1 /*
2  * Copyright (c) 2023 Omar Polo <op@openbsd.org>
3  * Copyright (c) 2003-2004 Daniel Hartmeier
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  *    - Redistributions of source code must retain the above copyright
11  *      notice, this list of conditions and the following disclaimer.
12  *    - Redistributions in binary form must reproduce the above
13  *      copyright notice, this list of conditions and the following
14  *      disclaimer in the documentation and/or other materials provided
15  *      with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
20  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
21  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
23  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
24  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
25  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
27  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGE.
29  *
30  */
31 
32 #include <err.h>
33 #include <stdarg.h>
34 #include <stdio.h>
35 #include <string.h>
36 
37 #include "irc.h"
38 #include "icb.h"
39 
40 extern void	 scan(const char **, char *, size_t, const char *,
41 		    const char *);
42 extern void	 icbirc_quit(void);
43 extern int	 sync_write(int, const char *, int);
44 
45 static void	 irc_cmd(char *, int, int);
46 
47 static void	 irc_send_pong(int, const char *);
48 
49 char irc_pass[256];
50 char irc_ident[256];
51 char irc_nick[256];
52 char irc_channel[256];
53 int in_irc_channel;
54 int in_cap;
55 
56 /*
57  * irc_recv() receives read(2) chunks and assembles complete lines, which are
58  * passed to irc_cmd(). Overlong lines are truncated after 65kB.
59  *
60  * XXX: argument checking is not as strong as for ICB (trusting the client)
61  *
62  */
63 
64 void
65 irc_recv(const char *buf, unsigned len, int client_fd, int server_fd)
66 {
67 	static char cmd[65535];
68 	static unsigned off = 0;
69 
70 	while (len > 0) {
71 		while (len > 0 && off < (sizeof(cmd) - 1) && *buf != '\n') {
72 			cmd[off++] = *buf++;
73 			len--;
74 		}
75 		if (off == (sizeof(cmd) - 1))
76 			while (len > 0 && *buf != '\n') {
77 				buf++;
78 				len--;
79 			}
80 		/* off <= sizeof(cmd) - 1 */
81 		if (len > 0 && *buf == '\n') {
82 			buf++;
83 			len--;
84 			if (off > 0 && cmd[off - 1] == '\r')
85 				cmd[off - 1] = 0;
86 			else
87 				cmd[off] = 0;
88 			irc_cmd(cmd, client_fd, server_fd);
89 			off = 0;
90 		}
91 	}
92 }
93 
94 static void
95 irc_complete_registration(int server_fd)
96 {
97 	if (icb_logged_in || *irc_nick == '\0' || *irc_ident == '\0')
98 		return;
99 	if (in_cap)
100 		return;
101 	icb_send_login(server_fd, irc_nick, irc_ident, irc_pass);
102 }
103 
104 static void
105 irc_cmd(char *cmd, int client_fd, int server_fd)
106 {
107 	char *argv[10], *p;
108 	int argc = 1;
109 
110 	if (!strncasecmp(cmd, "RAWICB ", 7)) {
111 		icb_send_raw(server_fd, cmd + 7);
112 		return;
113 	}
114 
115 	for (p = cmd, argv[0] = p; argc < 10 && (p = strchr(p, ' ')) != NULL;
116 	    argc++) {
117 		*p++ = '\0';
118 		while (*p == ' ')
119 			p++;
120 		if (*p == ':') {
121 			argv[argc] = p + 1;
122 			argc++;
123 			break;
124 		}
125 		argv[argc] = p;
126 	}
127 
128 	if (!strcasecmp(argv[0], "PASS")) {
129 		strlcpy(irc_pass, argv[1], sizeof(irc_pass));
130 	} else if (!strcasecmp(argv[0], "USER")) {
131 		strlcpy(irc_ident, argv[1], sizeof(irc_ident));
132 		irc_complete_registration(server_fd);
133 	} else if (!strcasecmp(argv[0], "NICK")) {
134 		strlcpy(irc_nick, argv[1], sizeof(irc_nick));
135 		if (icb_logged_in)
136 			icb_send_name(server_fd, irc_nick);
137 		else if (irc_nick[0] && irc_ident[0])
138 			icb_send_login(server_fd, irc_nick,
139 			    irc_ident, irc_pass);
140 	} else if (!strcasecmp(argv[0], "JOIN")) {
141 		icb_send_group(server_fd,
142 		    argv[1] + (argv[1][0] == '#' ? 1 : 0));
143 	} else if (!strcasecmp(argv[0], "PART")) {
144 		in_irc_channel = 0;
145 	} else if (!strcasecmp(argv[0], "PRIVMSG") ||
146 	    !strcasecmp(argv[0], "NOTICE")) {
