New SMTP client implementation makes libcurl do all the work.
[citadel.git] / citadel / modules / smtp / smtp_util.c
index 550c2e6afc9fdc8278b177574a3c6a71c1118bb1..4a4ac365bc639a63f2bf0f8abfc95a53d9886051 100644 (file)
@@ -1,24 +1,5 @@
 /*
- * This module is an SMTP and ESMTP implementation for the Citadel system.
- * It is compliant with all of the following:
- *
- * RFC  821 - Simple Mail Transfer Protocol
- * RFC  876 - Survey of SMTP Implementations
- * RFC 1047 - Duplicate messages and SMTP
- * RFC 1652 - 8 bit MIME
- * RFC 1869 - Extended Simple Mail Transfer Protocol
- * RFC 1870 - SMTP Service Extension for Message Size Declaration
- * RFC 2033 - Local Mail Transfer Protocol
- * RFC 2197 - SMTP Service Extension for Command Pipelining
- * RFC 2476 - Message Submission
- * RFC 2487 - SMTP Service Extension for Secure SMTP over TLS
- * RFC 2554 - SMTP Service Extension for Authentication
- * RFC 2821 - Simple Mail Transfer Protocol
- * RFC 2822 - Internet Message Format
- * RFC 2920 - SMTP Service Extension for Command Pipelining
- *  
- * The VRFY and EXPN commands have been removed from this implementation
- * because nobody uses these commands anymore, except for spammers.
+ * Utility functions for the Citadel SMTP implementation
  *
  * Copyright (c) 1998-2017 by the citadel.org team
  *
 #include "clientsocket.h"
 #include "locate_host.h"
 #include "citadel_dirs.h"
-
 #include "ctdl_module.h"
-
 #include "smtp_util.h"
-#include "smtpqueue.h"
-#include "smtp_clienthandlers.h"
 
 const char *smtp_get_Recipients(void)
 {
@@ -95,11 +72,16 @@ const char *smtp_get_Recipients(void)
 
 
 /*
- * smtp_do_bounce() is caled by smtp_do_procmsg() to scan a set of delivery
- * instructions for "5" codes (permanent fatal errors) and produce/deliver
- * a "bounce" message (delivery status notification).
+ * smtp_do_bounce() is caled by smtp_process_one_msg() to scan a set of delivery
+ * instructions for errors and produce/deliver a "bounce" message (delivery
+ * status notification).
+ *
+ * is_final should be set to:
+ *     SDB_BOUNCE_FATALS       Advise the sender of all 5XX (permanent failures)
+ *     SDB_BOUNCE_ALL          Advise the sender that all deliveries have failed and will not be retried
+ *     SDB_WARN                Warn the sender about all 4XX transient delays
  */
-void smtp_do_bounce(char *instr, StrBuf *OMsgTxt)
+void smtp_do_bounce(const char *instr, int is_final)
 {
        int i;
        int lines;
@@ -112,9 +94,7 @@ void smtp_do_bounce(char *instr, StrBuf *OMsgTxt)
        StrBuf *boundary;
        int num_bounces = 0;
        int bounce_this = 0;
-       time_t submitted = 0L;
        struct CtdlMessage *bmsg = NULL;
-       int give_up = 0;
        recptypes *valid;
        int successful_bounce = 0;
        static int seq = 0;
@@ -127,21 +107,6 @@ void smtp_do_bounce(char *instr, StrBuf *OMsgTxt)
 
        StrBufAppendPrintf(boundary, "%s_%04x%04x", CtdlGetConfigStr("c_fqdn"), getpid(), ++seq);
 
-       lines = num_tokens(instr, '\n');
-
-       /* See if it's time to give up on delivery of this message */
-       for (i=0; i<lines; ++i) {
-               extract_token(buf, instr, i, '\n', sizeof buf);
-               extract_token(key, buf, 0, '|', sizeof key);
-               extract_token(addr, buf, 1, '|', sizeof addr);
-               if (!strcasecmp(key, "submitted")) {
-                       submitted = atol(addr);
-               }
-       }
-
-       if ( (time(NULL) - submitted) > SMTP_GIVE_UP ) {
-               give_up = 1;
-       }
 
        /* Start building our bounce message */
 
@@ -162,40 +127,50 @@ void smtp_do_bounce(char *instr, StrBuf *OMsgTxt)
        StrBufAppendBufPlain(BounceMB, HKEY("\"\r\n"), 0);
        StrBufAppendBufPlain(BounceMB, HKEY("MIME-Version: 1.0\r\n"), 0);
        StrBufAppendBufPlain(BounceMB, HKEY("X-Mailer: " CITADEL "\r\n"), 0);
-
-       StrBufAppendBufPlain(
-               BounceMB,
-               HKEY("\r\nThis is a multipart message in MIME format."
-                    "\r\n\r\n"), 0);
-
+       StrBufAppendBufPlain(BounceMB, HKEY("\r\nThis is a multipart message in MIME format.\r\n\r\n"), 0);
        StrBufAppendBufPlain(BounceMB, HKEY("--"), 0);
        StrBufAppendBuf(BounceMB, boundary, 0);
        StrBufAppendBufPlain(BounceMB, HKEY("\r\n"), 0);
-       StrBufAppendBufPlain(BounceMB,
-                            HKEY("Content-type: text/plain\r\n\r\n"), 0);
+       StrBufAppendBufPlain(BounceMB, HKEY("Content-type: text/plain\r\n\r\n"), 0);
 
