1 /*
2  * Copyright (c) 2021 Omar Polo <op@omarpolo.com>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include "gmid.h"
18 
19 #include <sys/types.h>
20 #include <sys/uio.h>
21 
22 #include <errno.h>
23 #include <event.h>
24 #include <imsg.h>
25 #include <netdb.h>
26 #include <stdarg.h>
27 #include <stdio.h>
28 #include <string.h>
29 #include <syslog.h>
30 
31 static struct imsgbuf parent_ibuf, child_ibuf;
32 static struct event inlog;
33 static int logfd;
34 
35 static void handle_log(int, short, void*);
36 static int logger_main(int, struct imsgbuf*);
37 
38 void
39 fatal(const char *fmt, ...)
40 {
41 	va_list ap;
42 
43 	va_start(ap, fmt);
44 
45 	if (conf.foreground) {
46 		vfprintf(stderr, fmt, ap);
47 		fprintf(stderr, "\n");
48 	} else
49 		vsyslog(LOG_DAEMON | LOG_CRIT, fmt, ap);
50 
51 	va_end(ap);
52 	exit(1);
53 }
54 
55 static inline int
56 should_log(int priority)
57 {
58 	switch (priority) {
59 	case LOG_ERR:
60 		return 1;
61 	case LOG_WARNING:
62 		return 1;
63 	case LOG_NOTICE:
64 		return conf.verbose >= 1;
65 	case LOG_INFO:
66 		return conf.verbose >= 2;
67 	case LOG_DEBUG:
68 		return conf.verbose >= 3;
69 	default:
70 		return 0;
71 	}
72 }
73 
74 static inline void
75 send_log(const char *msg, size_t len)
76 {
77 	imsg_compose(&parent_ibuf, 0, 0, 0, -1, msg, len);
78 	/* XXX: use event_once() */
79 	imsg_flush(&parent_ibuf);
80 }
81 
82 static inline void
83 vlog(int priority, struct client *c,
84     const char *fmt, va_list ap)
85 {
86 	char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV];
87 	char *fmted, *s;
88 	size_t len;
89 	int ec;
90 
91 	if (!should_log(priority))
92 		return;
93 
94 	if (c != NULL) {
95 		len = sizeof(c->addr);
96 		ec = getnameinfo((struct sockaddr*)&c->addr, len,
97 		    hbuf, sizeof(hbuf),
98 		    sbuf, sizeof(sbuf),
99 		    NI_NUMERICHOST | NI_NUMERICSERV);
100 		if (ec != 0)
101 			fatal("getnameinfo: %s", gai_strerror(ec));
102 	}
103 
104 	if (vasprintf(&fmted, fmt, ap) == -1)
105 		fatal("vasprintf: %s", strerror(errno));
106 
107         if (c == NULL)
108 		ec = asprintf(&s, "internal: %s", fmted);
109 	else
110 		ec = asprintf(&s, "%s:%s %s", hbuf, sbuf, fmted);
111 
112 	if (ec < 0)
113 		fatal("asprintf: %s", strerror(errno));
114 
115 	send_log(s, ec+1);
116 
117 	free(fmted);
118 	free(s);
119 }
120 
121 void
122 log_err(struct client *c, const char *fmt, ...)
123 {
124 	va_list ap;
125 
126 	va_start(ap, fmt);
127 	vlog(LOG_ERR, c, fmt, ap);
128 	va_end(ap);
129 }
130 
131 void
132 log_warn(struct client *c, const char *fmt, ...)
133 {
134 	va_list ap;
135 
136 	va_start(ap, fmt);
137 	vlog(LOG_WARNING, c, fmt, ap);
138 	va_end(ap);
139 }
140 
141 void
142 log_notice(struct client *c, const char *fmt, ...)
143 {
144 	va_list ap;
145 
146 	va_start(ap, fmt);
147 	vlog(LOG_NOTICE, c, fmt, ap);
148 	va_end(ap);
149 }
150 
151 void
152 log_info(struct client *c, const char *fmt, ...)
153 {
154 	va_list ap;
155 
156 	va_start(ap, fmt);
157 	vlog(LOG_INFO, c, fmt, ap);
158 	va_end(ap);
159 }
160 
161 void
162 log_debug(struct client *c, const char *fmt, ...)
