Handle CAP requests from clients, reply with no capabilities

Some clients require the server to handle CAP requests (IRCv3).
This adds basic support for CAP requests during the authentication
phase, sending no capabilities on CAP LS or CAP LIST, and CAP NAK
with all requested capabilities listed on CAP REQ.

This will be a base for adding capabilities later.

Signed-off-by: Loïc Gomez <bip@animanova.fr>

Makefile.am

@@ -3,7 +3,7 @@ if COND_WANT_TESTS
 endif
 SUBDIRS = src . $(MAYBE_TESTS)
 
-dist_man_MANS = bip.1 bip.conf.5 bipmkpw.1
+dist_man_MANS = bip.1 bip.conf.5 bipmkpw.1 bipgenconfig.1
 
 examplesdir = $(prefix)/share/doc/bip/examples/
 dist_examples_DATA = samples/bip.conf samples/bip.vim

bip.conf.5

@@ -146,7 +146,7 @@ Defines the delay between each logfiles sync to the disk. Must be a non null
 positive integer.
 
 .TP
-\fBreconn_timer\fP (default: \fB120\fP)
+\fBreconn_timer\fP (default: \fB30\fP)
 Defines the initial delay (in seconds) before a reconnection attempt.
 The delay increases with the number of attempts:
 delay = reconn_timer * number of attempts
@@ -227,7 +227,7 @@ This option should of course not be enabled if \fBbacklog_lines\fP is 0 !
 If you still want to do so, don't forget to \fB/BIP BLRESET\fP sometimes.
 
 .TP
-\fBbacklog_lines\fP (default: \fB10\fP)
+\fBbacklog_lines\fP (default: \fB0\fP)
 If set to 0, BIP will replay all the logs since last client disconnect. Else,
 it'll replay exactly \fBbacklog_lines\fP lines on each channel and privates.
 Be aware that BIP will replay \fBbacklog_lines\fP lines of all privates, even

samples/bip.conf

@@ -86,7 +86,7 @@
 # Sets the initial delay (in seconds) before a reconnection attempt.
 # The delay increases with the number of attempts:
 # delay = reconn_timer * number of attempts
-#reconn_timer = 120;
+#reconn_timer = 30;
 
 # Network definition, a name and server info
 #network {

scripts/bipgenconfig

@@ -119,7 +119,7 @@ my %optdesc = (
 			'optional' => 1,
 			'depends' => 'log', 'depval' => 'true',
 			'desc' => 'Do you want to activate backlog {play back logs} system ?' },
-		'backlog_lines' => { 'type' => 'i', 'adv' => 0, 'default' => '10',
+		'backlog_lines' => { 'type' => 'i', 'adv' => 0, 'default' => '0',
 			'optional' => 1,
 			'depends' => 'backlog', 'depval' => 'true',
 			'desc' => 'How much line do you want bip to play back upon client connect' .

src/bip.c

@@ -67,6 +67,7 @@ void conf_die(bip_t *bip, char *fmt, ...);
 static char *get_tuple_pvalue(list_t *tuple_l, int lex);
 void bip_notify(struct link_client *ic, char *fmt, ...);
 void adm_list_connections(struct link_client *ic, struct bipuser *bu);
+struct link *find_link(const char *link_name, struct bipuser *bu);
 void free_conf(list_t *l);
 
 
@@ -373,6 +374,45 @@ static int add_network(bip_t *bip, list_t *data)
 	return 1;
 }
 