-       if (give_up)
+       if (is_final == SDB_BOUNCE_ALL)
+       {
+               StrBufAppendBufPlain(
+                       BounceMB,
+                       HKEY(   "A message you sent could not be delivered "
+                               "to some or all of its recipients\ndue to "
+                               "prolonged unavailability of its destination(s).\n"
+                               "Giving up on the following addresses:\n\n"),
+                       0);
+       }
+       else if (is_final == SDB_BOUNCE_FATALS)
        {
                StrBufAppendBufPlain(
                        BounceMB,
-                       HKEY("A message you sent could not be delivered "
-                            "to some or all of its recipients\ndue to "
-                            "prolonged unavailability of its destination(s).\n"
-                            "Giving up on the following addresses:\n\n"), 0);
+                       HKEY(   "A message you sent could not be delivered "
+                               "to some or all of its recipients.\n"
+                               "The following addresses were undeliverable:\n\n"),
+                       0);
        }
-       else
+       else if (is_final == SDB_WARN)
        {
                StrBufAppendBufPlain(
                        BounceMB,
-                       HKEY("A message you sent could not be delivered "
-                            "to some or all of its recipients.\n"
-                            "The following addresses were undeliverable:\n\n"
-                               ), 0);
+                       HKEY("A message you sent has not been delivered "
+                               "to some or all of its recipients.\n"
+                               "Citadel will continue attempting delivery for five days.\n"
+                               "The following addresses were undeliverable:\n\n"),
+                       0);
+       }
+       else    // should never get here
+       {
+               StrBufAppendBufPlain(BounceMB, HKEY("This message should never occur.\n\n"), 0);
        }
 
        /*
         * Now go through the instructions checking for stuff.
         */
+       lines = num_tokens(instr, '\n');
        for (i=0; i<lines; ++i) {
                long addrlen;
                long dsnlen;
@@ -217,21 +192,17 @@ void smtp_do_bounce(char *instr, StrBuf *OMsgTxt)
                }
 
                if (!strcasecmp(key, "remote")) {
-                       if (status == 5) bounce_this = 1;
-                       if (give_up) bounce_this = 1;
+                       if ((is_final == SDB_BOUNCE_FATALS) && (status == 5)) bounce_this = 1;
+                       if ((is_final == SDB_BOUNCE_ALL) && (status != 2)) bounce_this = 1;
+                       if ((is_final == SDB_WARN) && (status == 4)) bounce_this = 1;
                }
 
                if (bounce_this) {
                        ++num_bounces;
-
                        StrBufAppendBufPlain(BounceMB, addr, addrlen, 0);
                        StrBufAppendBufPlain(BounceMB, HKEY(": "), 0);
                        StrBufAppendBufPlain(BounceMB, dsn, dsnlen, 0);
                        StrBufAppendBufPlain(BounceMB, HKEY("\r\n"), 0);
-
-                       remove_token(instr, i, '\n');
-                       --i;
-                       --lines;
                }
        }
 
@@ -240,35 +211,20 @@ void smtp_do_bounce(char *instr, StrBuf *OMsgTxt)
                StrBufAppendBufPlain(BounceMB, HKEY("--"), 0);
                StrBufAppendBuf(BounceMB, boundary, 0);
                StrBufAppendBufPlain(BounceMB, HKEY("\r\n"), 0);
-
-               StrBufAppendBufPlain(
-                       BounceMB,
-                       HKEY("Content-type: message/rfc822\r\n"), 0);
-
-               StrBufAppendBufPlain(
-                       BounceMB,
-                       HKEY("Content-Transfer-Encoding: 7bit\r\n"), 0);
-
-               StrBufAppendBufPlain(
-                       BounceMB,
-                       HKEY("Content-Disposition: inline\r\n"), 0);
-
+               StrBufAppendBufPlain(BounceMB, HKEY("Content-type: message/rfc822\r\n"), 0);
+               StrBufAppendBufPlain(BounceMB, HKEY("Content-Transfer-Encoding: 7bit\r\n"), 0);
+               StrBufAppendBufPlain(BounceMB, HKEY("Content-Disposition: inline\r\n"), 0);
                StrBufAppendBufPlain(BounceMB, HKEY("\r\n"), 0);
 