163 {
164 	va_list ap;
165 
166 	va_start(ap, fmt);
167 	vlog(LOG_DEBUG, c, fmt, ap);
168 	va_end(ap);
169 }
170 
171 /* strchr, but with a bound */
172 static char *
173 gmid_strnchr(char *s, int c, size_t len)
174 {
175 	size_t i;
176 
177 	for (i = 0; i < len; ++i)
178 		if (s[i] == c)
179 			return &s[i];
180 	return NULL;
181 }
182 
183 void
184 log_request(struct client *c, char *meta, size_t l)
185 {
186 	char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV], b[GEMINI_URL_LEN];
187 	char *t, *fmted;
188 	size_t len;
189 	int ec;
190 
191 	len = sizeof(c->addr);
192 	ec = getnameinfo((struct sockaddr*)&c->addr, len,
193 	    hbuf, sizeof(hbuf),
194 	    sbuf, sizeof(sbuf),
195 	    NI_NUMERICHOST | NI_NUMERICSERV);
196 	if (ec != 0)
197 		fatal("getnameinfo: %s", gai_strerror(ec));
198 
199 	if (c->iri.schema != NULL) {
200 		/* serialize the IRI */
201 		strlcpy(b, c->iri.schema, sizeof(b));
202 		strlcat(b, "://", sizeof(b));
203 
204 		/* log the decoded host name, but if it was invalid
205 		 * use the raw one. */
206 		if (*c->domain != '\0')
207 			strlcat(b, c->domain, sizeof(b));
208 		else
209 			strlcat(b, c->iri.host, sizeof(b));
210 
211 		strlcat(b, "/", sizeof(b));
212 		strlcat(b, c->iri.path, sizeof(b)); /* TODO: sanitize UTF8 */
213 		if (*c->iri.query != '\0') {	    /* TODO: sanitize UTF8 */
214 			strlcat(b, "?", sizeof(b));
215 			strlcat(b, c->iri.query, sizeof(b));
216 		}
217 	} else {
218 		strlcpy(b, c->req, sizeof(b));
219 	}
220 
221 	if ((t = gmid_strnchr(meta, '\r', l)) == NULL)
222 		t = meta + len;
223 
224 	ec = asprintf(&fmted, "%s:%s GET %s %.*s", hbuf, sbuf, b,
225 	    (int)(t-meta), meta);
226 	if (ec < 0)
227 		err(1, "asprintf");
228 	send_log(fmted, ec+1);
229 	free(fmted);
230 }
231 
232 
233 
234 static void
235 handle_log(int fd, short ev, void *d)
236 {
237 	struct imsgbuf	*ibuf = d;
238 	struct imsg	 imsg;
239 	ssize_t		 n, datalen;
240 	char		*msg;
241 
242 	if ((n = imsg_read(ibuf)) == -1) {
243 		if (errno == EAGAIN || errno == EWOULDBLOCK)
244 			return;
245                 err(1, "imsg_read");
246 	}
247 	if (n == 0)
248 		errx(1, "connection lost?");
249 
250 	for (;;) {
251 		if ((n = imsg_get(ibuf, &imsg)) == -1)
252 			err(1, "read error");
253 		if (n == 0)
254 			return;
255 
256 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
257 		msg = imsg.data;
258 		msg[datalen] = '\0';
259 
260 		/* ignore imsg.hdr.type for now */
261 		if (conf.foreground)
262 			fprintf(stderr, "%s\n", msg);
263 		else
264 			syslog(LOG_DAEMON, "%s", msg);
265 
266 		imsg_free(&imsg);
267 	}
268 }
269 
270 static int
271 logger_main(int fd, struct imsgbuf *ibuf)
272 {
273 	event_init();
274 
275 	event_set(&inlog, fd, EV_READ | EV_PERSIST, &handle_log, ibuf);
276 	event_add(&inlog, NULL);
277 
278 #ifdef __OpenBSD__
279 	if (pledge("stdio", NULL) == -1)
280 		err(1, "pledge");
281 #endif
282 
283 	event_dispatch();
284 
285 	return 0;
286 }
287 
288 void
289 logger_init(void)
290 {
291 	int p[2];
292 
293 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, p) == -1)
294 		err(1, "socketpair");
295 
296 	switch (fork()) {
297 	case -1:
298 		err(1, "fork");
299 	case 0:
300 		logfd = p[1];
301 		close(p[0]);
302 		setproctitle("logger");
303 		imsg_init(&child_ibuf, p[1]);
304 		drop_priv();
305 		_exit(logger_main(p[1], &child_ibuf));
306 	default:
307 		logfd = p[0];
308 		close(p[1]);
309 		imsg_init(&parent_ibuf, p[0]);
310 		return;
311 	}
312 }