ -604,7 +604,8 @@ proxy_socket(struct client *c, struct proxy *p)
 		    to, sizeof(to), to_port, sizeof(to_port),
 		    NI_NUMERICHOST|NI_NUMERICSERV);
 		if (err != 0) {
-			log_warnx("getnameinfo failed: %s", gai_strerror(err));
+			log_warnx("%s: getnameinfo failed: %s", __func__,
+			    gai_strerror(err));
 			strlcpy(to, c->rhost, sizeof(to));
 			strlcpy(to_port, c->rserv, sizeof(to_port));
 		}
@@ -1324,7 +1325,7 @@ read_cb(struct tls *ctx, void *buf, size_t buflen, void *cb_arg)
 	char			 protostr[1024];
 	ssize_t			 ret;
 	size_t			 left, avail, copy, consumed;
-	int			 status;
+	int			 err, status;
 
 	if (!c->proxy_proto) {
 		/* no buffer to cache into, read into libtls buffer */
@@ -1370,22 +1371,19 @@ read_cb(struct tls *ctx, void *buf, size_t buflen, void *cb_arg)
 		return -1;
 	}
 
-	switch (pp1.proto) {
-	case PROTO_V4:
-		inet_ntop(AF_INET, &pp1.srcaddr.v4, c->rhost,
-		    sizeof(c->rhost));
-		break;
-	case PROTO_V6:
-		inet_ntop(AF_INET6, &pp1.srcaddr.v6, c->rhost,
-		    sizeof(c->rhost));
-		break;
-	case PROTO_UNKNOWN:
+	if (pp1.proto == PROTO_UNKNOWN)
 		strlcpy(c->rhost, "UNKNOWN", sizeof(c->rhost));
-		break;
-	}
-
-	if (pp1.proto != PROTO_UNKNOWN)
+	else {
+		err = getnameinfo((struct sockaddr *)&pp1.srcaddr, pp1.srclen,
+		    c->rhost, sizeof(c->rhost), NULL, 0,
+		    NI_NUMERICHOST);
+		if (err) {
+			log_warn("%s: getnameinfo failed: %s", __func__,
+			    gai_strerror(err));
+			return -1;
+		}
 		snprintf(c->rserv, sizeof(c->rserv), "%u", pp1.srcport);
+	}
 
 	proxy_proto_v1_string(&pp1, protostr, sizeof(protostr));
 	log_debug("proxy-protocol v1: %s", protostr);
@@ -1450,7 +1448,8 @@ server_accept(int sock, short et, void *d)
 	e = getnameinfo(sraddr, len, c->rhost, sizeof(c->rhost),
 	    c->rserv, sizeof(c->rserv), NI_NUMERICHOST | NI_NUMERICSERV);
 	if (e != 0) {
-		log_warnx("getnameinfo failed: %s", gai_strerror(e));
+		log_warnx("%s: getnameinfo failed: %s", __func__,
+		    gai_strerror(e));
 		close(c->fd);
 		free(c);
 		return;