1 # include <stdio.h> 2 # include <pwd.h> 3 # include "dlvrmail.h" 4 5 static char SccsId[] = "@(#)savemail.c 1.3 07/25/80"; 6 7 /* 8 ** SAVEMAIL -- Save mail on error 9 ** 10 ** If the MailBack flag is set, mail it back to the originator 11 ** together with an error message; otherwise, just put it in 12 ** dead.letter in the user's home directory (if he exists on 13 ** this machine). 14 ** 15 ** Parameters: 16 ** none 17 ** 18 ** Returns: 19 ** none 20 ** 21 ** Side Effects: 22 ** Saves the letter, by writing or mailing it back to the 23 ** sender, or by putting it in dead.letter in her home 24 ** directory. 25 ** 26 ** WARNING: the user id is reset to the original user. 27 ** 28 ** Requires: 29 ** fopen (sys) 30 ** bmove 31 ** parse 32 ** deliver 33 ** strcpy (sys) 34 ** strcat (sys) 35 ** fclose (sys) 36 ** fgets (sys) 37 ** fputs (sys) 38 ** setpwent (sys) 39 ** getuid (sys) 40 ** setuid (sys) 41 ** getgid (sys) 42 ** setgid (sys) 43 ** getpwnam (sys) 44 ** fprintf (sys) 45 ** ttypath 46 ** freopen (sys) 47 ** printf (sys) 48 ** syserr 49 ** rewind (sys) 50 ** time (sys) 51 ** ferror (sys) 52 ** 53 ** Called By: 54 ** finis 55 ** 56 ** History: 57 ** 12/30/79 -- written. 58 */ 59 60 # define MY_NAME "~MAILER~DAEMON~" 61 62 savemail() 63 { 64 register struct passwd *pw; 65 register FILE *xfile; 66 char buf[MAXLINE+1]; 67 extern errhdr(); 68 auto addrq to_addr; 69 extern struct passwd *getpwnam(); 70 register char *p; 71 register int i; 72 auto long tim; 73 extern int errno; 74 extern char *ttypath(); 75 extern char *ctime(); 76 extern addrq *parse(); 77 static int exclusive; 78 79 if (exclusive++) 80 return; 81 82 /* 83 ** In the unhappy event we don't know who to return the mail 84 ** to, make someone up. 85 */ 86 87 if (From.q_paddr == NULL) 88 { 89 if (parse("root", &From, 0) == NULL) 90 { 91 syserr("Cannot parse root!"); 92 ExitStat = EX_SOFTWARE; 93 finis(); 94 } 95 } 96 97 /* 98 ** If called from Eric Schmidt's network, do special mailback. 99 ** Fundamentally, this is the mailback case except that 100 ** it returns an OK exit status (assuming the return 101 ** worked). 102 */ 103 104 if (BerkNet) 105 { 106 ExitStat = EX_OK; 107 MailBack++; 108 } 109 110 /* 111 ** If writing back, do it. 112 ** If the user is still logged in on the same terminal, 113 ** then write the error messages back to hir (sic). 114 ** If not, set the MailBack flag so that it will get 115 ** mailed back instead. 116 */ 117 118 if (WriteBack) 119 { 120 p = ttypath(); 121 if (p == NULL || freopen(p, "w", stdout) == NULL) 122 { 123 MailBack++; 124 errno = 0; 125 } 126 else 127 { 128 xfile = fopen(Transcript, "r"); 129 if (xfile == NULL) 130 syserr("Cannot open %s", Transcript); 131 printf("\r\nMessage from %s\r\n", MY_NAME); 132 printf("Errors occurred while sending mail, transcript follows:\r\n"); 133 while (fgets(buf, sizeof buf, xfile) && !ferror(stdout)) 134 fputs(buf, stdout); 135 if (ferror(stdout)) 136 syserr("savemail: stdout: write err"); 137 fclose(xfile); 138 } 139 } 140 141 /* 142 ** If mailing back, do it. 143 ** Throw away all further output. Don't do aliases, since 144 ** this could cause loops, e.g., if joe mails to x:joe, 145 ** and for some reason the network for x: is down, then 146 ** the response gets sent to x:joe, which gives a 147 ** response, etc. Also force the mail to be delivered 148 ** even if a version of it has already been sent to the 149 ** sender. 