Add PROXY command. Not actually an IRC protocol command, it's a HAProxy

trick supported by stunnel to indicate where the connection originally
came from. Looks a little better on public servers.

3 files changed, 94 insertions, 26 deletions

diff --git a/irc.c b/irc.c
index 7f3f66a7..655aa967 100644
--- a/irc.c
+++ b/irc.c
@@ -40,9 +40,6 @@ static char *set_eval_utf8_nicks(set_t *set, char *value);
 irc_t *irc_new(int fd)
 {
 	irc_t *irc;
-	struct sockaddr_storage sock;
-	socklen_t socklen = sizeof(sock);
-	char *host = NULL, *myhost = NULL;
 	irc_user_t *iu;
 	GSList *l;
 	set_t *s;
@@ -64,23 +61,6 @@ irc_t *irc_new(int fd)
 	irc->iconv = (GIConv) - 1;
 	irc->oconv = (GIConv) - 1;
 
-	if (global.conf->hostname) {
-		myhost = g_strdup(global.conf->hostname);
-	} else if (getsockname(irc->fd, (struct sockaddr*) &sock, &socklen) == 0) {
-		myhost = reverse_lookup((struct sockaddr*) &sock, socklen);
-	}
-
-	if (getpeername(irc->fd, (struct sockaddr*) &sock, &socklen) == 0) {
-		host = reverse_lookup((struct sockaddr*) &sock, socklen);
-	}
-
-	if (host == NULL) {
-		host = g_strdup("localhost.localdomain");
-	}
-	if (myhost == NULL) {
-		myhost = g_strdup("localhost.localdomain");
-	}
-
 	if (global.conf->ping_interval > 0 && global.conf->ping_timeout > 0) {
 		irc->ping_source_id = b_timeout_add(global.conf->ping_interval * 1000, irc_userping, irc);
 	}
@@ -127,17 +107,16 @@ irc_t *irc_new(int fd)
 	s = set_add(&b->set, "utf8_nicks", "false", set_eval_utf8_nicks, irc);
 
 	irc->root = iu = irc_user_new(irc, ROOT_NICK);
-	iu->host = g_strdup(myhost);
 	iu->fullname = g_strdup(ROOT_FN);
 	iu->f = &irc_user_root_funcs;
 
 	iu = irc_user_new(irc, NS_NICK);
-	iu->host = g_strdup(myhost);
 	iu->fullname = g_strdup(ROOT_FN);
 	iu->f = &irc_user_root_funcs;
 
 	irc->user = g_new0(irc_user_t, 1);
-	irc->user->host = g_strdup(host);
+	
+	irc_set_hosts(irc, NULL, 0);
 
 	conf_loaddefaults(irc);
 
@@ -153,9 +132,6 @@ irc_t *irc_new(int fd)
 		          "See doc/README for more information.");
 	}
 
-	g_free(myhost);
-	g_free(host);
-
 	/* libpurple doesn't like fork()s after initializing itself, so this
 	   is the right moment to initialize it. */
 #ifdef WITH_PURPLE
@@ -177,6 +153,52 @@ irc_t *irc_new(int fd)
 	return irc;
 }
 
+void irc_set_hosts(irc_t *irc, const struct sockaddr *remote_addr, const socklen_t remote_addrlen)
+{
+	struct sockaddr_storage sock;
+	socklen_t socklen = sizeof(sock);
+	char *host = NULL, *myhost = NULL;
+	struct irc_user *iu;
+
+	if (global.conf->hostname) {
+		myhost = g_strdup(global.conf->hostname);
+	} else if (getsockname(irc->fd, (struct sockaddr*) &sock, &socklen) == 0) {
+		myhost = reverse_lookup((struct sockaddr*) &sock, socklen);
+	}
+
+	if (remote_addrlen > 0) {
+		host = reverse_lookup(remote_addr, remote_addrlen);
+	} else if (getpeername(irc->fd, (struct sockaddr*) &sock, &socklen) == 0) {
+		host = reverse_lookup((struct sockaddr*) &sock, socklen);
+	}
+
+	if (myhost == NULL) {
+		myhost = g_strdup("localhost.localdomain");
+	}
+	if (host == NULL) {
+		host = g_strdup("localhost.localdomain");
+	}
+	
+	if (irc->root->host != irc->root->nick) {
+		g_free(irc->root->host);
+	}
+	irc->root->host = g_strdup(myhost);
+	if ((iu = irc_user_by_name(irc, NS_NICK))) {
+		if (iu->host != iu->nick) {
+			g_free(iu->host);
+		}
+		iu->host = g_strdup(myhost);
+	}
+	
+	if (irc->user->host != irc->user->nick) {
+		g_free(irc->user->host);
+	}
+	irc->user->host = g_strdup(host);
+
+	g_free(myhost);
+	g_free(host);
+}
+
 /* immed=1 makes this function pretty much equal to irc_free(), except that
    this one will "log". In case the connection is already broken and we
    shouldn't try to write to it. */
diff --git a/irc.h b/irc.h
index c56f847f..8a37b0ca 100644
--- a/irc.h
+++ b/irc.h
@@ -26,6 +26,8 @@
 #ifndef _IRC_H
 #define _IRC_H
 