+void adm_bip_jump(struct link_client *ic, const char *conn_name,
+		  int reset_timer)
+{
+	struct link *lnk;
+	if (conn_name) {
+		lnk = find_link(conn_name, LINK(ic)->user);
+		if (!lnk) {
+			bip_notify(ic, "-- Cannot find connection named %s",
+				   conn_name);
+			return;
+		}
+		goto do_the_jump;
+	} else {
+		lnk = LINK(ic);
+	}
+
+do_the_jump:
+	if (!lnk->l_server) {
+		if (reset_timer) {
+			lnk->recon_timer = 0;
+			bip_notify(ic,
+				   "-- %s is not connected, "
+				   "timer has been reset, please wait",
+				   conn_name);
+			return;
+		}
+		int timer = (lnk->recon_timer ? lnk->recon_timer : 0);
+		bip_notify(ic,
+			   "-- %s is not connected, "
+			   "please wait for reconnect (%ds)",
+			   conn_name, timer);
+		return;
+	}
+
+	WRITE_LINE1(CONN(lnk->l_server), NULL, "QUIT", "jumpin' jumpin'");
+	connection_close(CONN(lnk->l_server));
+	bip_notify(ic, "-- Jumping to next server on %s", conn_name);
+}
+
 void adm_bip_delconn(bip_t *bip, struct link_client *ic, const char *conn_name)
 {
 	struct bipuser *user = LINK(ic)->user;
@@ -664,6 +704,31 @@ static int add_connection(bip_t *bip, struct bipuser *user, list_t *data)
 	return 1;
 }
 
+struct link *find_link(const char *link_name, struct bipuser *bu)
+{
+	list_iterator_t it;
+
+	// Immediately return NULL when bip user (bu) is NULL
+	if (!bu) {
+		return NULL;
+	}
+
+	for (list_it_init(&_bip->link_list, &it); list_it_item(&it);
+	     list_it_next(&it)) {
+		struct link *lnk = list_it_item(&it);
+		if (!lnk)
+			continue;
+		// Only lookup in optionally specified user links
+		if (bu != lnk->user)
+			continue;
+
+		if (strcmp(link_name, lnk->name) == 0)
+			return lnk;
+	}
+
+	return NULL;
+}
+
 static char *get_tuple_pvalue(list_t *tuple_l, int lex)
 {
 	struct tuple *t;
@@ -1992,8 +2057,8 @@ void adm_bip_help(struct link_client *ic, int admin, const char *subhelp)
 			bip_notify(ic, "/BIP LIST networks|connections");
 		}
 		bip_notify(ic,
-			   "/BIP JUMP # jump to next server (in same "
+			   "/BIP JUMP [-f] [conn_name] # jump to next "
-			   "network)");
+			   "server (defaults to current network)");
 		bip_notify(ic,
 			   "/BIP BLRESET [channel|query]# reset backlog "
 			   "(this connection only). Add -q flag and the "
@@ -2046,8 +2111,14 @@ void adm_bip_help(struct link_client *ic, int admin, const char *subhelp)
 			   "  Removing a connection will cause "
 			   "its disconnection.");
 	} else if (strcasecmp(subhelp, "JUMP") == 0) {
-		bip_notify(ic, "/BIP JUMP :");
+		bip_notify(ic, "/BIP JUMP [-f] [conn_name]:");
 		bip_notify(ic, "  Jump to next server in current network.");
+		bip_notify(ic,
+			   "  If [conn_name] is set, jump to next server in "
+			   "[conn_name] network instead.");
+		bip_notify(ic,
+			   "  If [-f] flag is used, also resets reconnect "
+			   "timer.");
 	} else if (strcasecmp(subhelp, "BLRESET") == 0) {
 		bip_notify(ic, "/BIP BLRESET :");
 		bip_notify(ic, "  Reset backlog on this network.");
@@ -2227,12 +2298,16 @@ int adm_bip(bip_t *bip, struct link_client *ic, struct line *line, int privmsg)
 			bip_notify(ic, "-- Invalid INFO request");
 		}
 	} else if (irc_line_elem_case_equals(line, privmsg + 1, "JUMP")) {
-		if (LINK(ic)->l_server) {
+		if (irc_line_count(line) == privmsg + 2) {
-			WRITE_LINE1(CONN(LINK(ic)->l_server), NULL, "QUIT",
+			adm_bip_jump(ic, NULL, 0);
-				    "jumpin' jumpin'");
+		} else if (irc_line_count(line) == privmsg + 3) {
-			connection_close(CONN(LINK(ic)->l_server));
+			adm_bip_jump(ic, irc_line_elem(line, privmsg + 2), 0);
+		} else if (irc_line_count(line) == privmsg + 4
+			   && irc_line_elem_equals(line, privmsg + 2, "-f")) {
+			adm_bip_jump(ic, irc_line_elem(line, privmsg + 3), 1);
+		} else {
+			bip_notify(ic, "-- Invalid usage (/BIP HELP JUMP)");
 		}
-		bip_notify(ic, "-- Jumping to next server");
 	} else if (irc_line_elem_case_equals(line, privmsg + 1, "BLRESET")) {
 		if (irc_line_includes(line, privmsg + 2)) {
 			if (irc_line_elem_equals(line, privmsg + 2, "-q")) {