150 */ 151 152 if (MailBack || From.q_mailer != &Mailer[0]) 153 { 154 freopen("/dev/null", "w", stdout); 155 NoAlias++; 156 ForceMail++; 157 158 /* fake up an address header for the from person */ 159 bmove((char *) &From, (char *) &to_addr, sizeof to_addr); 160 if (parse(MY_NAME, &From, -1) == NULL) 161 { 162 syserr("Can't parse myself!"); 163 ExitStat = EX_SOFTWARE; 164 finis(); 165 } 166 i = deliver(&to_addr, errhdr); 167 bmove((char *) &to_addr, (char *) &From, sizeof From); 168 if (i != 0) 169 syserr("Can't return mail to %s", p); 170 else 171 return; 172 } 173 174 /* 175 ** Save the message in dead.letter. 176 ** If we weren't mailing back, and the user is local, we 177 ** should save the message in dead.letter so that the 178 ** poor person doesn't have to type it over again -- 179 ** and we all know what poor typists programmers are. 180 */ 181 182 setuid(getuid()); 183 setgid(getgid()); 184 setpwent(); 185 if (From.q_mailer == &Mailer[0] && (pw = getpwnam(From.q_user)) != NULL) 186 { 187 /* user has a home directory */ 188 p = pw->pw_dir; 189 } 190 else 191 { 192 syserr("Can't return mail to %s (pw=%u)", From.q_paddr, pw); 193 # ifdef DEBUG 194 p = "/usr/tmp"; 195 # else 196 p = NULL; 197 # endif 198 } 199 if (p != NULL) 200 { 201 /* we have a home directory; open dead.letter */ 202 strcpy(buf, p); 203 strcat(buf, "/dead.letter"); 204 xfile = fopen(buf, "a"); 205 if (xfile == NULL) 206 printf("Cannot save mail, sorry\n"); 207 else 208 { 209 rewind(stdin); 210 errno = 0; 211 time(&tim); 212 fprintf(xfile, "----- Mail saved at %s", ctime(&tim)); 213 while (fgets(buf, sizeof buf, stdin) && !ferror(xfile)) 214 fputs(buf, xfile); 215 fputs("\n", xfile); 216 if (ferror(xfile)) 217 syserr("savemail: dead.letter: write err"); 218 fclose(xfile); 219 printf("Letter saved in dead.letter\n"); 220 } 221 } 222 else 223 224 /* add terminator to writeback message */ 225 if (WriteBack) 226 printf("-----\r\n"); 227 } 228 /* 229 ** ERRHDR -- Output the header for error mail. 230 ** 231 ** This is the edit filter to error mailbacks. 232 ** 233 ** Algorithm: 234 ** Output fixed header. 235 ** Output the transcript part. 236 ** Output the original message. 237 ** 238 ** Parameters: 239 ** xfile -- the transcript file. 240 ** fp -- the output file. 241 ** 242 ** Returns: 243 ** none 244 ** 245 ** Side Effects: 246 ** input from xfile 247 ** output to fp 248 ** 249 ** Requires: 250 ** read (sys) 251 ** write (sys) 252 ** open (sys) 253 ** close (sys) 254 ** syserr 255 ** rewind (sys) 256 ** fflush (sys) 257 ** fprintf (sys) 258 ** fileno (sys) 259 ** 260 ** Called By: 261 ** deliver 262 ** 263 ** History: 264 ** 12/28/79 -- written. 265 */ 266 267 268 errhdr(fp) 269 register FILE *fp; 270 { 271 char copybuf[512]; 272 register int i; 273 register int xfile; 274 extern int errno; 275 276 if ((xfile = open(Transcript, 0)) < 0) 277 syserr("Cannot open %s", Transcript); 278 fflush(stdout); 279 errno = 0; 280 fprintf(fp, "To: %s\n", To); 281 fprintf(fp, "Subject: Unable to deliver mail\n"); 282 fprintf(fp, "\n ----- Transcript of session follows -----\n"); 283 fflush(fp); 284 while ((i = read(xfile, copybuf, sizeof copybuf)) > 0) 285 write(fileno(fp), copybuf, i); 286 fprintf(fp, "\n ----- Unsent message follows -----\n"); 287 fflush(fp); 288 rewind(stdin); 289 while ((i = read(fileno(stdin), copybuf, sizeof copybuf)) > 0) 290 write(fileno(fp), copybuf, i); 291 close(xfile); 292 if (errno != 0) 293 syserr("errhdr: I/O error"); 294 } 295