Annotation of src/usr.bin/login/failedlogin.c, Revision 1.17
1.17 ! deraadt 1: /* $OpenBSD: failedlogin.c,v 1.16 2013/06/01 21:06:39 deraadt Exp $ */
1.1 millert 2:
3: /*
4: * Copyright (c) 1996 Todd C. Miller <Todd.Miller@courtesan.com>
5: *
1.13 millert 6: * Permission to use, copy, modify, and distribute this software for any
7: * purpose with or without fee is hereby granted, provided that the above
8: * copyright notice and this permission notice appear in all copies.
1.1 millert 9: *
1.14 millert 10: * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16: * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
1.1 millert 17: */
18:
19: /*
20: * failedlogin.c
21: * Log to failedlogin file and read from it, reporting the number of
22: * failed logins since the last good login and when/from where
23: * the last failed login was.
24: */
25:
26: #include <sys/stat.h>
27: #include <sys/time.h>
28:
1.7 millert 29: #include <fcntl.h>
1.1 millert 30: #include <stdio.h>
31: #include <string.h>
32: #include <unistd.h>
33: #include <utmp.h>
34:
35: #include "pathnames.h"
36:
37: struct badlogin {
38: char bl_line[UT_LINESIZE]; /* tty used */
1.2 millert 39: char bl_name[UT_NAMESIZE]; /* remote username */
1.1 millert 40: char bl_host[UT_HOSTSIZE]; /* remote host */
1.2 millert 41: time_t bl_time; /* time of the login attempt */
42: size_t count; /* number of bad logins */
1.1 millert 43: };
1.10 pvalchev 44:
1.11 millert 45: void log_failedlogin(uid_t, char *, char *, char *);
46: int check_failedlogin(uid_t);
1.1 millert 47:
48: /*
49: * Log a bad login to the failedlogin file.
50: */
51: void
1.12 deraadt 52: log_failedlogin(uid_t uid, char *host, char *name, char *tty)
1.1 millert 53: {
54: struct badlogin failedlogin;
55: int fd;
56:
57: /* Add O_CREAT if you want to create failedlogin if it doesn't exist */
1.16 deraadt 58: if ((fd = open(_PATH_FAILEDLOGIN, O_RDWR, S_IRUSR|S_IWUSR)) >= 0) {
1.5 millert 59: (void)lseek(fd, (off_t)uid * sizeof(failedlogin), SEEK_SET);
1.1 millert 60:
61: /* Read in last bad login so can get the count */
62: if (read(fd, (char *)&failedlogin, sizeof(failedlogin)) !=
63: sizeof(failedlogin) || failedlogin.bl_time == 0)
64: memset((void *)&failedlogin, 0, sizeof(failedlogin));
65:
1.5 millert 66: (void)lseek(fd, (off_t)uid * sizeof(failedlogin), SEEK_SET);
1.1 millert 67: /* Increment count of bad logins */
68: ++failedlogin.count;
69: (void)time(&failedlogin.bl_time);
70: strncpy(failedlogin.bl_line, tty, sizeof(failedlogin.bl_line));
71: if (host)
72: strncpy(failedlogin.bl_host, host, sizeof(failedlogin.bl_host));
73: else
74: *failedlogin.bl_host = '\0'; /* NULL host field */
1.2 millert 75: if (name)
76: strncpy(failedlogin.bl_name, name, sizeof(failedlogin.bl_name));
77: else
78: *failedlogin.bl_name = '\0'; /* NULL name field */
1.1 millert 79: (void)write(fd, (char *)&failedlogin, sizeof(failedlogin));
80: (void)close(fd);
81: }
82: }
83:
84: /*
85: * Check the failedlogin file and report about the number of unsuccessful
86: * logins and info about the last one in lastlogin style.
87: * NOTE: zeros the count field since this is assumed to be called after the
88: * user has been validated.
89: */
90: int
1.12 deraadt 91: check_failedlogin(uid_t uid)
1.1 millert 92: {
93: struct badlogin failedlogin;
1.12 deraadt 94: int fd, was_bad = 0;
1.1 millert 95:
96: (void)memset((void *)&failedlogin, 0, sizeof(failedlogin));
97:
98: if ((fd = open(_PATH_FAILEDLOGIN, O_RDWR, 0)) >= 0) {
1.5 millert 99: (void)lseek(fd, (off_t)uid * sizeof(failedlogin), SEEK_SET);
1.1 millert 100: if (read(fd, (char *)&failedlogin, sizeof(failedlogin)) ==
101: sizeof(failedlogin) && failedlogin.count > 0 ) {
102: /* There was a bad login */
103: was_bad = 1;
104: if (failedlogin.count > 1)
1.9 millert 105: (void)printf("There have been %lu unsuccessful "
106: "login attempts to your account.\n",
107: (u_long)failedlogin.count);
1.6 pjanzen 108: (void)printf("Last unsuccessful login: %.*s", 24-5,
1.1 millert 109: (char *)ctime(&failedlogin.bl_time));
110: (void)printf(" on %.*s",
111: (int)sizeof(failedlogin.bl_line),
1.12 deraadt 112: failedlogin.bl_line);
1.3 art 113: if (*failedlogin.bl_host != '\0') {
1.2 millert 114: if (*failedlogin.bl_name != '\0')
115: (void)printf(" from %.*s@%.*s",
116: (int)sizeof(failedlogin.bl_name),
117: failedlogin.bl_name,
118: (int)sizeof(failedlogin.bl_host),
119: failedlogin.bl_host);
120: else
121: (void)printf(" from %.*s",
122: (int)sizeof(failedlogin.bl_host),
123: failedlogin.bl_host);
1.3 art 124: }
1.1 millert 125: (void)putchar('\n');
126:
127: /* Reset since this is a good login and write record */
128: failedlogin.count = 0;
1.5 millert 129: (void)lseek(fd, (off_t)uid * sizeof(failedlogin),
130: SEEK_SET);
131: (void)write(fd, (char *)&failedlogin,
132: sizeof(failedlogin));
1.1 millert 133: }
134: (void)close(fd);
135: }
136: return(was_bad);
137: }