xref: /netbsd-src/usr.bin/last/want.c (revision a5847cc334d9a7029f6352b847e9e8d71a0f9e0c)
1 /*	$NetBSD: want.c,v 1.14 2011/09/16 15:39:27 joerg Exp $	*/
2 
3 /*
4  * Copyright (c) 1987, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 static struct utmp *buf;
32 
33 static void onintr(int);
34 static int want(struct utmp *, int);
35 static const char *gethost(struct utmp *, const char *, int);
36 
37 static const char *
38 /*ARGSUSED*/
39 gethost(struct utmp *ut, const char *host, int numeric)
40 {
41 #if FIRSTVALID == 0
42 	return numeric ? "" : host;
43 #else
44 	if (numeric) {
45 		static char hbuf[512];
46 		hbuf[0] = '\0';
47 		(void)sockaddr_snprintf(hbuf, sizeof(hbuf), "%a",
48 		    (struct sockaddr *)&ut->ut_ss);
49 		return hbuf;
50 	} else
51 		return host;
52 #endif
53 }
54 
55 #define NULTERM(what) \
56 	if (check ## what) \
57 		(void)strlcpy(what ## p = what ## buf, bp->ut_ ## what, \
58 		    sizeof(what ## buf)); \
59 	else \
60 		what ## p = bp->ut_ ## what
61 
62 /*
63  * wtmp --
64  *	read through the wtmp file
65  */
66 static void
67 wtmp(const char *file, int namesz, int linesz, int hostsz, int numeric)
68 {
69 	struct utmp	*bp;		/* current structure */
70 	TTY	*T;			/* tty list entry */
71 	struct stat	stb;		/* stat of file for sz */
72 	off_t	offset;
73 	int	wfd;
74 	char	*ct;
75 	const char *crmsg;
76 	size_t  len = sizeof(*buf) * MAXUTMP;
77 	char namebuf[sizeof(bp->ut_name) + 1], *namep;
78 	char linebuf[sizeof(bp->ut_line) + 1], *linep;
79 	char hostbuf[sizeof(bp->ut_host) + 1], *hostp;
80 	int checkname = namesz > (int)sizeof(bp->ut_name);
81 	int checkline = linesz > (int)sizeof(bp->ut_line);
82 	int checkhost = hostsz > (int)sizeof(bp->ut_host);
83 
84 	if ((buf = malloc(len)) == NULL)
85 		err(EXIT_FAILURE, "Cannot allocate utmp buffer");
86 
87 	crmsg = NULL;
88 
89 	if (!strcmp(file, "-")) {
90 		wfd = STDIN_FILENO;
91 		file = "<stdin>";
92 	} else if ((wfd = open(file, O_RDONLY, 0)) < 0) {
93 		err(EXIT_FAILURE, "%s", file);
94 	}
95 
96 	if (lseek(wfd, 0, SEEK_CUR) < 0) {
97 		const char *dir;
98 		char *tfile;
99 		int tempfd;
100 		ssize_t tlen;
101 
102 		if (ESPIPE != errno) {
103 			err(EXIT_FAILURE, "lseek");
104 		}
105 		dir = getenv("TMPDIR");
106 		if (asprintf(&tfile, "%s/last.XXXXXX", dir ? dir : _PATH_TMP) == -1)
107 			err(EXIT_FAILURE, "asprintf");
108 		tempfd = mkstemp(tfile);
109 		if (tempfd < 0) {
110 			err(EXIT_FAILURE, "mkstemp");
111 		}
112 		unlink(tfile);
113 		for (;;) {
114 		   	tlen = read(wfd, buf, len);
115 			if (tlen < 0) {
116 				err(1, "%s: read", file);
117 			}
118 			if (tlen == 0) {
119 				break;
120 			}
121 			if (write(tempfd, buf, tlen) != tlen) {
122 				err(1, "%s: write", tfile);
123 			}
124 		}
125 		wfd = tempfd;
126 	}
127 
128 	if (fstat(wfd, &stb) == -1)
129 		err(EXIT_FAILURE, "%s: fstat", file);
130 	if (!S_ISREG(stb.st_mode))
131 		errx(EXIT_FAILURE, "%s: Not a regular file", file);
132 
133 	buf[FIRSTVALID].ut_timefld = time(NULL);
134 	(void)signal(SIGINT, onintr);
135 	(void)signal(SIGQUIT, onintr);
136 
137 	offset = stb.st_size;
138 	/* Ignore trailing garbage or partial record */
139 	offset -= offset % (off_t) sizeof(*buf);
140 
141 	while (offset >= (off_t) sizeof(*buf)) {
142 		ssize_t ret, i;
143 		size_t size;
144 
145 		size = MIN((off_t)len, offset);
146 		offset -= size; /* Always a multiple of sizeof(*buf) */
147 		ret = pread(wfd, buf, size, offset);
148 		if (ret < 0) {
149 			err(EXIT_FAILURE, "%s: pread", file);
150 		} else if ((size_t) ret < size) {
151 			err(EXIT_FAILURE, "%s: Unexpected end of file", file);
152 		}
153 
154 		for (i = ret / sizeof(*buf) - 1; i >= 0; i--) {
155 			bp = &buf[i];
156 
157 			NULTERM(name);
158 			NULTERM(line);
159 			NULTERM(host);
160 			/*
161 			 * if the terminal line is '~', the machine stopped.
