xref: /netbsd-src/usr.bin/last/want.c (revision 2980e352a13e8f0b545a366830c411e7a542ada8)
1 /*	$NetBSD: want.c,v 1.11 2007/10/05 07:27:42 lukem 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 buf[512];
46 		buf[0] = '\0';
47 		(void)sockaddr_snprintf(buf, sizeof(buf), "%a",
48 		    (struct sockaddr *)&ut->ut_ss);
49 		return buf;
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 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, *crmsg;
75 	size_t  len = sizeof(*buf) * MAXUTMP;
76 	char namebuf[sizeof(bp->ut_name) + 1], *namep;
77 	char linebuf[sizeof(bp->ut_line) + 1], *linep;
78 	char hostbuf[sizeof(bp->ut_host) + 1], *hostp;
79 	int checkname = namesz > sizeof(bp->ut_name);
80 	int checkline = linesz > sizeof(bp->ut_line);
81 	int checkhost = hostsz > sizeof(bp->ut_host);
82 
83 	if ((buf = malloc(len)) == NULL)
84 		err(EXIT_FAILURE, "Cannot allocate utmp buffer");
85 
86 	crmsg = NULL;
87 
88 	if (!strcmp(file, "-")) {
89 		wfd = STDIN_FILENO;
90 		file = "<stdin>";
91 	} else if ((wfd = open(file, O_RDONLY, 0)) < 0) {
92 		err(EXIT_FAILURE, "%s", file);
93 	}
94 
95 	if (lseek(wfd, 0, SEEK_CUR) < 0) {
96 		const char *dir;
97 		char *tfile;
98 		int tempfd;
99 		ssize_t tlen;
100 
101 		if (ESPIPE != errno) {
102 			err(EXIT_FAILURE, "lseek");
103 		}
104 		dir = getenv("TMPDIR");
105 		if (asprintf(&tfile, "%s/last.XXXXXX", dir ? dir : _PATH_TMP) == -1)
106 			err(EXIT_FAILURE, "asprintf");
107 		tempfd = mkstemp(tfile);
108 		if (tempfd < 0) {
109 			err(EXIT_FAILURE, "mkstemp");
110 		}
111 		unlink(tfile);
112 		for (;;) {
113 		   	tlen = read(wfd, buf, len);
114 			if (tlen < 0) {
115 				err(1, "%s: read", file);
116 			}
117 			if (tlen == 0) {
118 				break;
119 			}
120 			if (write(tempfd, buf, tlen) != tlen) {
121 				err(1, "%s: write", tfile);
122 			}
123 		}
124 		wfd = tempfd;
125 	}
126 
127 	if (fstat(wfd, &stb) == -1)
128 		err(EXIT_FAILURE, "%s: fstat", file);
129 	if (!S_ISREG(stb.st_mode))
130 		errx(EXIT_FAILURE, "%s: Not a regular file", file);
131 
132 	buf[FIRSTVALID].ut_timefld = time(NULL);
133 	(void)signal(SIGINT, onintr);
134 	(void)signal(SIGQUIT, onintr);
135 
136 	offset = stb.st_size;
137 	/* Ignore trailing garbage or partial record */
138 	offset -= offset % (off_t) sizeof(*buf);
139 
140 	while (offset >= (off_t) sizeof(*buf)) {
141 		ssize_t ret, i;
142 		size_t size;
143 
144 		size = MIN(len, offset);
145 		offset -= size; /* Always a multiple of sizeof(*buf) */
146 		ret = pread(wfd, buf, size, offset);
147 		if (ret < 0) {
148 			err(EXIT_FAILURE, "%s: pread", file);
149 		} else if ((size_t) ret < size) {
150 			err(EXIT_FAILURE, "%s: Unexpected end of file", file);
151 		}
152 
153 		for (i = ret / sizeof(*buf) - 1; i >= 0; i--) {
154 			bp = &buf[i];
155 
156 			NULTERM(name);
157 			NULTERM(line);
158 			NULTERM(host);
159 			/*
160 			 * if the terminal line is '~', the machine stopped.
161 			 * see utmp(5) for more info.
162 			 */
163 			if (linep[0] == '~' && !linep[1]) {
164 				/* everybody just logged out */
165 				for (T = ttylist; T; T = T->next)
166 					T->logout = -bp->ut_timefld;
167 				currentout = -bp->ut_timefld;
168 				crmsg = strncmp(namep, "shutdown",
169 				    namesz) ? "crash" : "shutdown";
170 				if (want(bp, NO)) {
171 					ct = fmttime(bp->ut_timefld, fulltime);
172 					printf("%-*.*s  %-*.*s %-*.*s %s\n",
173 					    namesz, namesz, namep,
174 					    linesz, linesz, linep,
175 					    hostsz, hostsz,
176 					    gethost(bp, hostp, numeric), ct);
177 					if (maxrec != -1 && !--maxrec)
178 						return;
179 				}
180 				continue;
181 			}
182 			/*
183 			 * if the line is '{' or '|', date got set; see
184 			 * utmp(5) for more info.
