wmnotify/src/imap.c

   1 /*
   2  * imap.c -- Routines for communication with an IMAP server
   3  *
   4  * Copyright (C) 2003 Hugo Villeneuve <hugo@hugovil.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
  19  */
  20
  21 /* Define filename_M */
  22 #define IMAP_M 1
  23
  24 #if HAVE_CONFIG_H
  25 #  include "config.h"
  26 #endif
  27
  28 #include <stdio.h>
  29 #include <unistd.h>
  30 #include <stdlib.h>
  31 #include <sys/types.h>
  32 #include <sys/wait.h>
  33 #include <sys/socket.h>
  34 #include <netinet/in.h>
  35 #include <netdb.h>
  36 #include <arpa/inet.h>
  37 #include <ctype.h> /* for isdigit() */
  38
  39 #include "common.h"
  40 #include "wmnotify.h"
  41 #include "network.h"
  42 #include "imap.h"
  43
  44
  45 #define IMAP4_ENDL "\r\n" /* CRLF */
  46
  47 #define IMAP4_CMD_CAPABILITY    "CAPABILITY"
  48 #define IMAP4_CMD_LOGIN         "LOGIN"
  49 #define IMAP4_CMD_SELECT        "SELECT"
  50 #define IMAP4_CMD_EXAMINE       "EXAMINE"
  51 #define IMAP4_CMD_LOGOUT        "LOGOUT"
  52 #define IMAP4_CMD_SEARCH_UNSEEN "SEARCH UNSEEN"
  53
  54 /* Responses from IMAP4 server. */
  55 #define IMAP4_RSP_SUCCESS      "OK"
  56 #define IMAP4_RSP_FAILURE      "NO"
  57 #define IMAP4_RSP_PROTOCOL_ERR "BAD"
  58 #define IMAP4_RSP_SEARCH_UNSEEN "* SEARCH " /* This is the line that will be returned by
  59                                              * the IMAP4 server after receiving the
  60                                              * "SEARCH UNSEEN" command, followed by the
  61                                              * messages ID of the unseen messages. */
  62
  63
  64 static int tlabel = 0;
  65 static int tlabel_len;
  66 static int unseen_string_found;
  67
  68 /* Defined in network.c */
  69 extern char tx_buffer[WMNOTIFY_BUFSIZE + 1];
  70 extern char rx_buffer[WMNOTIFY_BUFSIZE + 1];
  71
  72
  73 static int
  74 IMAP4_ReceiveResponse( void )
  75 {
  76   int len;
  77   char *token;
  78   char *stringp;
  79
  80   /* All interactions transmitted by client and server are in the form of
  81      lines, that is, strings that end with a CRLF.  The protocol receiver
  82      of an IMAP4rev1 client or server is either reading a line, or is
  83      reading a sequence of octets with a known count followed by a line. */
  84
  85  get_packet:
  86   len = WmnotifyGetResponse( rx_buffer, WMNOTIFY_BUFSIZE );
  87   if( len < 0 ) {
  88     /* An error occured. WmnotifyGetResponse() should have printed an error message. */
  89     goto error;
  90   }
  91   else if( len == 0 ) {
  92     /* The return value will be 0 when the peer has performed an orderly shutdown. */
  93     if( wmnotify_infos.debug ) {
  94       fprintf( stderr, "IMAP server has closed connection.\n" );
  95     }
  96     goto error;
  97   }
  98   else if( len == WMNOTIFY_BUFSIZE ) {
  99     if( wmnotify_infos.debug ) {
 100       ErrorLocation( __FILE__, __LINE__ );
 101       fprintf( stderr, "Response too big (%d bytes) to fit in receive buffer.\n", len );
 102     }
 103     goto error;
 104   }
 105
 106   /* We suppose that, if a partial response packet was sent, it is not broken in the middle
 107      of a line (to confirm). Normally, each string is terminated by CRLF. */
 108   if( STREQ_LEN( &rx_buffer[ len - 2 ], IMAP4_ENDL, 2 ) == false ) {
 109     /* No CRLF found at the end of the buffer --> not handled by wmnotify. */
 110     ErrorLocation( __FILE__, __LINE__ );
 111     fprintf( stderr, "Response buffer doesn't contain CRLF at the end.\n" );
 112     goto error;
 113   }
 114
 115   if( wmnotify_infos.debug ) {
 116     printf( "<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n" );
 117     printf( "IMAP4 Server Response (size %d bytes):\n", len );
 118     printf( "%s", rx_buffer );
 119     printf( "<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n" );
 120   }
 121
 122   /* Converting the last CRLF into a LF followed by a NULL termination character. */
 123   rx_buffer[ len - 2 ] = '\n';
 124   rx_buffer[ len - 1 ] = '\0';
 125
 126   /* Check the Server Completion Response returned by the IMAP4 server. There are currently
 127    * three Server Completion Responses codes: success ("OK"), failure ("NO") and protocol error
 128    * ("BAD"). */
 129   stringp = rx_buffer;
 130
 131   while( ( token = strsep( &stringp, "\n" ) ) != NULL ) {
 132
 133     /* In case no delimiter was found, the token is  taken  to
 134        be the entire string *stringp, and *stringp is made NULL. */
 135     if( stringp == NULL ) {
