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 * @(#)comsat.c 8.1 (Berkeley) 6/4/93 34 * $FreeBSD: src/libexec/comsat/comsat.c,v 1.17 2005/02/14 17:42:56 stefanf Exp $ 35 * $DragonFly: src/libexec/comsat/comsat.c,v 1.6 2005/05/03 17:39:03 liamfoy Exp $ 36 */ 37 38 #include <sys/param.h> 39 #include <sys/socket.h> 40 #include <sys/stat.h> 41 #include <sys/file.h> 42 #include <sys/wait.h> 43 44 #include <netinet/in.h> 45 46 #include <ctype.h> 47 #include <err.h> 48 #include <errno.h> 49 #include <netdb.h> 50 #include <paths.h> 51 #include <pwd.h> 52 #include <termios.h> 53 #include <signal.h> 54 #include <stdio.h> 55 #include <stdlib.h> 56 #include <string.h> 57 #include <sysexits.h> 58 #include <syslog.h> 59 #include <unistd.h> 60 #include <utmp.h> 61 62 int debug = 0; 63 #define dsyslog if (debug) syslog 64 65 #define MAXIDLE 120 66 67 char hostname[MAXHOSTNAMELEN]; 68 struct utmp *utmp = NULL; 69 time_t lastmsgtime; 70 int nutmp, uf; 71 72 void jkfprintf (FILE *, const char *, const char *, off_t); 73 void mailfor (char *); 74 void notify (struct utmp *, char *, off_t, int); 75 void onalrm (int); 76 void reapchildren (int); 77 78 int 79 main(int argc __unused, char **argv __unused) 80 { 81 struct sockaddr_in from; 82 socklen_t fromlen; 83 int cc; 84 char msgbuf[256]; 85 86 /* verify proper invocation */ 87 fromlen = sizeof(from); 88 if (getsockname(0, (struct sockaddr *)&from, &fromlen) < 0) 89 err(1, "getsockname"); 90 openlog("comsat", LOG_PID, LOG_DAEMON); 91 if (chdir(_PATH_MAILDIR)) { 92 syslog(LOG_ERR, "chdir: %s: %m", _PATH_MAILDIR); 93 recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 94 exit(1); 95 } 96 if ((uf = open(_PATH_UTMP, O_RDONLY, 0)) < 0) { 97 syslog(LOG_ERR, "open: %s: %m", _PATH_UTMP); 98 recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 99 exit(1); 100 } 101 time(&lastmsgtime); 102 gethostname(hostname, sizeof(hostname)); 103 onalrm(0); 104 signal(SIGALRM, onalrm); 105 signal(SIGTTOU, SIG_IGN); 106 signal(SIGCHLD, reapchildren); 107 for (;;) { 108 cc = recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 109 if (cc <= 0) { 110 if (errno != EINTR) 111 sleep(1); 112 errno = 0; 113 continue; 114 } 115 if (!nutmp) /* no one has logged in yet */ 116 continue; 117 sigblock(sigmask(SIGALRM)); 118 msgbuf[cc] = '\0'; 119 time(&lastmsgtime); 120 mailfor(msgbuf); 121 sigsetmask(0L); 122 } 123 } 124 125 void 126 reapchildren(int signo __unused) 127 { 128 while (wait3(NULL, WNOHANG, NULL) > 0); 129 } 130 131 void 132 onalrm(int signo __unused) 133 { 134 static u_int utmpsize; /* last malloced size for utmp */ 135 static time_t utmpmtime; /* last modification time for utmp */ 136 struct stat statbf; 137 138 if (time(NULL) - lastmsgtime >= MAXIDLE) 139 exit(EX_OK); 140 alarm((u_int)15); 141 fstat(uf, &statbf); 142 if (statbf.st_mtime > utmpmtime) { 143 utmpmtime = statbf.st_mtime; 144 if (statbf.st_size > utmpsize) { 145 utmpsize = statbf.st_size + 10 * sizeof(struct utmp); 146 if ((utmp = realloc(utmp, utmpsize)) == NULL) { 147 syslog(LOG_ERR, "realloc: %m"); 148 exit(1); 149 } 150 } 151 lseek(uf, (off_t)0, SEEK_SET); 152 nutmp = read(uf, utmp, (size_t)statbf.st_size)/sizeof(struct utmp); 153 } 154 } 155 156 void 157 mailfor(char *name) 158 { 159 struct utmp *utp = &utmp[nutmp]; 160 char *cp; 161 char *file; 162 off_t offset; 163 int folder; 164 char buf[sizeof(_PATH_MAILDIR) + sizeof(utmp[0].ut_name) + 1]; 165 char buf2[sizeof(_PATH_MAILDIR) + sizeof(utmp[0].ut_name) + 1]; 166 167 if (!(cp = strchr(name, '@'))) 168 return; 169 *cp = '\0'; 170 offset = strtoll(cp + 1, NULL, 10); 171 if (!(cp = strchr(cp + 1, ':'))) 172 file = name; 173 else 174 file = cp + 1; 175 sprintf(buf, "%s/%.