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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)comsat.c 8.1 (Berkeley) 6/4/93 30 * $FreeBSD: src/libexec/comsat/comsat.c,v 1.17 2005/02/14 17:42:56 stefanf Exp $ 31 */ 32 33 #include <sys/param.h> 34 #include <sys/socket.h> 35 #include <sys/stat.h> 36 #include <sys/file.h> 37 #include <sys/wait.h> 38 39 #include <netinet/in.h> 40 41 #include <ctype.h> 42 #include <err.h> 43 #include <errno.h> 44 #include <netdb.h> 45 #include <paths.h> 46 #include <pwd.h> 47 #include <termios.h> 48 #include <signal.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #include <sysexits.h> 53 #include <syslog.h> 54 #include <unistd.h> 55 #include <utmp.h> 56 57 int debug = 0; 58 #define dsyslog if (debug) syslog 59 60 #define MAXIDLE 120 61 62 char hostname[MAXHOSTNAMELEN]; 63 struct utmp *utmp = NULL; 64 time_t lastmsgtime; 65 int nutmp, uf; 66 67 void jkfprintf (FILE *, const char *, const char *, off_t); 68 void mailfor (char *); 69 void notify (struct utmp *, char *, off_t, int); 70 void onalrm (int); 71 void reapchildren (int); 72 73 int 74 main(int argc __unused, char **argv __unused) 75 { 76 struct sockaddr_in from; 77 socklen_t fromlen; 78 int cc; 79 char msgbuf[256]; 80 81 /* verify proper invocation */ 82 fromlen = sizeof(from); 83 if (getsockname(0, (struct sockaddr *)&from, &fromlen) < 0) 84 err(1, "getsockname"); 85 openlog("comsat", LOG_PID, LOG_DAEMON); 86 if (chdir(_PATH_MAILDIR)) { 87 syslog(LOG_ERR, "chdir: %s: %m", _PATH_MAILDIR); 88 recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 89 exit(1); 90 } 91 if ((uf = open(_PATH_UTMP, O_RDONLY, 0)) < 0) { 92 syslog(LOG_ERR, "open: %s: %m", _PATH_UTMP); 93 recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 94 exit(1); 95 } 96 time(&lastmsgtime); 97 gethostname(hostname, sizeof(hostname)); 98 onalrm(0); 99 signal(SIGALRM, onalrm); 100 signal(SIGTTOU, SIG_IGN); 101 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 if (!nutmp) /* no one has logged in yet */ 111 continue; 112 sigblock(sigmask(SIGALRM)); 113 msgbuf[cc] = '\0'; 114 time(&lastmsgtime); 115 mailfor(msgbuf); 116 sigsetmask(0L); 117 } 118 } 119 120 void 121 reapchildren(int signo __unused) 122 { 123 while (wait3(NULL, WNOHANG, NULL) > 0); 124 } 125 126 void 127 onalrm(int signo __unused) 128 { 129 static u_int utmpsize; /* last malloced size for utmp */ 130 static time_t utmpmtime; /* last modification time for utmp */ 131 struct stat statbf; 132 133 if (time(NULL) - lastmsgtime >= MAXIDLE) 134 exit(EX_OK); 135 alarm((u_int)15); 136 fstat(uf, &statbf); 137 if (statbf.st_mtime > utmpmtime) { 138 utmpmtime = statbf.st_mtime; 139 if (statbf.st_size > utmpsize) { 140 utmpsize = statbf.st_size + 10 * sizeof(struct utmp); 141 if ((utmp = realloc(utmp, utmpsize)) == NULL) { 142 syslog(LOG_ERR, "realloc: %m"); 143 exit(1); 144 } 145 } 146 lseek(uf, (off_t)0, SEEK_SET); 147 nutmp = read(uf, utmp, (size_t)statbf.st_size)/sizeof(struct utmp); 148 } 149 } 150 151 void 152 mailfor(char *name) 153 { 154 struct utmp *utp = &utmp[nutmp]; 155 char *cp; 156 char *file; 157 off_t offset; 158 int folder; 159 char buf[sizeof(_PATH_MAILDIR) + sizeof(utmp[0].ut_name) + 1]; 160 char buf2[sizeof(_PATH_MAILDIR) + sizeof(utmp[0].ut_name) + 1]; 161 162 if (!(cp = strchr(name, '@'))) 163 return; 164 *cp = '\0'; 165 offset = strtoll(cp + 1, NULL, 10); 166 if (!(cp = strchr(cp + 1, ':'))) 167 file = name; 168 else 169 file = cp + 1; 170 sprintf(buf, "%s/%.*s", _PATH_MAILDIR, (int)sizeof(utmp[0].ut_name), 171 name); 172 if (*file != '/') { 173 sprintf(buf2, "%s/%.