1 /* 2 * Copyright (c) 1980, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #ifndef lint 35 static const char copyright[] = 36 "@(#) Copyright (c) 1980, 1993\n\ 37 The Regents of the University of California. All rights reserved.\n"; 38 #endif /* not lint */ 39 40 #ifndef lint 41 #if 0 42 static char sccsid[] = "@(#)comsat.c 8.1 (Berkeley) 6/4/93"; 43 #endif 44 static const char rcsid[] = 45 "$FreeBSD$"; 46 #endif /* not lint */ 47 48 #include <sys/param.h> 49 #include <sys/socket.h> 50 #include <sys/stat.h> 51 #include <sys/file.h> 52 #include <sys/wait.h> 53 54 #include <netinet/in.h> 55 56 #include <ctype.h> 57 #include <err.h> 58 #include <errno.h> 59 #include <netdb.h> 60 #include <paths.h> 61 #include <pwd.h> 62 #include <termios.h> 63 #include <signal.h> 64 #include <stdio.h> 65 #include <stdlib.h> 66 #include <string.h> 67 #include <syslog.h> 68 #include <unistd.h> 69 #include <utmp.h> 70 71 int debug = 0; 72 #define dsyslog if (debug) syslog 73 74 #define MAXIDLE 120 75 76 char hostname[MAXHOSTNAMELEN]; 77 struct utmp *utmp = NULL; 78 time_t lastmsgtime; 79 int nutmp, uf; 80 81 void jkfprintf(FILE *, char[], char[], off_t); 82 void mailfor(char *); 83 void notify(struct utmp *, char[], off_t, int); 84 void onalrm(int); 85 void reapchildren(int); 86 87 int 88 main(int argc, char *argv[]) 89 { 90 struct sockaddr_in from; 91 int cc; 92 int fromlen; 93 char msgbuf[256]; 94 95 /* verify proper invocation */ 96 fromlen = sizeof(from); 97 if (getsockname(0, (struct sockaddr *)&from, &fromlen) < 0) 98 err(1, "getsockname"); 99 openlog("comsat", LOG_PID, LOG_DAEMON); 100 if (chdir(_PATH_MAILDIR)) { 101 syslog(LOG_ERR, "chdir: %s: %m", _PATH_MAILDIR); 102 (void) recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 103 exit(1); 104 } 105 if ((uf = open(_PATH_UTMP, O_RDONLY, 0)) < 0) { 106 syslog(LOG_ERR, "open: %s: %m", _PATH_UTMP); 107 (void) recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 108 exit(1); 109 } 110 (void)time(&lastmsgtime); 111 (void)gethostname(hostname, sizeof(hostname)); 112 onalrm(0); 113 (void)signal(SIGALRM, onalrm); 114 (void)signal(SIGTTOU, SIG_IGN); 115 (void)signal(SIGCHLD, reapchildren); 116 for (;;) { 117 cc = recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 118 if (cc <= 0) { 119 if (errno != EINTR) 120 sleep(1); 121 errno = 0; 122 continue; 123 } 124 if (!nutmp) /* no one has logged in yet */ 125 continue; 126 sigblock(sigmask(SIGALRM)); 127 msgbuf[cc] = '\0'; 128 (void)time(&lastmsgtime); 129 mailfor(msgbuf); 130 sigsetmask(0L); 131 } 132 } 133 134 void 135 reapchildren(int signo) 136 { 137 while (wait3(NULL, WNOHANG, NULL) > 0); 138 } 139 140 void 141 onalrm(int signo) 142 { 143 static u_int utmpsize; /* last malloced size for utmp */ 144 static u_int utmpmtime; /* last modification time for utmp */ 145 struct stat statbf; 146 147 if (time(NULL) - lastmsgtime >= MAXIDLE) 148 exit(0); 149 (void)alarm((u_int)15); 150 (void)fstat(uf, &statbf); 151 if (statbf.st_mtime > utmpmtime) { 152 utmpmtime = statbf.st_mtime; 153 if (statbf.st_size > utmpsize) { 154 utmpsize = statbf.st_size + 10 * sizeof(struct utmp); 155 if ((utmp = realloc(utmp, utmpsize)) == NULL) { 156 syslog(LOG_ERR, "%s", strerror(errno)); 157 exit(1); 158 } 159 } 160 (void)lseek(uf, (off_t)0, SEEK_SET); 161 nutmp = read(uf, utmp, (size_t)statbf.st_size)/sizeof(struct utmp); 162 } 163 } 164 165 void 166 mailfor(char *name) 167 { 168 struct utmp *utp = &utmp[nutmp]; 169 char *cp; 170 char *file; 171 off_t offset; 172 int folder; 173 char buf[sizeof(_PATH_MAILDIR) + sizeof(utmp[0].ut_name) + 1]; 174 char buf2[sizeof(_PATH_MAILDIR) + sizeof(utmp[0].ut_name) + 1]; 175 176 if (!