*s", _PATH_MAILDIR, (int)sizeof(utmp[0].ut_name), 176 name); 177 if (*file != '/') { 178 sprintf(buf2, "%s/%.*s", _PATH_MAILDIR, 179 (int)sizeof(utmp[0].ut_name), file); 180 file = buf2; 181 } 182 folder = strcmp(buf, file); 183 while (--utp >= utmp) 184 if (!strncmp(utp->ut_name, name, sizeof(utmp[0].ut_name))) 185 notify(utp, file, offset, folder); 186 } 187 188 static const char *cr; 189 190 void 191 notify(struct utmp *utp, char *file, off_t offset, int folder) 192 { 193 FILE *tp; 194 struct stat stb; 195 struct termios tio; 196 char tty[20], name[sizeof(utmp[0].ut_name) + 1]; 197 198 snprintf(tty, sizeof(tty), "%s%.*s", 199 _PATH_DEV, (int)sizeof(utp->ut_line), utp->ut_line); 200 if (strchr(tty + sizeof(_PATH_DEV) - 1, '/')) { 201 /* A slash is an attempt to break security... */ 202 syslog(LOG_AUTH | LOG_NOTICE, "'/' in \"%s\"", tty); 203 return; 204 } 205 if (stat(tty, &stb) || !(stb.st_mode & (S_IXUSR | S_IXGRP))) { 206 dsyslog(LOG_DEBUG, "%s: wrong mode on %s", utp->ut_name, tty); 207 return; 208 } 209 dsyslog(LOG_DEBUG, "notify %s on %s\n", utp->ut_name, tty); 210 if (fork()) 211 return; 212 signal(SIGALRM, SIG_DFL); 213 alarm((u_int)30); 214 if ((tp = fopen(tty, "w")) == NULL) { 215 dsyslog(LOG_ERR, "%s: %s", tty, strerror(errno)); 216 _exit(1); 217 } 218 tcgetattr(fileno(tp), &tio); 219 cr = ((tio.c_oflag & (OPOST|ONLCR)) == (OPOST|ONLCR)) ? "\n" : "\n\r"; 220 strncpy(name, utp->ut_name, sizeof(utp->ut_name)); 221 name[sizeof(name) - 1] = '\0'; 222 switch (stb.st_mode & (S_IXUSR | S_IXGRP)) { 223 case S_IXUSR: 224 case (S_IXUSR | S_IXGRP): 225 fprintf(tp, 226 "%s\007New mail for %s@%.*s\007 has arrived%s%s%s:%s----%s", 227 cr, name, (int)sizeof(hostname), hostname, 228 folder ? cr : "", folder ? "to " : "", folder ? file : "", 229 cr, cr); 230 jkfprintf(tp, name, file, offset); 231 break; 232 case S_IXGRP: 233 fprintf(tp, "\007"); 234 fflush(tp); 235 sleep(1); 236 fprintf(tp, "\007"); 237 break; 238 default: 239 break; 240 } 241 fclose(tp); 242 _exit(EX_OK); 243 } 244 245 void 246 jkfprintf(FILE *tp, const char *user, const char *file, off_t offset) 247 { 248 unsigned char *cp, ch; 249 FILE *fi; 250 int linecnt, charcnt, inheader; 251 struct passwd *p; 252 unsigned char line[BUFSIZ]; 253 254 /* Set effective uid to user in case mail drop is on nfs */ 255 if ((p = getpwnam(user)) != NULL) 256 setuid(p->pw_uid); 257 258 if ((fi = fopen(file, "r")) == NULL) 259 return; 260 261 fseeko(fi, offset, SEEK_SET); 262 /* 263 * Print the first 7 lines or 560 characters of the new mail 264 * (whichever comes first). Skip header crap other than 265 * From, Subject, To, and Date. 266 */ 267 linecnt = 7; 268 charcnt = 560; 269 inheader = 1; 270 while (fgets(line, sizeof(line), fi) != NULL) { 271 if (inheader) { 272 if (line[0] == '\n') { 273 inheader = 0; 274 continue; 275 } 276 if (line[0] == ' ' || line[0] == '\t' || 277 (strncmp(line, "From:", 5) && 278 strncmp(line, "Subject:", 8))) 279 continue; 280 } 281 if (linecnt <= 0 || charcnt <= 0) { 282 fprintf(tp, "...more...%s", cr); 283 fclose(fi); 284 return; 285 } 286 /* strip weird stuff so can't trojan horse stupid terminals */ 287 for (cp = line; (ch = *cp) && ch != '\n'; ++cp, --charcnt) { 288 /* disable upper controls and enable all other 289 8bit codes due to lack of locale knowledge 290 */ 291 if (((ch & 0x80) && ch < 0xA0) || 292 (!(ch & 0x80) && !isprint(ch) && 293 !isspace(ch) && ch != '\a' && ch != '\b') 294 ) { 295 if (ch & 0x80) { 296 ch &= ~0x80; 297 fputs("M-", tp); 298 } 299 if (iscntrl(ch)) { 300 ch ^= 0x40; 301 fputc('^', tp); 302 } 303 } 304 fputc(ch, tp); 305 } 306 fputs(cr, tp); 307 --linecnt; 308 } 309 fprintf(tp, "----%s\n", cr); 310 fclose(fi); 311 } 312