src/defaults.h

@@ -19,7 +19,7 @@
 #define DEFAULT_BACKLOG 1
 #define DEFAULT_ALWAYS_BACKLOG 0
 #define DEFAULT_BL_MSG_ONLY 0
-#define DEFAULT_BACKLOG_LINES 10
+#define DEFAULT_BACKLOG_LINES 0
 #define DEFAULT_BACKLOG_TIMESTAMP BLTSTime
 #define DEFAULT_BLRESET_ON_TALK 0
 #define DEFAULT_BLRESET_CONNECTION 0
@@ -29,6 +29,6 @@
 #define DEFAULT_LOG_LEVEL LOG_INFO
 #define DEFAULT_LOG_FORMAT "%u/%n/%Y-%m/%c.%d.log"
 #define DEFAULT_BIP_USE_NOTICE 0
-#define DEFAULT_RECONN_TIMER 120
+#define DEFAULT_RECONN_TIMER 30
 
 #endif /* DEFAULTS_H */

src/irc.c

@@ -33,6 +33,7 @@
 extern int sighup;
 extern bip_t *_bip;
 
+static int irc_generic_error(struct link_server *server, struct line *line);
 static int irc_join(struct link_server *server, struct line *line);
 static int irc_part(struct link_server *server, struct line *line);
 static int irc_mode(struct link_server *server, struct line *line);
@@ -625,6 +626,10 @@ int irc_dispatch_server(bip_t *bip, struct link_server *server,
 		ret = irc_quit(server, line);
 	} else if (irc_line_elem_equals(line, 0, "NICK")) {
 		ret = irc_nick(server, line);
+	} else if (irc_line_is_error(line)) {
+		// IRC errors catchall (for unhandled ones)
+		// logs error to bip.log
+		ret = irc_generic_error(server, line);
 	}
 
 	if (ret == OK_COPY) {
@@ -1025,6 +1030,31 @@ static int irc_cli_pass(bip_t *bip, struct link_client *ic, struct line *line)
 	return OK_FORGET;
 }
 
+static int irc_cli_cap(bip_t *bip, struct link_client *ic, struct line *line)
+{
+	if (irc_line_count(line) < 2)
+		return ERR_PROTOCOL;
+
+	/* When we decide to enable actual capabilities, we'll have to handle CAP
+	 * version, add a flag cap_started or similar, and handle CAP END.
+	 */
+	if (irc_line_elem_equals(line, 1, "LS")) {
+		WRITE_LINE2(CONN(ic), NULL, "CAP", "*", "LS");
+	} else if (irc_line_elem_equals(line, 1, "LIST")) {
+		WRITE_LINE3(CONN(ic), NULL, "CAP", "*", "LIST", "");
+	} else if (irc_line_elem_equals(line, 1, "REQ")) {
+		char *caps = irc_line_to_string_skip(line, 2);
+		if (caps) {
+			caps++;
+			WRITE_LINE3(CONN(ic), NULL, "CAP", "*", "NAK", caps);
+		}
+	}
+
+	if ((ic->state & IRCC_READY) == IRCC_READY)
+		return irc_cli_startup(bip, ic, line);
+	return OK_FORGET;
+}
+
 static int irc_cli_quit(struct link_client *ic, struct line *line)
 {
 	(void)ic;
@@ -1403,6 +1433,8 @@ static int irc_dispatch_logging_client(bip_t *bip, struct link_client *ic,
 		return irc_cli_user(bip, ic, line);
 	} else if (irc_line_elem_equals(line, 0, "PASS")) {
 		return irc_cli_pass(bip, ic, line);
+	} else if (irc_line_elem_equals(line, 0, "CAP")) {
+		return irc_cli_cap(bip, ic, line);
 	}
 	return OK_FORGET;
 }
@@ -1448,6 +1480,17 @@ static int origin_is_me(struct line *l, struct link_server *server)
 	return 0;
 }
 
