1 # include <stdio.h> 2 # include <pwd.h> 3 # include "postbox.h" 4 5 static char SccsId[] = "@(#)savemail.c 3.1 03/07/81"; 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 savemail() 30 { 31 register struct passwd *pw; 32 register FILE *xfile; 33 char buf[MAXLINE+1]; 34 extern errhdr(); 35 auto ADDRESS to_addr; 36 extern struct passwd *getpwnam(); 37 register char *p; 38 register int i; 39 auto long tim; 40 extern int errno; 41 extern char *ttypath(); 42 extern char *ctime(); 43 extern ADDRESS *parse(); 44 static int exclusive; 45 extern char *DaemonName; 46 47 if (exclusive++) 48 return; 49 50 /* 51 ** In the unhappy event we don't know who to return the mail 52 ** to, make someone up. 53 */ 54 55 if (From.q_paddr == NULL) 56 { 57 if (parse("root", &From, 0) == NULL) 58 { 59 syserr("Cannot parse root!"); 60 ExitStat = EX_SOFTWARE; 61 finis(); 62 } 63 } 64 65 /* 66 ** If called from Eric Schmidt's network, do special mailback. 67 ** Fundamentally, this is the mailback case except that 68 ** it returns an OK exit status (assuming the return 69 ** worked). 70 */ 71 72 if (BerkNet) 73 { 74 ExitStat = EX_OK; 75 MailBack++; 76 } 77 78 /* 79 ** If writing back, do it. 80 ** If the user is still logged in on the same terminal, 81 ** then write the error messages back to hir (sic). 82 ** If not, set the MailBack flag so that it will get 83 ** mailed back instead. 84 */ 85 86 if (WriteBack) 87 { 88 p = ttypath(); 89 if (p == NULL || freopen(p, "w", stdout) == NULL) 90 { 91 MailBack++; 92 errno = 0; 93 } 94 else 95 { 96 xfile = fopen(Transcript, "r"); 97 if (xfile == NULL) 98 syserr("Cannot open %s", Transcript); 99 printf("\r\nMessage from %s\r\n", DaemonName); 100 printf("Errors occurred while sending mail, transcript follows:\r\n"); 101 while (fgets(buf, sizeof buf, xfile) && !ferror(stdout)) 102 fputs(buf, stdout); 103 if (ferror(stdout)) 104 syserr("savemail: stdout: write err"); 105 fclose(xfile); 106 } 107 } 108 109 /* 110 ** If mailing back, do it. 111 ** Throw away all further output. Don't do aliases, since 112 ** this could cause loops, e.g., if joe mails to x:joe, 113 ** and for some reason the network for x: is down, then 114 ** the response gets sent to x:joe, which gives a 115 ** response, etc. Also force the mail to be delivered 116 ** even if a version of it has already been sent to the 117 ** sender. 118 */ 119 120 if (MailBack || From.q_mailer != &Mailer[0]) 121 { 122 freopen("/dev/null", "w", stdout); 123 NoAlias++; 124 ForceMail++; 125 126 /* fake up an address header for the from person */ 127 bmove((char *) &From, (char *) &to_addr, sizeof to_addr); 128 if (parse(DaemonName, &From, -1) == NULL) 129 { 130 syserr("Can't parse myself!"); 131 ExitStat = EX_SOFTWARE; 132 finis(); 133 } 134 i = deliver(&to_addr, errhdr); 135 bmove((char *) &to_addr, (char *) &From, sizeof From); 136 if (i != 0) 137 syserr("Can't return mail to %s", p); 138 else 139 return; 140 } 141 142 /* 143 ** Save the message in dead.letter. 144 ** If we weren't mailing back, and the user is local, we 145 ** should save the message in dead.letter so that the 146 ** poor person doesn't have to type it over again -- 147 ** and we all know what poor typists programmers are. 148 */ 149 150 setuid(getuid()); 151 setgid(getgid()); 152 setpwent(); 153 if (From.q_mailer == &Mailer[0] && (pw = getpwnam(From.q_user)) != NULL) 154 { 155 /* user has a home directory */ 156 p = pw->pw_dir; 157 } 158 else 159 { 160 syserr("Can't return mail to %s (pw=%u)", From.q_paddr, pw); 161 # ifdef DEBUG 162 p = "/usr/tmp"; 163 # else 164 p = NULL; 165 # endif 166 } 167 if (p != NULL) 168 { 169 /* we have a home directory; open dead.letter */ 170 strcpy(buf, p); 171 strcat(buf, "/dead.letter"); 172 xfile = fopen(buf, "a"); 173 if (xfile == NULL) 174 printf("Cannot save mail, sorry\n"); 175 else 176 { 177 rewind(stdin); 178 errno = 0; 179 time(&tim); 180 fprintf(xfile, "----- Mail saved at %s", ctime(&tim)); 181 while (fgets(buf, sizeof buf, stdin) && !ferror(xfile)) 182 fputs(buf, xfile); 183 fputs("\n", xfile); 184 if (ferror(xfile)) 185 syserr("savemail: dead.letter: write err"); 186 fclose(xfile); 187 printf("Letter saved in dead.letter\n"); 188 } 189 } 190 else 191 192 /* add terminator to writeback message */ 193 if (WriteBack) 194 printf("-----\r\n"); 195 } 196 /* 197 ** ERRHDR -- Output the header for error mail. 198 ** 199 ** This is the edit filter to error mailbacks. 200 ** 201 ** Algorithm: 202 ** Output fixed header. 203 ** Output the transcript part. 204 ** Output the original message. 205 ** 206 ** Parameters: 207 ** xfile -- the transcript file. 208 ** fp -- the output file. 209 ** 210 ** Returns: 211 ** none 212 ** 213 ** Side Effects: 214 ** input from xfile 215 ** output to fp 216 ** 217 ** Called By: 218 ** deliver 219 */ 220 221 222 errhdr(fp) 223 register FILE *fp; 224 { 225 char copybuf[512]; 226 register int i; 227 register int xfile; 228 extern int errno; 229 230 if ((xfile = open(Transcript, 0)) < 0) 231 syserr("Cannot open %s", Transcript); 232 fflush(stdout); 233 errno = 0; 234 fprintf(fp, "To: %s\n", To); 235 fprintf(fp, "Subject: Unable to deliver mail\n"); 236 fprintf(fp, "\n ----- Transcript of session follows -----\n"); 237 fflush(fp); 238 while ((i = read(xfile, copybuf, sizeof copybuf)) > 0) 239 write(fileno(fp), copybuf, i); 240 fprintf(fp, "\n ----- Unsent message follows -----\n"); 241 fflush(fp); 242 rewind(stdin); 243 while ((i = read(fileno(stdin), copybuf, sizeof copybuf)) > 0) 244 write(fileno(fp), copybuf, i); 245 close(xfile); 246 if (errno != 0) 247 syserr("errhdr: I/O error"); 248 } 249