1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1980, 1993 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 32 #ifndef lint 33 static const char copyright[] = 34 "@(#) Copyright (c) 1980, 1993\n\ 35 The Regents of the University of California. All rights reserved.\n"; 36 #endif /* not lint */ 37 38 #ifndef lint 39 #if 0 40 static char sccsid[] = "@(#)comsat.c 8.1 (Berkeley) 6/4/93"; 41 #endif 42 static const char rcsid[] = 43 "$FreeBSD$"; 44 #endif /* not lint */ 45 46 #include <sys/param.h> 47 #include <sys/socket.h> 48 #include <sys/stat.h> 49 #include <sys/file.h> 50 #include <sys/wait.h> 51 52 #include <netinet/in.h> 53 54 #include <ctype.h> 55 #include <err.h> 56 #include <errno.h> 57 #include <netdb.h> 58 #include <paths.h> 59 #include <pwd.h> 60 #include <termios.h> 61 #include <signal.h> 62 #include <stdio.h> 63 #include <stdlib.h> 64 #include <string.h> 65 #include <syslog.h> 66 #include <unistd.h> 67 #include <utmpx.h> 68 69 static int debug = 0; 70 #define dsyslog if (debug) syslog 71 72 #define MAXIDLE 120 73 74 static char hostname[MAXHOSTNAMELEN]; 75 76 static void jkfprintf(FILE *, char[], char[], off_t); 77 static void mailfor(char *); 78 static void notify(struct utmpx *, char[], off_t, int); 79 static void reapchildren(int); 80 81 int 82 main(int argc __unused, char *argv[] __unused) 83 { 84 struct sockaddr_in from; 85 socklen_t fromlen; 86 int cc; 87 char msgbuf[256]; 88 89 /* verify proper invocation */ 90 fromlen = sizeof(from); 91 if (getsockname(0, (struct sockaddr *)&from, &fromlen) < 0) 92 err(1, "getsockname"); 93 openlog("comsat", LOG_PID, LOG_DAEMON); 94 if (chdir(_PATH_MAILDIR)) { 95 syslog(LOG_ERR, "chdir: %s: %m", _PATH_MAILDIR); 96 (void) recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 97 exit(1); 98 } 99 (void)gethostname(hostname, sizeof(hostname)); 100 (void)signal(SIGTTOU, SIG_IGN); 101 (void)signal(SIGCHLD, reapchildren); 102 for (;;) { 103 cc = recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 104 if (cc <= 0) { 105 if (errno != EINTR) 106 sleep(1); 107 errno = 0; 108 continue; 109 } 110 msgbuf[cc] = '\0'; 111 mailfor(msgbuf); 112 sigsetmask(0L); 113 } 114 } 115 116 static void 117 reapchildren(int signo __unused) 118 { 119 while (wait3(NULL, WNOHANG, NULL) > 0); 120 } 121 122 static void 123 mailfor(char *name) 124 { 125 struct utmpx *utp; 126 char *cp; 127 char *file; 128 off_t offset; 129 int folder; 130 char buf[sizeof(_PATH_MAILDIR) + sizeof(utp->ut_user) + 1]; 131 char buf2[sizeof(_PATH_MAILDIR) + sizeof(utp->ut_user) + 1]; 132 133 if (!(cp = strchr(name, '@'))) 134 return; 135 *cp = '\0'; 136 offset = strtoll(cp + 1, NULL, 10); 137 if (!(cp = strchr(cp + 1, ':'))) 138 file = name; 139 else 140 file = cp + 1; 141 sprintf(buf, "%s/%.*s", _PATH_MAILDIR, (int)sizeof(utp->ut_user), 142 name); 143 if (*file != '/') { 144 sprintf(buf2, "%s/%.*s", _PATH_MAILDIR, 145 (int)sizeof(utp->ut_user), file); 146 file = buf2; 147 } 148 folder = strcmp(buf, file); 149 setutxent(); 150 while ((utp = getutxent()) != NULL) 151 if (utp->ut_type == USER_PROCESS && !strcmp(utp->ut_user, name)) 152 notify(utp, file, offset, folder); 153 endutxent(); 154 } 155 156 static const char *cr; 157 158 static void 159 notify(struct utmpx *utp, char file[], off_t offset, int folder) 160 { 161 FILE *tp; 162 struct stat stb; 163 struct termios tio; 164 char tty[20]; 165 const char *s = utp->ut_line; 166 167 if (strncmp(s, "pts/", 4) == 0) 168 s += 4; 169 if (strchr(s, '/')) { 170 /* A slash is an attempt to break security... */ 171 syslog(LOG_AUTH | LOG_NOTICE, "Unexpected `/' in `%s'", 172 utp->ut_line); 173 return; 174 } 175 (void)snprintf(tty, sizeof(tty), "%s%.