Capture the actual SMTP response from the server, ugly hack using libcurl debug

[citadel.git] / citadel / modules / smtp / serv_smtpclient.c

diff --git a/citadel/modules/smtp/serv_smtpclient.c b/citadel/modules/smtp/serv_smtpclient.c
index dd2c7c9e9b0678f9a1a2b9148d33889e6a0b7def..6354461d3972b287889aa838f83d3dd79f498752 100644 (file)
--- a/citadel/modules/smtp/serv_smtpclient.c
+++ b/citadel/modules/smtp/serv_smtpclient.c
@@ -112,7 +112,8 @@ int smtp_aftersave(struct CtdlMessage *msg, recptypes *recps)
                             "bounceto|%s\n",
                             msg->cm_fields[eVltMsgNum],
                             (long)time(NULL),
-                            recps->bounce_to);
+                            recps->bounce_to
+               );
 
                if (recps->envelope_from != NULL) {
                        StrBufAppendBufPlain(SpoolMsg, HKEY("envelope_from|"), 0);
@@ -164,7 +165,7 @@ static size_t upload_source(void *ptr, size_t size, size_t nmemb, void *userp)
        sendbytes = (size * nmemb);
 
        if (s->bytes_sent >= s->bytes_total) {
-               return(0);                                      // we are donez0r
+               return(0);                                      // no data remaining; we are done
        }
 
        if (sendbytes > (s->bytes_total - s->bytes_sent)) {
@@ -180,11 +181,31 @@ static size_t upload_source(void *ptr, size_t size, size_t nmemb, void *userp)
 }
 
 
+/*
+ * The libcurl API doesn't provide a way to capture the actual SMTP result message returned
+ * by the remote server.  This is an ugly way to extract it, by capturing debug data from
+ * the library and filtering on the lines we want.
+ */
+int ctdl_libcurl_smtp_debug_callback(CURL *handle, curl_infotype type, char *data, size_t size, void *userptr)
+{
+       if (type != CURLINFO_HEADER_IN) return 0;
+       if (!userptr) return 0;
+       char *debugbuf = (char *)userptr;
+
+       int len = strlen(debugbuf);
+       if (len + size > SIZ) return 0;
+
+       memcpy(&debugbuf[len], data, size);
+       debugbuf[len+size] = 0;
+       return 0;
+}
+
+
 /*
  * Attempt a delivery to one recipient.
  * Returns a three-digit SMTP status code.
  */
-int smtp_attempt_delivery(long msgid, char *recp, char *envelope_from)
+int smtp_attempt_delivery(long msgid, char *recp, char *envelope_from, char *response)
 {
        struct smtpmsgsrc s;
        char *fromaddr = NULL;
@@ -223,6 +244,7 @@ int smtp_attempt_delivery(long msgid, char *recp, char *envelope_from)
 
                curl = curl_easy_init();
                if (curl) {
+                       response[0] = 0;
 
                        if (!IsEmptyStr(envelope_from)) {
                                curl_easy_setopt(curl, CURLOPT_MAIL_FROM, envelope_from);
@@ -237,9 +259,15 @@ int smtp_attempt_delivery(long msgid, char *recp, char *envelope_from)
                        curl_easy_setopt(curl, CURLOPT_READDATA, &s);
                        curl_easy_setopt(curl, CURLOPT_UPLOAD, 1);                                              // tell libcurl we are uploading
                        curl_easy_setopt(curl, CURLOPT_TIMEOUT, 20L);                                           // Time out after 20 seconds
+                       if (CtdlGetConfigInt("c_smtpclient_try_starttls") != 0) {
+                               curl_easy_setopt(curl, CURLOPT_USE_SSL, CURLUSESSL_TRY);                        // Attempt STARTTLS if offered
+                       }
                        curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
                        curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);
                        // curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, curl_error_buffer);
+                       curl_easy_setopt(curl, CURLOPT_DEBUGFUNCTION, ctdl_libcurl_smtp_debug_callback);
+                       curl_easy_setopt(curl, CURLOPT_DEBUGDATA, (void *)response);
+                       curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
 
