1 /* $NetBSD: utmpentry.c,v 1.16 2008/10/28 14:01:46 christos Exp $ */
2
3 /*-
4 * Copyright (c) 2002 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Christos Zoulas.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 #include <sys/stat.h>
34
35 #include <err.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <time.h>
40 #include <utmpx.h>
41
42 #include "utmpentry.h"
43
44 /* Operations on timespecs. */
45 #define timespec2ns(x) (((uint64_t)(x)->tv_sec) * 1000000000L + (x)->tv_nsec)
46
47
48 #define COMPILE_ASSERT(x) _Static_assert(x, "assertion failed")
49
50
51 static void getentryx(struct utmpentry *, struct utmpx *);
52 static struct timespec utmpxtime = {0, 0};
53 static int setup(const char *);
54 static void adjust_size(struct utmpentry *e);
55
56 int maxname = 8, maxline = 8, maxhost = 16;
57 int etype = 1 << USER_PROCESS;
58 static int numutmp = 0;
59 static struct utmpentry *ehead;
60
61 static void
adjust_size(struct utmpentry * e)62 adjust_size(struct utmpentry *e)
63 {
64 int max;
65
66 if ((max = strlen(e->name)) > maxname)
67 maxname = max;
68 if ((max = strlen(e->line)) > maxline)
69 maxline = max;
70 if ((max = strlen(e->host)) > maxhost)
71 maxhost = max;
72 }
73
74 static int
setup(const char * fname)75 setup(const char *fname)
76 {
77 int what = 3;
78 struct stat st;
79 const char *sfname;
80
81 if (fname == NULL) {
82 setutxent();
83 } else {
84 size_t len = strlen(fname);
85 if (len == 0)
86 errx(1, "Filename cannot be 0 length.");
87 what = fname[len - 1] == 'x' ? 1 : 2;
88 if (what == 1) {
89 if (utmpxname(fname) == 0)
90 warnx("Cannot set utmpx file to `%s'",
91 fname);
92 }
93 }
94 if (what & 1) {
95 sfname = fname ? fname : _PATH_UTMPX;
96 if (stat(sfname, &st) == -1) {
97 warn("Cannot stat `%s'", sfname);
98 what &= ~1;
99 } else {
100 if (timespeccmp(&st.st_mtimespec, &utmpxtime, >))
101 utmpxtime = st.st_mtimespec;
102 else
103 what &= ~1;
104 }
105 }
106 return what;
107 }
108
109 void
endutentries(void)110 endutentries(void)
111 {
112 struct utmpentry *ep;
113
114 timespecclear(&utmpxtime);
115 ep = ehead;
116 while (ep) {
117 struct utmpentry *sep = ep;
118 ep = ep->next;
119 free(sep);
120 }
121 ehead = NULL;
122 numutmp = 0;
123 }
124
125 int
getutentries(const char * fname,struct utmpentry ** epp)126 getutentries(const char *fname, struct utmpentry **epp)
127 {
128 struct utmpx *utx;
129 struct utmpentry *ep;
130 int what = setup(fname);
131 struct utmpentry **nextp = &ehead;
132 switch (what) {
133 case 0:
134 /* No updates */
135 *epp = ehead;
136 return numutmp;
137 default:
138 /* Need to re-scan */
139 ehead = NULL;
140 numutmp = 0;
141 }
142
143 while ((what & 1) && (utx = getutxent()) != NULL) {
144 if (fname == NULL && ((1 << utx->ut_type) & etype) == 0) {
145 continue;
146 }
147 if ((ep = calloc(1, sizeof(struct utmpentry))) == NULL) {
148 warn(NULL);
149 return 0;
150 }
151 getentryx(ep, utx);
152 *nextp = ep;
153 nextp = &(ep->next);
154 }
155
156 numutmp = 0;
157 if (ehead != NULL) {
158 struct utmpentry *from = ehead, *save;
159
160 ehead = NULL;
161 while (from != NULL) {
162 for (nextp = &ehead;
163 (*nextp) && strcmp(from->line, (*nextp)->line) > 0;
164 nextp = &(*nextp)->next)
165 continue;
166 save = from;
167 from = from->next;
168 save->next = *nextp;
169 *nextp = save;
170 numutmp++;
171 }
172 }
173 *epp = ehead;
174 return numutmp;
175 }
176
177 static void
getentryx(struct utmpentry * e,struct utmpx * up)178 getentryx(struct utmpentry *e, struct utmpx *up)
179 {
180 COMPILE_ASSERT(sizeof(e->name) > sizeof(up->ut_name));
181 COMPILE_ASSERT(sizeof(e->line) > sizeof(up->ut_line));
182 COMPILE_ASSERT(sizeof(e->host) > sizeof(up->ut_host));
183
184 /*
185 * e has just been calloc'd. We don't need to clear it or
186 * append null-terminators, because its length is strictly
187 * greater than the source string. Use strncpy to _read_
188 * up->ut_* because they may not be terminated. For this
189 * reason we use the size of the _source_ as the length
190 * argument.
191 */
192 snprintf(e->name, sizeof(e->name), "%.*s",
193 (int)sizeof(up->ut_name), up->ut_name);
194 snprintf(e->line, sizeof(e->line), "%.*s",
195 (int)sizeof(up->ut_line), up->ut_line);
196 snprintf(e->host, sizeof(e->host), "%.*s",
197 (int)sizeof(up->ut_host), up->ut_host);
198
199 e->tv = up->ut_tv;
200 e->pid = up->ut_pid;
201 e->term = up->ut_exit.e_termination;
202 e->exit = up->ut_exit.e_exit;
203 e->sess = up->ut_session;
204 e->type = up->ut_type;
205 adjust_size(e);
206 }
207