185 			 */
186 			if ((linep[0] == '{' || linep[0] == '|') && !linep[1]) {
187 				if (want(bp, NO)) {
188 					ct = fmttime(bp->ut_timefld, fulltime);
189 					printf("%-*.*s  %-*.*s %-*.*s %s\n",
190 					    namesz, namesz, namep,
191 					    linesz, linesz, linep,
192 					    hostsz, hostsz,
193 					    gethost(bp, hostp, numeric),
194 					    ct);
195 					if (maxrec && !--maxrec)
196 						return;
197 				}
198 				continue;
199 			}
200 			/* find associated tty */
201 			for (T = ttylist;; T = T->next) {
202 				if (!T) {
203 					/* add new one */
204 					T = addtty(linep);
205 					break;
206 				}
207 				if (!strncmp(T->tty, linep, LINESIZE))
208 					break;
209 			}
210 			if (TYPE(bp) == SIGNATURE)
211 				continue;
212 			if (namep[0] && want(bp, YES)) {
213 				ct = fmttime(bp->ut_timefld, fulltime);
214 				printf("%-*.*s  %-*.*s %-*.*s %s ",
215 				    namesz, namesz, namep,
216 				    linesz, linesz, linep,
217 				    hostsz, hostsz,
218 				    gethost(bp, hostp, numeric),
219 				    ct);
220 				if (!T->logout)
221 					puts("  still logged in");
222 				else {
223 					time_t	delta;			/* time difference */
224 
225 					if (T->logout < 0) {
226 						T->logout = -T->logout;
227 						printf("- %s", crmsg);
228 					}
229 					else
230 						printf("- %s",
231 						    fmttime(T->logout,
232 						    fulltime | TIMEONLY));
233 					delta = T->logout - bp->ut_timefld;
234 					if (delta < SECSPERDAY)
235 						printf("  (%s)\n",
236 						    fmttime(delta,
237 						    fulltime | TIMEONLY | GMT));
238 					else
239 						printf(" (%ld+%s)\n",
240 						    delta / SECSPERDAY,
241 						    fmttime(delta,
242 						    fulltime | TIMEONLY | GMT));
243 				}
244 				if (maxrec != -1 && !--maxrec)
245 					return;
246 			}
247 			T->logout = bp->ut_timefld;
248 		}
249 	}
250 	fulltime = 1;	/* show full time */
251 	crmsg = fmttime(buf[FIRSTVALID].ut_timefld, FULLTIME);
252 	if ((ct = strrchr(file, '/')) != NULL)
253 		ct++;
254 	printf("\n%s begins %s\n", ct ? ct : file, crmsg);
255 }
256 
257 /*
258  * want --
259  *	see if want this entry
260  */
261 static int
262 want(struct utmp *bp, int check)
263 {
264 	ARG *step;
265 
266 	if (check) {
267 		/*
268 		 * when uucp and ftp log in over a network, the entry in
269 		 * the utmp file is the name plus their process id.  See
270 		 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
271 		 */
272 		if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
273 			bp->ut_line[3] = '\0';
274 		else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
275 			bp->ut_line[4] = '\0';
276 	}
277 	if (!arglist)
278 		return (YES);
279 
280 	for (step = arglist; step; step = step->next)
281 		switch(step->type) {
282 		case HOST_TYPE:
283 			if (!strncasecmp(step->name, bp->ut_host, HOSTSIZE))
284 				return (YES);
285 			break;
286 		case TTY_TYPE:
287 			if (!strncmp(step->name, bp->ut_line, LINESIZE))
288 				return (YES);
289 			break;
290 		case USER_TYPE:
291 			if (!strncmp(step->name, bp->ut_name, NAMESIZE))
292 				return (YES);
293 			break;
294 	}
295 	return (NO);
296 }
297 
298 /*
299  * onintr --
300  *	on interrupt, we inform the user how far we've gotten
301  */
302 static void
303 onintr(int signo)
304 {
305 	/* FIXME: None of this is allowed in a signal handler */
306 	printf("\ninterrupted %s\n", fmttime(buf[FIRSTVALID].ut_timefld,
307 	    FULLTIME));
308 	if (signo == SIGINT) {
309 		(void)raise_default_signal(signo);
310 		exit(EXIT_FAILURE);
311 	}
312 	(void)fflush(stdout);		/* fix required for rsh */
313 }
314