162 			 * see utmp(5) for more info.
163 			 */
164 			if (linep[0] == '~' && !linep[1]) {
165 				/* everybody just logged out */
166 				for (T = ttylist; T; T = T->next)
167 					T->logout = -bp->ut_timefld;
168 				currentout = -bp->ut_timefld;
169 				crmsg = strncmp(namep, "shutdown",
170 				    namesz) ? "crash" : "shutdown";
171 				if (want(bp, NO)) {
172 					ct = fmttime(bp->ut_timefld, fulltime);
173 					printf("%-*.*s  %-*.*s %-*.*s %s\n",
174 					    namesz, namesz, namep,
175 					    linesz, linesz, linep,
176 					    hostsz, hostsz,
177 					    gethost(bp, hostp, numeric), ct);
178 					if (maxrec != -1 && !--maxrec)
179 						return;
180 				}
181 				continue;
182 			}
183 			/*
184 			 * if the line is '{' or '|', date got set; see
185 			 * utmp(5) for more info.
186 			 */
187 			if ((linep[0] == '{' || linep[0] == '|') && !linep[1]) {
188 				if (want(bp, NO)) {
189 					ct = fmttime(bp->ut_timefld, fulltime);
190 					printf("%-*.*s  %-*.*s %-*.*s %s\n",
191 					    namesz, namesz, namep,
192 					    linesz, linesz, linep,
193 					    hostsz, hostsz,
194 					    gethost(bp, hostp, numeric),
195 					    ct);
196 					if (maxrec && !--maxrec)
197 						return;
198 				}
199 				continue;
200 			}
201 			/* find associated tty */
202 			for (T = ttylist;; T = T->next) {
203 				if (!T) {
204 					/* add new one */
205 					T = addtty(linep);
206 					break;
207 				}
208 				if (!strncmp(T->tty, linep, LINESIZE))
209 					break;
210 			}
211 			if (TYPE(bp) == SIGNATURE)
212 				continue;
213 			if (namep[0] && want(bp, YES)) {
214 				ct = fmttime(bp->ut_timefld, fulltime);
215 				printf("%-*.*s  %-*.*s %-*.*s %s ",
216 				    namesz, namesz, namep,
217 				    linesz, linesz, linep,
218 				    hostsz, hostsz,
219 				    gethost(bp, hostp, numeric),
220 				    ct);
221 				if (!T->logout)
222 					puts("  still logged in");
223 				else {
224 					time_t	delta;			/* time difference */
225 
226 					if (T->logout < 0) {
227 						T->logout = -T->logout;
228 						printf("- %s", crmsg);
229 					}
230 					else
231 						printf("- %s",
232 						    fmttime(T->logout,
233 						    fulltime | TIMEONLY));
234 					delta = T->logout - bp->ut_timefld;
235 					if (delta < SECSPERDAY)
236 						printf("  (%s)\n",
237 						    fmttime(delta,
238 						    fulltime | TIMEONLY | GMT));
239 					else
240 						printf(" (%lld+%s)\n",
241 						    (long long)
242 						    delta / SECSPERDAY,
243 						    fmttime(delta,
244 						    fulltime | TIMEONLY | GMT));
245 				}
246 				if (maxrec != -1 && !--maxrec)
247 					return;
248 			}
249 			T->logout = bp->ut_timefld;
250 		}
251 	}
252 	fulltime = 1;	/* show full time */
253 	crmsg = fmttime(buf[FIRSTVALID].ut_timefld, FULLTIME);
254 	if ((ct = strrchr(file, '/')) != NULL)
255 		ct++;
256 	printf("\n%s begins %s\n", ct ? ct : file, crmsg);
257 }
258 
259 /*
260  * want --
261  *	see if want this entry
262  */
263 static int
264 want(struct utmp *bp, int check)
265 {
266 	ARG *step;
267 
268 	if (check) {
269 		/*
270 		 * when uucp and ftp log in over a network, the entry in
271 		 * the utmp file is the name plus their process id.  See
272 		 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
273 		 */
274 		if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
275 			bp->ut_line[3] = '\0';
276 		else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
277 			bp->ut_line[4] = '\0';
278 	}
279 	if (!arglist)
280 		return (YES);
281 
282 	for (step = arglist; step; step = step->next)
283 		switch(step->type) {
284 		case HOST_TYPE:
285 			if (!strncasecmp(step->name, bp->ut_host, HOSTSIZE))
286 				return (YES);
287 			break;
288 		case TTY_TYPE:
289 			if (!strncmp(step->name, bp->ut_line, LINESIZE))
290 				return (YES);
291 			break;
292 		case USER_TYPE:
293 			if (!strncmp(step->name, bp->ut_name, NAMESIZE))
294 				return (YES);
295 			break;
296 	}
297 	return (NO);
298 }
299 
300 /*
301  * onintr --
302  *	on interrupt, we inform the user how far we've gotten
303  */
304 static void
305 onintr(int signo)
306 {
307 	/* FIXME: None of this is allowed in a signal handler */
308 	printf("\ninterrupted %s\n", fmttime(buf[FIRSTVALID].ut_timefld,
309 	    FULLTIME));
310 	if (signo == SIGINT) {
311 		(void)raise_default_signal(signo);
312 		exit(EXIT_FAILURE);
313 	}
314 	(void)fflush(stdout);		/* fix required for rsh */
315 }
316