(cp = strchr(name, '@'))) 177 return; 178 *cp = '\0'; 179 offset = strtoll(cp + 1, NULL, 10); 180 if (!(cp = strchr(cp + 1, ':'))) 181 file = name; 182 else 183 file = cp + 1; 184 sprintf(buf, "%s/%.*s", _PATH_MAILDIR, (int)sizeof(utmp[0].ut_name), 185 name); 186 if (*file != '/') { 187 sprintf(buf2, "%s/%.*s", _PATH_MAILDIR, 188 (int)sizeof(utmp[0].ut_name), file); 189 file = buf2; 190 } 191 folder = strcmp(buf, file); 192 while (--utp >= utmp) 193 if (!strncmp(utp->ut_name, name, sizeof(utmp[0].ut_name))) 194 notify(utp, file, offset, folder); 195 } 196 197 static char *cr; 198 199 void 200 notify(struct utmp *utp, char file[], off_t offset, int folder) 201 { 202 FILE *tp; 203 struct stat stb; 204 struct termios tio; 205 char tty[20], name[sizeof(utmp[0].ut_name) + 1]; 206 207 (void)snprintf(tty, sizeof(tty), "%s%.*s", 208 _PATH_DEV, (int)sizeof(utp->ut_line), utp->ut_line); 209 if (strchr(tty + sizeof(_PATH_DEV) - 1, '/')) { 210 /* A slash is an attempt to break security... */ 211 syslog(LOG_AUTH | LOG_NOTICE, "'/' in \"%s\"", tty); 212 return; 213 } 214 if (stat(tty, &stb) || !(stb.st_mode & S_IEXEC)) { 215 dsyslog(LOG_DEBUG, "%s: wrong mode on %s", utp->ut_name, tty); 216 return; 217 } 218 dsyslog(LOG_DEBUG, "notify %s on %s\n", utp->ut_name, tty); 219 if (fork()) 220 return; 221 (void)signal(SIGALRM, SIG_DFL); 222 (void)alarm((u_int)30); 223 if ((tp = fopen(tty, "w")) == NULL) { 224 dsyslog(LOG_ERR, "%s: %s", tty, strerror(errno)); 225 _exit(1); 226 } 227 (void)tcgetattr(fileno(tp), &tio); 228 cr = ((tio.c_oflag & (OPOST|ONLCR)) == (OPOST|ONLCR)) ? "\n" : "\n\r"; 229 (void)strncpy(name, utp->ut_name, sizeof(utp->ut_name)); 230 name[sizeof(name) - 1] = '\0'; 231 (void)fprintf(tp, "%s\007New mail for %s@%.*s\007 has arrived%s%s%s:%s----%s", 232 cr, name, (int)sizeof(hostname), hostname, 233 folder ? cr : "", folder ? "to " : "", folder ? file : "", 234 cr, cr); 235 jkfprintf(tp, name, file, offset); 236 (void)fclose(tp); 237 _exit(0); 238 } 239 240 void 241 jkfprintf(FILE *tp, char user[], char file[], off_t offset) 242 { 243 unsigned char *cp, ch; 244 FILE *fi; 245 int linecnt, charcnt, inheader; 246 struct passwd *p; 247 unsigned char line[BUFSIZ]; 248 249 /* Set effective uid to user in case mail drop is on nfs */ 250 if ((p = getpwnam(user)) != NULL) 251 (void) setuid(p->pw_uid); 252 253 if ((fi = fopen(file, "r")) == NULL) 254 return; 255 256 (void)fseeko(fi, offset, SEEK_CUR); 257 /* 258 * Print the first 7 lines or 560 characters of the new mail 259 * (whichever comes first). Skip header crap other than 260 * From, Subject, To, and Date. 261 */ 262 linecnt = 7; 263 charcnt = 560; 264 inheader = 1; 265 while (fgets(line, sizeof(line), fi) != NULL) { 266 if (inheader) { 267 if (line[0] == '\n') { 268 inheader = 0; 269 continue; 270 } 271 if (line[0] == ' ' || line[0] == '\t' || 272 (strncmp(line, "From:", 5) && 273 strncmp(line, "Subject:", 8))) 274 continue; 275 } 276 if (linecnt <= 0 || charcnt <= 0) { 277 (void)fprintf(tp, "...more...%s", cr); 278 (void)fclose(fi); 279 return; 280 } 281 /* strip weird stuff so can't trojan horse stupid terminals */ 282 for (cp = line; (ch = *cp) && ch != '\n'; ++cp, --charcnt) { 283 /* disable upper controls and enable all other 284 8bit codes due to lack of locale knowledge 285 */ 286 if (((ch & 0x80) && ch < 0xA0) || 287 (!(ch & 0x80) && !isprint(ch) && 288 !isspace(ch) && ch != '\a' && ch != '\b') 289 ) { 290 if (ch & 0x80) { 291 ch &= ~0x80; 292 (void)fputs("M-", tp); 293 } 294 if (iscntrl(ch)) { 295 ch ^= 0x40; 296 (void)fputc('^', tp); 297 } 298 } 299 (void)fputc(ch, tp); 300 } 301 (void)fputs(cr, tp); 302 --linecnt; 303 } 304 (void)fprintf(tp, "----%s\n", cr); 305 (void)fclose(fi); 306 } 307