*s", 176 _PATH_DEV, (int)sizeof(utp->ut_line), utp->ut_line); 177 if (stat(tty, &stb) == -1 || !(stb.st_mode & (S_IXUSR | S_IXGRP))) { 178 dsyslog(LOG_DEBUG, "%s: wrong mode on %s", utp->ut_user, tty); 179 return; 180 } 181 dsyslog(LOG_DEBUG, "notify %s on %s", utp->ut_user, tty); 182 switch (fork()) { 183 case -1: 184 syslog(LOG_NOTICE, "fork failed (%m)"); 185 return; 186 case 0: 187 break; 188 default: 189 return; 190 } 191 if ((tp = fopen(tty, "w")) == NULL) { 192 dsyslog(LOG_ERR, "%s: %s", tty, strerror(errno)); 193 _exit(1); 194 } 195 (void)tcgetattr(fileno(tp), &tio); 196 cr = ((tio.c_oflag & (OPOST|ONLCR)) == (OPOST|ONLCR)) ? "\n" : "\n\r"; 197 switch (stb.st_mode & (S_IXUSR | S_IXGRP)) { 198 case S_IXUSR: 199 case (S_IXUSR | S_IXGRP): 200 (void)fprintf(tp, 201 "%s\007New mail for %s@%.*s\007 has arrived%s%s%s:%s----%s", 202 cr, utp->ut_user, (int)sizeof(hostname), hostname, 203 folder ? cr : "", folder ? "to " : "", folder ? file : "", 204 cr, cr); 205 jkfprintf(tp, utp->ut_user, file, offset); 206 break; 207 case S_IXGRP: 208 (void)fprintf(tp, "\007"); 209 (void)fflush(tp); 210 (void)sleep(1); 211 (void)fprintf(tp, "\007"); 212 break; 213 default: 214 break; 215 } 216 (void)fclose(tp); 217 _exit(0); 218 } 219 220 static void 221 jkfprintf(FILE *tp, char user[], char file[], off_t offset) 222 { 223 unsigned char *cp, ch; 224 FILE *fi; 225 int linecnt, charcnt, inheader; 226 struct passwd *p; 227 unsigned char line[BUFSIZ]; 228 229 /* Set effective uid to user in case mail drop is on nfs */ 230 if ((p = getpwnam(user)) != NULL) 231 (void) setuid(p->pw_uid); 232 233 if ((fi = fopen(file, "r")) == NULL) 234 return; 235 236 (void)fseeko(fi, offset, SEEK_CUR); 237 /* 238 * Print the first 7 lines or 560 characters of the new mail 239 * (whichever comes first). Skip header crap other than 240 * From, Subject, To, and Date. 241 */ 242 linecnt = 7; 243 charcnt = 560; 244 inheader = 1; 245 while (fgets(line, sizeof(line), fi) != NULL) { 246 if (inheader) { 247 if (line[0] == '\n') { 248 inheader = 0; 249 continue; 250 } 251 if (line[0] == ' ' || line[0] == '\t' || 252 (strncmp(line, "From:", 5) && 253 strncmp(line, "Subject:", 8))) 254 continue; 255 } 256 if (linecnt <= 0 || charcnt <= 0) { 257 (void)fprintf(tp, "...more...%s", cr); 258 (void)fclose(fi); 259 return; 260 } 261 /* strip weird stuff so can't trojan horse stupid terminals */ 262 for (cp = line; (ch = *cp) && ch != '\n'; ++cp, --charcnt) { 263 /* disable upper controls and enable all other 264 8bit codes due to lack of locale knowledge 265 */ 266 if (((ch & 0x80) && ch < 0xA0) || 267 (!(ch & 0x80) && !isprint(ch) && 268 !isspace(ch) && ch != '\a' && ch != '\b') 269 ) { 270 if (ch & 0x80) { 271 ch &= ~0x80; 272 (void)fputs("M-", tp); 273 } 274 if (iscntrl(ch)) { 275 ch ^= 0x40; 276 (void)fputc('^', tp); 277 } 278 } 279 (void)fputc(ch, tp); 280 } 281 (void)fputs(cr, tp); 282 --linecnt; 283 } 284 (void)fprintf(tp, "----%s\n", cr); 285 (void)fclose(fi); 286 } 287