-               if (OMsgTxt == NULL) {
-                       CC->redirect_buffer = NewStrBufPlain(NULL, SIZ);
-                       CtdlOutputMsg(omsgid,
-                                     MT_RFC822,
-                                     HEADERS_ALL,
-                                     0, 1, NULL, 0,
-                                     NULL, NULL, NULL);
-
-                       StrBufAppendBuf(BounceMB, CC->redirect_buffer, 0);
-                       FreeStrBuf(&CC->redirect_buffer);
-               }
-               else {
-                       StrBufAppendBuf(BounceMB, OMsgTxt, 0);
-               }
+               CC->redirect_buffer = NewStrBufPlain(NULL, SIZ);
+               CtdlOutputMsg(omsgid,
+                       MT_RFC822,
+                       HEADERS_ALL,
+                       0, 1, NULL, 0,
+                       NULL, NULL, NULL
+               );
+               StrBufAppendBuf(BounceMB, CC->redirect_buffer, 0);
+               FreeStrBuf(&CC->redirect_buffer);
        }
 
        /* Close the multipart MIME scope */
@@ -289,9 +245,7 @@ void smtp_do_bounce(char *instr, StrBuf *OMsgTxt)
                        syslog(LOG_DEBUG, "bounce to user <%s>", bounceto);
                }
                /* Can we deliver the bounce to the original sender? */
-               valid = validate_recipients(bounceto,
-                                           smtp_get_Recipients (),
-                                           0);
+               valid = validate_recipients(bounceto, smtp_get_Recipients (), 0);
                if (valid != NULL) {
                        if (valid->num_error == 0) {
                                CtdlSubmitMsg(bmsg, valid, "", QP_EADDR);
@@ -313,3 +267,73 @@ void smtp_do_bounce(char *instr, StrBuf *OMsgTxt)
        CM_Free(bmsg);
        syslog(LOG_DEBUG, "Done processing bounces");
 }
+
+
+
+
+
+char *smtpcodes[][2] = {
+       { "211 - System status / system help reply" },
+       { "214", "Help message" },
+       { "220", "Domain service ready" },
+       { "221", "Domain service closing transmission channel" },
+       { "250", "Requested mail action completed and OK" },
+       { "251", "Not Local User, forward email to forward path" },
+       { "252", "Cannot Verify user, will attempt delivery later" },
+       { "253", "Pending messages for node started" },
+       { "354", "Start mail input; end with ." },
+       { "355", "Octet-offset is the transaction offset" },
+       { "421", "Domain service not available, closing transmission channel" },
+       { "432", "Domain service not available, closing transmission channel" },
+       { "450", "Requested mail action not taken: mailbox unavailable. request refused" },
+       { "451", "Requested action aborted: local error in processing Request is unable to be processed, try again" },
+       { "452", "Requested action not taken: insufficient system storage" },
+       { "453", "No mail" },
+       { "454", "TLS not available due to temporary reason. Encryption required for requested authentication mechanism" },
+       { "458", "Unable to queue messages for node" },
+       { "459", "Node not allowed: reason" },
+       { "500", "Syntax error, command unrecognized" },
+       { "501", "Syntax error in parameters or arguments" },
+       { "502", "Command not implemented" },
+       { "503", "Bad sequence of commands" },
+       { "504", "Command parameter not implemented" },
+       { "510", "Check the recipient address" },
+       { "512", "Domain can not be found. Unknown host." },
+       { "515", "Destination mailbox address invalid" },
+       { "517", "Problem with senders mail attribute, check properties" },
+       { "521", "Domain does not accept mail" },
+       { "522", "Recipient has exceeded mailbox limit" },
+       { "523", "Server limit exceeded. Message too large" },
+       { "530", "Access Denied. Authentication required" },
+       { "531", "Mail system Full" },
+       { "533", "Remote server has insufficient disk space to hold email" },
+       { "534", "Authentication mechanism is too weak. Message too big" },
+       { "535", "Multiple servers using same IP. Required Authentication" },
+       { "538", "Encryption required for requested authentication mechanism" },
+       { "540", "Email address has no DNS Server" },
+       { "541", "No response from host" },
+       { "542", "Bad Connection" },
+       { "543", "Routing server failure. No available route" },
+       { "546", "Email looping" },
+       { "547", "Delivery time-out" },
+       { "550", "Requested action not taken: mailbox unavailable or relaying denied" },
+       { "551", "User not local; please try forward path" },
+       { "552", "Requested mail action aborted: exceeded storage allocation" },
+       { "553", "Requested action not taken: mailbox name not allowed" },
+       { "554", "Transaction failed" }
+};
+
+
+
+char *smtpstatus(int code) {
+       int i;
+
+       for (i=0; i<(sizeof(smtpcodes)/sizeof(char *)/2); ++i) {
+               if (atoi(smtpcodes[i][0]) == code) {
+                       return(smtpcodes[i][1]);
+               }
+       }
+       
+       return("Unknown or other SMTP status");
+}
+