curl smtp

/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2011, Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at http://curl.haxx.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ***************************************************************************/

#include <stddef.h>
#include <stdlib.h>
#include <curl/curl.h>

struct pair
{
    const char* content;
    size_t size;
    size_t written_bytes;
};

struct data
{
  char trace_ascii;
};

size_t smtp_read_callback(void *ptr,
    size_t size,
    size_t nmemb,
    void *data);

void dump(const char *text,
          FILE *stream, unsigned char *ptr, size_t size,
          char nohex);

int my_trace(CURL *handle, curl_infotype type,
             char *data, size_t size,
             void *userp);

int main(void)
{
    const char* cacert_filepath = "";
    int smtp_port = 25;
    const char* smtp_host = "";
    const char* smtp_login = "";
    const char* smtp_password = "";
    const char* sender_email = "";
    const char* recipient = "";

    char *buffer = (char *)malloc((CURL_MAX_WRITE_SIZE + 3) * sizeof(char));
    int line_length = 0;
    int pos = 0;
    while(pos != CURL_MAX_WRITE_SIZE)
    {
        if(line_length == 64)
        {
            buffer[pos] = '\r';
            buffer[++pos] = '\n';
            line_length = 0;
        }
        else
        {
            buffer[pos] = 'A';
            ++line_length;
        }
        ++pos;
    }
    buffer[CURL_MAX_WRITE_SIZE - 1] = '\r';
    buffer[CURL_MAX_WRITE_SIZE] = '\n';
    buffer[CURL_MAX_WRITE_SIZE + 1] = 'B';
    buffer[CURL_MAX_WRITE_SIZE + 2] = '\0';

    pair body;
    body.content = buffer;
    body.size = CURL_MAX_WRITE_SIZE + 2;
    body.written_bytes = 0;

    data config;
    config.trace_ascii = 1;

    curl_global_init(CURL_GLOBAL_ALL );
    CURL* curl_ptr = curl_easy_init();
    if(!curl_ptr)
        return 1;


    curl_easy_setopt(curl_ptr, CURLOPT_DEBUGFUNCTION, my_trace);
    curl_easy_setopt(curl_ptr, CURLOPT_DEBUGDATA, &config);
    curl_easy_setopt(curl_ptr, CURLOPT_VERBOSE, 1L);

    curl_easy_setopt(curl_ptr,CURLOPT_TIMEOUT,120);

    curl_easy_setopt(curl_ptr, CURLOPT_USE_SSL, CURLUSESSL_ALL);
    curl_easy_setopt(curl_ptr, CURLOPT_SSL_VERIFYPEER,1);
    curl_easy_setopt(curl_ptr, CURLOPT_SSL_VERIFYHOST, 2);
    curl_easy_setopt(curl_ptr, CURLOPT_CAINFO, cacert_filepath);
    curl_easy_setopt(curl_ptr, CURLOPT_SSLVERSION, CURL_SSLVERSION_DEFAULT);
    curl_easy_setopt(curl_ptr, CURLOPT_SSL_SESSIONID_CACHE, 1);

    curl_easy_setopt(curl_ptr, CURLOPT_URL, smtp_host);
    curl_easy_setopt(curl_ptr, CURLOPT_PORT, smtp_port);
    curl_easy_setopt(curl_ptr, CURLOPT_USERNAME, smtp_login);
    curl_easy_setopt(curl_ptr, CURLOPT_PASSWORD, smtp_password);
    curl_easy_setopt(curl_ptr, CURLOPT_MAIL_FROM, sender_email);

    struct curl_slist* rcpt_list = NULL;
    rcpt_list = curl_slist_append(rcpt_list, recipient);
    curl_easy_setopt(curl_ptr, CURLOPT_MAIL_RCPT, rcpt_list);

    curl_easy_setopt(curl_ptr, CURLOPT_READFUNCTION, smtp_read_callback);
    curl_easy_setopt(curl_ptr, CURLOPT_READDATA, &body);

    CURLcode error_code = curl_easy_perform(curl_ptr);
    if(error_code != CURLE_OK)
        return 1;

    curl_slist_free_all(rcpt_list);
    curl_easy_cleanup(curl_ptr);
    curl_global_cleanup();
    free(buffer);
    return 0;
}

size_t smtp_read_callback(void *ptr,
    size_t size,
    size_t nmemb,
    void *data)
{
    pair *body = (pair*)data;

    if (data)
    {
        int available = (body->size - body->written_bytes);
        if (available > 0)
        {
            int written = min(size * nmemb,available);
            memcpy((char *)ptr,
                body->content + body->written_bytes,
                written);
            body->written_bytes += written;
            return written;
        }
    }
    else
        return CURL_READFUNC_ABORT;
    return 0;
}



void dump(const char *text,
          FILE *stream, unsigned char *ptr, size_t size,
          char nohex)
{
  size_t i;
  size_t c;

  unsigned int width=0x10;

  if(nohex)
    /* without the hex output, we can fit more on screen */
    width = 0x40;

  fprintf(stream, "%s, %10.10ld bytes (0x%8.8lx)\n",
          text, (long)size, (long)size);

  for(i=0; i<size; i+= width) {

    fprintf(stream, "%4.4lx: ", (long)i);

    if(!nohex) {
      /* hex not disabled, show it */
      for(c = 0; c < width; c++)
        if(i+c < size)
          fprintf(stream, "%02x ", ptr[i+c]);
        else
          fputs("   ", stream);
    }

    for(c = 0; (c < width) && (i+c < size); c++) {
      /* check for 0D0A; if found, skip past and start a new line of output */
      if (nohex && (i+c+1 < size) && ptr[i+c]==0x0D && ptr[i+c+1]==0x0A) {
        i+=(c+2-width);
        break;
      }
      fprintf(stream, "%c",
              (ptr[i+c]>=0x20) && (ptr[i+c]<0x80)?ptr[i+c]:'.');
      /* check again for 0D0A, to avoid an extra \n if it's at width */
      if (nohex && (i+c+2 < size) && ptr[i+c+1]==0x0D && ptr[i+c+2]==0x0A) {
        i+=(c+3-width);
        break;
      }
    }
    fputc('\n', stream); /* newline */
  }
  fflush(stream);
}

int my_trace(CURL *handle, curl_infotype type,
             char *data, size_t size,
             void *userp)
{
  struct data *config = (struct data *)userp;
  const char *text;
  (void)handle; /* prevent compiler warning */

  switch (type) {
  case CURLINFO_TEXT:
    fprintf(stderr, "== Info: %s", data);
  default: /* in case a new one is introduced to shock us */
    return 0;

  case CURLINFO_HEADER_OUT:
    text = "=> Send header";
    break;
  case CURLINFO_DATA_OUT:
    text = "=> Send data";
    break;
  case CURLINFO_SSL_DATA_OUT:
    text = "=> Send SSL data";
    break;
  case CURLINFO_HEADER_IN:
    text = "<= Recv header";
    break;
  case CURLINFO_DATA_IN:
    text = "<= Recv data";
    break;
  case CURLINFO_SSL_DATA_IN:
    text = "<= Recv SSL data";
    break;
  }

  dump(text, stderr, (unsigned char *)data, size, config->trace_ascii);
  return 0;
}