*s", _PATH_MAILDIR, 174 (int)sizeof(utmp[0].ut_name), file); 175 file = buf2; 176 } 177 folder = strcmp(buf, file); 178 while (--utp >= utmp) 179 if (!strncmp(utp->ut_name, name, sizeof(utmp[0].ut_name))) 180 notify(utp, file, offset, folder); 181 } 182 183 static const char *cr; 184 185 void 186 notify(struct utmp *utp, char *file, off_t offset, int folder) 187 { 188 FILE *tp; 189 struct stat stb; 190 struct termios tio; 191 char tty[20], name[sizeof(utmp[0].ut_name) + 1]; 192 193 snprintf(tty, sizeof(tty), "%s%.*s", 194 _PATH_DEV, (int)sizeof(utp->ut_line), utp->ut_line); 195 if (strchr(tty + sizeof(_PATH_DEV) - 1, '/')) { 196 /* A slash is an attempt to break security... */ 197 syslog(LOG_AUTH | LOG_NOTICE, "'/' in \"%s\"", tty); 198 return; 199 } 200 if (stat(tty, &stb) || !(stb.st_mode & (S_IXUSR | S_IXGRP))) { 201 dsyslog(LOG_DEBUG, "%s: wrong mode on %s", utp->ut_name, tty); 202 return; 203 } 204 dsyslog(LOG_DEBUG, "notify %s on %s\n", utp->ut_name, tty); 205 if (fork()) 206 return; 207 signal(SIGALRM, SIG_DFL); 208 alarm((u_int)30); 209 if ((tp = fopen(tty, "w")) == NULL) { 210 dsyslog(LOG_ERR, "%s: %s", tty, strerror(errno)); 211 _exit(1); 212 } 213 tcgetattr(fileno(tp), &tio); 214 cr = ((tio.c_oflag & (OPOST|ONLCR)) == (OPOST|ONLCR)) ? "\n" : "\n\r"; 215 strncpy(name, utp->ut_name, sizeof(name)); 216 switch (stb.st_mode & (S_IXUSR | S_IXGRP)) { 217 case S_IXUSR: 218 case (S_IXUSR | S_IXGRP): 219 fprintf(tp, 220 "%s\007New mail for %s@%.*s\007 has arrived%s%s%s:%s----%s", 221 cr, name, (int)sizeof(hostname), hostname, 222 folder ? cr : "", folder ? "to " : "", folder ? file : "", 223 cr, cr); 224 jkfprintf(tp, name, file, offset); 225 break; 226 case S_IXGRP: 227 fprintf(tp, "\007"); 228 fflush(tp); 229 sleep(1); 230 fprintf(tp, "\007"); 231 break; 232 default: 233 break; 234 } 235 fclose(tp); 236 _exit(EX_OK); 237 } 238 239 void 240 jkfprintf(FILE *tp, const char *user, const char *file, off_t offset) 241 { 242 unsigned char *cp, ch; 243 FILE *fi; 244 int linecnt, charcnt, inheader; 245 struct passwd *p; 246 unsigned char line[BUFSIZ]; 247 248 /* Set effective uid to user in case mail drop is on nfs */ 249 if ((p = getpwnam(user)) != NULL) 250 setuid(p->pw_uid); 251 252 if ((fi = fopen(file, "r")) == NULL) 253 return; 254 255 fseeko(fi, offset, SEEK_SET); 256 /* 257 * Print the first 7 lines or 560 characters of the new mail 258 * (whichever comes first). Skip header crap other than 259 * From, Subject, To, and Date. 260 */ 261 linecnt = 7; 262 charcnt = 560; 263 inheader = 1; 264 while (fgets(line, sizeof(line), fi) != NULL) { 265 if (inheader) { 266 if (line[0] == '\n') { 267 inheader = 0; 268 continue; 269 } 270 if (line[0] == ' ' || line[0] == '\t' || 271 (strncmp(line, "From:", 5) && 272 strncmp(line, "Subject:", 8))) 273 continue; 274 } 275 if (linecnt <= 0 || charcnt <= 0) { 276 fprintf(tp, "...more...%s", cr); 277 fclose(fi); 278 return; 279 } 280 /* strip weird stuff so can't trojan horse stupid terminals */ 281 for (cp = line; (ch = *cp) && ch != '\n'; ++cp, --charcnt) { 282 /* disable upper controls and enable all other 283 8bit codes due to lack of locale knowledge 284 */ 285 if (((ch & 0x80) && ch < 0xA0) || 286 (!(ch & 0x80) && !isprint(ch) && 287 !isspace(ch) && ch != '\a' && ch != '\b') 288 ) { 289 if (ch & 0x80) { 290 ch &= ~0x80; 291 fputs("M-", tp); 292 } 293 if (iscntrl(ch)) { 294 ch ^= 0x40; 295 fputc('^', tp); 296 } 297 } 298 fputc(ch, tp); 299 } 300 fputs(cr, tp); 301 --linecnt; 302 } 303 fprintf(tp, "----%s\n", cr); 304 fclose(fi); 305 } 306