1 # include <stdio.h> 2 # include <pwd.h> 3 # include "dlvrmail.h" 4 5 static char SccsId[] = "@(#)savemail.c 1.4 08/02/80"; 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 29 # define MY_NAME "~MAILER~DAEMON~" 30 31 savemail() 32 { 33 register struct passwd *pw; 34 register FILE *xfile; 35 char buf[MAXLINE+1]; 36 extern errhdr(); 37 auto addrq to_addr; 38 extern struct passwd *getpwnam(); 39 register char *p; 40 register int i; 41 auto long tim; 42 extern int errno; 43 extern char *ttypath(); 44 extern char *ctime(); 45 extern addrq *parse(); 46 static int exclusive; 47 48 if (exclusive++) 49 return; 50 51 /* 52 ** In the unhappy event we don't know who to return the mail 53 ** to, make someone up. 54 */ 55 56 if (From.q_paddr == NULL) 57 { 58 if (parse("root", &From, 0) == NULL) 59 { 60 syserr("Cannot parse root!"); 61 ExitStat = EX_SOFTWARE; 62 finis(); 63 } 64 } 65 66 /* 67 ** If called from Eric Schmidt's network, do special mailback. 68 ** Fundamentally, this is the mailback case except that 69 ** it returns an OK exit status (assuming the return 70 ** worked). 71 */ 72 73 if (BerkNet) 74 { 75 ExitStat = EX_OK; 76 MailBack++; 77 } 78 79 /* 80 ** If writing back, do it. 81 ** If the user is still logged in on the same terminal, 82 ** then write the error messages back to hir (sic). 83 ** If not, set the MailBack flag so that it will get 84 ** mailed back instead. 85 */ 86 87 if (WriteBack) 88 { 89 p = ttypath(); 90 if (p == NULL || freopen(p, "w", stdout) == NULL) 91 { 92 MailBack++; 93 errno = 0; 94 } 95 else 96 { 97 xfile = fopen(Transcript, "r"); 98 if (xfile == NULL) 99 syserr("Cannot open %s", Transcript); 100 printf("\r\nMessage from %s\r\n", MY_NAME); 101 printf("Errors occurred while sending mail, transcript follows:\r\n"); 102 while (fgets(buf, sizeof buf, xfile) && !ferror(stdout)) 103 fputs(buf, stdout); 104 if (ferror(stdout)) 105 syserr("savemail: stdout: write err"); 106 fclose(xfile); 107 } 108 } 109 110 /* 111 ** If mailing back, do it. 112 ** Throw away all further output. Don't do aliases, since 113 ** this could cause loops, e.g., if joe mails to x:joe, 114 ** and for some reason the network for x: is down, then 115 ** the response gets sent to x:joe, which gives a 116 ** response, etc. Also force the mail to be delivered 117 ** even if a version of it has already been sent to the 118 ** sender. 119 */ 120 121 if (MailBack || From.q_mailer != &Mailer[0]) 122 { 123 freopen("/dev/null", "w", stdout); 124 NoAlias++; 125 ForceMail++; 126 127 /* fake up an address header for the from person */ 128 bmove((char *) &From, (char *) &to_addr, sizeof to_addr); 129 if (parse(MY_NAME, &From, -1) == NULL) 130 { 131 syserr("Can't parse myself!"); 132 ExitStat = EX_SOFTWARE; 133 finis(); 134 } 135 i = deliver(&to_addr, errhdr); 136 bmove((char *) &to_addr, (char *) &From, sizeof From); 137 if (i != 0) 138 syserr("Can't return mail to %s", p); 139 else 140 return; 141 } 142 143 /* 144 ** Save the message in dead.letter. 145 ** If we weren't mailing back, and the user is local, we 146 ** should save the message in dead.letter so that the 147 ** poor person doesn't have to type it over again -- 148 ** and we all know what poor typists programmers are. 149 */ 150 151 setuid(getuid()); 152 setgid(getgid()); 153 setpwent(); 154 if (From.q_mailer == &Mailer[0] && (pw = getpwnam(From.q_user)) != NULL) 155 { 156 /* user has a home directory */ 157 p = pw->pw_dir; 158 } 159 else 160 { 161 syserr("Can't return mail to %s (pw=%u)", From.q_paddr, pw); 162 # ifdef DEBUG 163 p = "/usr/tmp"; 164 # else 165 p = NULL; 166 # endif 167 } 168 if (p != NULL) 169 { 170 /* we have a home directory; open dead.letter */ 171 strcpy(buf, p); 172 strcat(buf, "/dead.letter"); 173 xfile = fopen(buf, "a"); 174 if (xfile == NULL) 175 printf("Cannot save mail, sorry\n"); 176 else 177 { 178 rewind(stdin); 179 errno = 0; 180 time(&tim); 181 fprintf(xfile, "----- Mail saved at %s", ctime(&tim)); 182 while (fgets(buf, sizeof buf, stdin) && !ferror(xfile)) 183 fputs(buf, xfile); 184 fputs("\n", xfile); 185 if (ferror(xfile)) 186 syserr("savemail: dead.letter: write err"); 187 fclose(xfile); 188 printf("Letter saved in dead.letter\n"); 189 } 190 } 191 else 192 193 /* add terminator to writeback message */ 194 if (WriteBack) 195 printf("-----\r\n"); 196 } 197 /* 198 ** ERRHDR -- Output the header for error mail. 199 ** 200 ** This is the edit filter to error mailbacks. 201 ** 202 ** Algorithm: 203 ** Output fixed header. 204 ** Output the transcript part. 205 ** Output the original message. 206 ** 207 ** Parameters: 208 ** xfile -- the transcript file. 209 ** fp -- the output file. 210 ** 211 ** Returns: 212 ** none 213 ** 214 ** Side Effects: 215 ** input from xfile 216 ** output to fp 217 ** 218 ** Called By: 219 ** deliver 220 */ 221 222 223 errhdr(fp) 224 register FILE *fp; 225 { 226 char copybuf[512]; 227 register int i; 228 register int xfile; 229 extern int errno; 230 231 if ((xfile = open(Transcript, 0)) < 0) 232 syserr("Cannot open %s", Transcript); 233 fflush(stdout); 234 errno = 0; 235 fprintf(fp, "To: %s\n", To); 236 fprintf(fp, "Subject: Unable to deliver mail\n"); 237 fprintf(fp, "\n ----- Transcript of session follows -----\n"); 238 fflush(fp); 239 while ((i = read(xfile, copybuf, sizeof copybuf)) > 0) 240 write(fileno(fp), copybuf, i); 241 fprintf(fp, "\n ----- Unsent message follows -----\n"); 242 fflush(fp); 243 rewind(stdin); 244 while ((i = read(fileno(stdin), copybuf, sizeof copybuf)) > 0) 245 write(fileno(fp), copybuf, i); 246 close(xfile); 247 if (errno != 0) 248 syserr("errhdr: I/O error"); 249 } 250