+#include <sys/socket.h>
+
 #define IRC_MAX_LINE 512
 #define IRC_MAX_ARGS 16
 #define IRC_WORD_WRAP 425
@@ -270,6 +272,7 @@ extern GSList *irc_plugins; /* struct irc_plugin */
 extern GSList *irc_connection_list;
 
 irc_t *irc_new(int fd);
+void irc_set_hosts(irc_t *irc, const struct sockaddr *remote_addr, const socklen_t remote_addrlen);
 void irc_abort(irc_t *irc, int immed, char *format, ...) G_GNUC_PRINTF(3, 4);
 void irc_free(irc_t *irc);
 void irc_setpass(irc_t *irc, const char *pass);
diff --git a/irc_commands.c b/irc_commands.c
index dd5bdf38..4a8bae4d 100644
--- a/irc_commands.c
+++ b/irc_commands.c
@@ -58,6 +58,48 @@ static void irc_cmd_pass(irc_t *irc, char **cmd)
 	}
 }
 
+/* http://www.haproxy.org/download/1.8/doc/proxy-protocol.txt
+
+   This isn't actually IRC, it's used by for example stunnel4 to indicate
+   the origin of the secured counterpart of the connection. It'll go wrong
+   with arguments starting with : like for example "::1" but I guess I'm
+   okay with that. */
+static void irc_cmd_proxy(irc_t *irc, char **cmd)
+{
+	struct addrinfo hints, *ai;
+	struct sockaddr_storage sock;
+	socklen_t socklen = sizeof(sock);
+
+	if (getpeername(irc->fd, (struct sockaddr*) &sock, &socklen) != 0) {
+		return;
+	}
+
+	ipv64_normalise_mapped(&sock, &socklen);
+
+	/* Only accept PROXY "command" on localhost sockets. */
+	if (!((sock.ss_family == AF_INET &&
+	       ntohl(((struct sockaddr_in*)&sock)->sin_addr.s_addr) == INADDR_LOOPBACK) ||
+	      (sock.ss_family == AF_INET6 &&
+	       IN6_IS_ADDR_LOOPBACK(&((struct sockaddr_in6*)&sock)->sin6_addr)))) {
+		return;
+	}
+
+	/* And only once. Do this with a pretty dumb regex-match for
+	   now, maybe better to use some sort of flag.. */
+	if (!g_regex_match_simple("^(ip6-)?localhost(.(localdomain.?)?)?$", irc->user->host, 0, 0)) {
+		return;
+	}
+	
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_flags = AI_NUMERICHOST;
+	if (getaddrinfo(cmd[2], NULL, &hints, &ai) != 0) {
+		return;
+	}
+	
+	irc_set_hosts(irc, ai->ai_addr, ai->ai_addrlen);
+	freeaddrinfo(ai);
+}
+
 static gboolean irc_sasl_plain_parse(char *input, char **user, char **pass)
 {
 	int i, part, len;
@@ -807,6 +849,7 @@ static void irc_cmd_rehash(irc_t *irc, char **cmd)
 static const command_t irc_commands[] = {
 	{ "cap",         1, irc_cmd_cap,         0 },
 	{ "pass",        1, irc_cmd_pass,        0 },
+	{ "proxy",       5, irc_cmd_proxy,       IRC_CMD_PRE_LOGIN },
 	{ "user",        4, irc_cmd_user,        IRC_CMD_PRE_LOGIN },
 	{ "nick",        1, irc_cmd_nick,        0 },
 	{ "quit",        0, irc_cmd_quit,        0 },