147 		char msg[8192];
148 		unsigned i, j;
149 
150 		strlcpy(msg, argv[2], sizeof(msg));
151 		/* strip \001 found in CTCP messages */
152 		i = 0;
153 		while (msg[i]) {
154 			if (msg[i] == '\001') {
155 				for (j = i; msg[j + 1]; ++j)
156 					msg[j] = msg[j + 1];
157 				msg[j] = 0;
158 			} else
159 				i++;
160 		}
161 		if (!strcmp(argv[1], irc_channel))
162 			icb_send_openmsg(server_fd, msg);
163 		else
164 			icb_send_privmsg(server_fd, argv[1], msg);
165 	} else if (!strcasecmp(argv[0], "MODE")) {
166 		if (strcmp(argv[1], irc_channel))
167 			return;
168 		if (argc == 2)
169 			icb_send_names(server_fd, irc_channel);
170 		else {
171 			if (strcmp(argv[2], "+o")) {
172 				warnx("irc_cmd: invalid MODE args '%s'",
173 				    argv[2]);
174 				return;
175 			}
176 			icb_send_pass(server_fd, argv[3]);
177 		}
178 	} else if (!strcasecmp(argv[0], "TOPIC")) {
179 		if (strcmp(argv[1], irc_channel)) {
180 			warnx("irc_cmd: invalid TOPIC channel '%s'",
181 			    argv[1]);
182 			return;
183 		}
184 		icb_send_topic(server_fd, argv[2]);
185 	} else if (!strcasecmp(argv[0], "LIST")) {
186 		icb_send_list(server_fd);
187 	} else if (!strcasecmp(argv[0], "NAMES")) {
188 		icb_send_names(server_fd, argv[1]);
189 	} else if (!strcasecmp(argv[0], "WHOIS")) {
190 		icb_send_whois(server_fd, argv[1]);
191 	} else if (!strcasecmp(argv[0], "WHO")) {
192 		icb_send_who(server_fd, argv[1]);
193 	} else if (!strcasecmp(argv[0], "KICK")) {
194 		if (strcmp(argv[1], irc_channel)) {
195 			warnx("irc_cmd: invalid KICK args '%s'", argv[1]);
196 			return;
197 		}
198 		icb_send_boot(server_fd, argv[2]);
199 	} else if (!strcasecmp(argv[0], "PING")) {
200 		icb_send_noop(server_fd);
201 		irc_send_pong(client_fd, argv[1]);
202 	} else if (!strcasecmp(argv[0], "QUIT")) {
203 		warnx("client QUIT");
204 		icbirc_quit();
205 	} else if (!strcasecmp(argv[0], "CAP")) {
206 		if (!strcasecmp(argv[1], "LS")) {
207 			in_cap = 1;
208 			printf("CAP * LS :\n");
209 			fflush(stdout);
210 		} else if (!strcasecmp(argv[1], "REQ")) {
211 			in_cap = 1;
212 			printf("CAP * NAK :%s\n", argv[2]);
213 			fflush(stdout);
214 		} else if (!strcasecmp(argv[1], "END")) {
215 			in_cap = 0;
216 			irc_complete_registration(server_fd);
217 		} else
218 			warnx("irc_cmd: unknown command 'CAP %s'", argv[1]);
219 	} else
220 		warnx("irc_cmd: unknown command '%s'", argv[0]);
221 }
222 
223 void
224 irc_send_notice(int fd, const char *format, ...)
225 {
226 	char cmd[8192], msg[8192];
227 	va_list ap;
228 
229 	va_start(ap, format);
230 	vsnprintf(msg, sizeof(msg), format, ap);
231 	va_end(ap);
232 	snprintf(cmd, sizeof(cmd), "NOTICE %s\r\n", msg);
233 	sync_write(fd, cmd, strlen(cmd));
234 }
235 
236 void
237 irc_send_code(int fd, const char *from, const char *nick, const char *code,
238     const char *format, ...)
239 {
240 	char cmd[8192], msg[8192];
241 	va_list ap;
242 
243 	va_start(ap, format);
244 	vsnprintf(msg, sizeof(msg), format, ap);
245 	va_end(ap);
246 	snprintf(cmd, sizeof(cmd), ":%s %s %s :%s\r\n", from, code, nick, msg);
247 	sync_write(fd, cmd, strlen(cmd));
248 }
249 
250 void
251 irc_send_msg(int fd, const char *src, const char *dst, const char *msg)
252 {
253 	char cmd[8192];
254 
255 	snprintf(cmd, sizeof(cmd), ":%s PRIVMSG %s :%s\r\n", src, dst, msg);
256 	sync_write(fd, cmd, strlen(cmd));
257 }
258 
259 void
260 irc_send_join(int fd, const char *src, const char *dst)
261 {
262 	char cmd[8192];
263 
264 	snprintf(cmd, sizeof(cmd), ":%s JOIN :%s\r\n", src, dst);
265 	sync_write(fd, cmd, strlen(cmd));
266 	in_irc_channel = 1;
267 }
268 
269 void
270 irc_send_part(int fd, const char *src, const char *dst)
271 {
272 	char cmd[8192];
273 
274 	snprintf(cmd, sizeof(cmd), ":%s PART :%s\r\n", src, dst);
275 	sync_write(fd, cmd, strlen(cmd));
276 }
277 
278 void
279 irc_send_pong(int fd, const char *daemon)
280 {
281 	char cmd[8192];
282 
283 	snprintf(cmd, sizeof(cmd), "PONG %s\r\n", daemon);
284 	sync_write(fd, cmd, strlen(cmd));
285 }