                        // Construct an SMTP URL in the form of:
                        //      smtp[s]://target_host/source_host
@@ -269,6 +297,25 @@ int smtp_attempt_delivery(long msgid, char *recp, char *envelope_from)
                        recipients = NULL;                                                              // this gets reused; avoid double-free
                        curl_easy_cleanup(curl);
                        curl = NULL;                                                                    // this gets reused; avoid double-free
+
+                       /* Trim the error message buffer down to just the actual message */
+                       char response_code_str[4];
+                       snprintf(response_code_str, sizeof response_code_str, "%ld", response_code);
+                       char *respstart = strstr(response, response_code_str);
+                       if (respstart == NULL)
+                       {
+                               strcpy(response, smtpstatus(response_code));
+                       }
+                       else {
+                               strcpy(response, respstart);
+                               char *p;
+                               for (p=response; *p!=0; ++p)
+                               {
+                                       if (*p == '\n') *p = ' ';
+                                       if (*p == '\r') *p = ' ';
+                                       if (!isprint(*p)) *p = ' ';
+                               }
+                       }
                }
        }
 
@@ -291,6 +338,7 @@ void smtp_process_one_msg(long qmsgnum)
        int num_delayed = 0;
        long deletes[2];
        int delete_this_queue = 0;
+       char server_response[SIZ];
 
        msg = CtdlFetchMessage(qmsgnum, 1, 1);
        if (msg == NULL) {
@@ -362,8 +410,8 @@ void smtp_process_one_msg(long qmsgnum)
                                if ((previous_result == 0) || (previous_result == 4)) {
                                        int new_result = 421;
                                        extract_token(recp, cfgline, 1, '|', sizeof recp);
-                                       new_result = smtp_attempt_delivery(msgid, recp, envelope_from);
-                                       syslog(LOG_DEBUG, "smtpclient: recp: <%s> , result: %d (%s)", recp, new_result, smtpstatus(new_result));
+                                       new_result = smtp_attempt_delivery(msgid, recp, envelope_from, server_response);
+                                       syslog(LOG_DEBUG, "smtpclient: recp: <%s> , result: %d (%s)", recp, new_result, server_response);
                                        if ((new_result / 100) == 2) {
                                                ++num_success;
                                        }
@@ -375,7 +423,7 @@ void smtp_process_one_msg(long qmsgnum)
                                                        ++num_delayed;
                                                }
                                                StrBufAppendPrintf(NewInstr, "remote|%s|%ld|%ld (%s)\n",
-                                                       recp, (new_result / 100) , new_result, smtpstatus(new_result)
+                                                       recp, (new_result / 100) , new_result, server_response
                                                );
                                        }
                                }
@@ -402,19 +450,19 @@ void smtp_process_one_msg(long qmsgnum)
                        delete_this_queue = 1;
                }
 
-               // If it's been more than five days, give up and tell the sender we #failed
+               // If it's been more than five days, give up and tell the sender that delivery failed
                //
                else if ((time(NULL) - submitted) > SMTP_DELIVER_FAIL) {
                        smtp_do_bounce(ChrPtr(NewInstr), SDB_BOUNCE_ALL);
                        delete_this_queue = 1;
                }
 
-               // If it's been more than four hours but less than five days, warn the sender that I've Been Delayed
+               // If it's been more than four hours but less than five days, warn the sender that delivery is delayed
                //
                else if ( ((attempted - submitted) < SMTP_DELIVER_WARN) && ((time(NULL) - submitted) >= SMTP_DELIVER_WARN) ) {
                        smtp_do_bounce(ChrPtr(NewInstr), SDB_WARN);
                }
-       
+
                if (delete_this_queue) {
                        syslog(LOG_DEBUG, "smtpclient: %ld deleting", qmsgnum);
                        deletes[0] = qmsgnum;