+static int irc_generic_error(struct link_server *server, struct line *line)
+{
+	if (irc_line_count(line) == 4)
+		mylog(LOG_INFO, "[%s] IRC error: %s", LINK(server)->name,
+			irc_line_elem(line, 3));
+	else
+		mylog(LOG_INFO, "[%s] IRC error: %s", LINK(server)->name,
+			irc_line_to_string(line));
+	return OK_COPY;
+}
+
 static int irc_join(struct link_server *server, struct line *line)
 {
 	char *s_nick;

src/line.c

@@ -16,6 +16,8 @@
 #include "line.h"
 #include "util.h"
 
+char *_irc_line_to_string(struct line *l, int skip_first);
+
 // TODO resolve assuming signed overflow does not occur when changing X +- C1
 // cmp C2 to X cmp C2 -+ C1
 #pragma GCC diagnostic ignored "-Wstrict-overflow"
@@ -76,6 +78,19 @@ void irc_line_append(struct line *l, const char *s)
 }
 
 char *irc_line_to_string(struct line *l)
+{
+    return _irc_line_to_string(l, 0);
+}
+
+char *irc_line_to_string_skip(struct line *l, int skip_first)
+{
+    if (skip_first >= irc_line_count(l)) {
+        return NULL;
+    }
+    return _irc_line_to_string(l, skip_first);
+}
+
+char *_irc_line_to_string(struct line *l, int skip_first)
 {
 	size_t len = 0;
 	int i;
@@ -83,7 +98,7 @@ char *irc_line_to_string(struct line *l)
 
 	if (l->origin)
 		len = strlen(l->origin) + 2;
-	for (i = 0; i < array_count(&l->words); i++)
+	for (i = skip_first; i < array_count(&l->words); i++)
 		len += strlen(array_get(&l->words, i)) + 1;
 	len += 1; /* remove one trailing space and add \r\n */
 	len++;	  /* last args ":" */
@@ -95,7 +110,7 @@ char *irc_line_to_string(struct line *l)
 		strcat(ret, l->origin);
 		strcat(ret, " ");
 	}
-	for (i = 0; i < array_count(&l->words) - 1; i++) {
+	for (i = skip_first; i < array_count(&l->words) - 1; i++) {
 		strcat(ret, array_get(&l->words, i));
 		strcat(ret, " ");
 	}
@@ -143,6 +158,12 @@ void irc_line_drop(struct line *line, int elem)
 	bip_cfree(array_drop(&line->words, elem));
 }
 
+int irc_line_is_error(struct line *line)
+{
+	const char *irc_code = irc_line_elem(line, 0);
+	return (irc_code[0] == '4');
+}
+
 int irc_line_elem_equals(struct line *line, int elem, const char *cmp)
 {
 	return !strcmp(irc_line_elem(line, elem), cmp);

src/line.h

@@ -90,6 +90,7 @@ void irc_line_write(struct line *l, connection_t *c);
 void irc_line_append(struct line *l, const char *s);
 struct line *irc_line_new_from_string(char *str);
 char *irc_line_to_string(struct line *l);
+char *irc_line_to_string_skip(struct line *l, int skip_first);
 char *irc_line_to_string_to(struct line *line, char *nick);
 void irc_line_free(struct line *l);
 struct line *irc_line_dup(struct line *line);
@@ -98,6 +99,7 @@ int irc_line_includes(struct line *line, int elem);
 const char *irc_line_elem(struct line *line, int elem);
 int irc_line_count(struct line *line);
 char *irc_line_pop(struct line *l);
+int irc_line_is_error(struct line *line);
 int irc_line_elem_equals(struct line *line, int elem, const char *cmp);
 int irc_line_elem_case_equals(struct line *line, int elem, const char *cmp);
 void irc_line_drop(struct line *line, int elem);