 136       if( token[0] == '\0' ) {
 137         /* This means we finished parsing the last line of the buffer, but we need to
 138            get more data to continue process the next part of the IMAP4 response. */
 139         goto get_packet;
 140       }
 141       else {
 142         /* This should never happen. */
 143         ErrorLocation( __FILE__, __LINE__ );
 144         fprintf( stderr, "  Delimiter not found in strsep() call.\n" );
 145         goto error;
 146       }
 147     }
 148
 149     if( token == NULL ) {
 150       /* This should never happen. */
 151       ErrorLocation( __FILE__, __LINE__ );
 152       fprintf( stderr, "  NULL token returned by strsep().\n" );
 153       goto error;
 154     }
 155
 156     if( token[0] == '*' ) {
 157       /* Untagged response. If there is a space after the SEARCH response, it means
 158        * at least 1 message is unseen. */
 159       if( STREQ_LEN( token, IMAP4_RSP_SEARCH_UNSEEN, strlen(IMAP4_RSP_SEARCH_UNSEEN) ) == true ) {
 160         unseen_string_found = true;
 161       }
 162     }
 163     else {
 164       /* Must be the status... */
 165
 166       /* We check for the correct transaction label plus a space. */
 167       if( STREQ_LEN( token, tx_buffer, tlabel_len + 1 ) == true ) {
 168         token += tlabel_len + 1;
 169         if( STREQ_LEN( token, IMAP4_RSP_SUCCESS, strlen(IMAP4_RSP_SUCCESS) ) == true ) {
 170           goto end; /* OK, no errors. */
 171         }
 172         else if( STREQ_LEN( token, IMAP4_RSP_PROTOCOL_ERR, strlen(IMAP4_RSP_PROTOCOL_ERR) ) == true ) {
 173           fprintf( stderr, "%s: Protocol error (%s).\n", PACKAGE, token );
 174           goto error;
 175         }
 176         else if( STREQ_LEN( token, IMAP4_RSP_FAILURE, strlen(IMAP4_RSP_FAILURE) ) == true ) {
 177           fprintf( stderr, "%s: Failure (%s).\n", PACKAGE, token );
 178           goto error;
 179         }
 180         else {
 181           fprintf( stderr, "%s: Unknown error code (%s).\n", PACKAGE, token );
 182           goto error;
 183         }
 184       }
 185       else {
 186         fprintf( stderr, "%s: Error, transaction label mismatch.\n", PACKAGE );
 187         goto error;
 188       }
 189     }
 190   } /* while( token ) */
 191
 192   /* Get next part of IMAP4 response. */
 193   goto get_packet;
 194
 195  end:
 196   /* No error. */
 197   return len;
 198
 199  error:
 200   return -1;
 201 }
 202
 203
 204 static int
 205 IMAP4_SendCommand( int argc, char *argv[] )
 206 {
 207   int len;
 208   int i;
 209
 210   /* Adding Transaction Label. */
 211   tlabel++;
 212   tx_buffer[0] = 'A';
 213   len = 1;
 214   len += sprintf( tx_buffer + len, "%d", tlabel );
 215   tlabel_len = len;
 216
 217   /* Adding command and it's arguments. */
 218   for( i = 0; i < argc; i++ ) {
 219     len += sprintf( tx_buffer + len, " %s", argv[i] );
 220   }
 221
 222   if( wmnotify_infos.debug ) {
 223     tx_buffer[len] = '\0';
 224     printf( ">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n" );
 225     printf( "IMAP4 Client Command (size %d bytes):\n%s\n", len, tx_buffer );
 226     printf( ">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n" );
 227   }
 228
 229   /* Adding termination characters. */
 230   len += sprintf( tx_buffer + len, IMAP4_ENDL );
 231
 232   len = WmnotifySendData( tx_buffer, len );
 233   if( len < 0 ) {
 234     return EXIT_FAILURE;
 235   }
 236
 237   len = IMAP4_ReceiveResponse();
 238   if( len < 0 ) {
 239     return EXIT_FAILURE;
 240   }
 241
 242   return EXIT_SUCCESS;
 243 }
 244
 245
 246 int
 247 IMAP4_CheckForNewMail( void )
 248 {
 249   char *argv[10];
 250   int new_messages = 0;
 251   int status;
 252
 253   status = ConnectionEstablish( wmnotify_infos.server_name, wmnotify_infos.port );
 254   if( status != EXIT_SUCCESS ) {
 255     new_messages = -1;
 256     goto end;
 257   }
 258
 259   argv[0] = IMAP4_CMD_LOGIN;
 260   argv[1] = wmnotify_infos.username;
 261   argv[2] = wmnotify_infos.password;
 262   status = IMAP4_SendCommand( 3, argv );
 263   if( status != EXIT_SUCCESS ) {
 264     new_messages = -1;
 265     goto imap4_logout;
 266   }
 267
 268   /* Selecting the mailbox first. */
 269   argv[0] = IMAP4_CMD_EXAMINE;
 270   argv[1] = wmnotify_infos.imap_folder;
 271   status = IMAP4_SendCommand( 2, argv );
 272   if( status != EXIT_SUCCESS ) {
 273     new_messages = -1;
 274     goto imap4_logout;
 275   }
 276
 277   /* Searching in selected mailbox for new messages. We must use the UNSEEN search criteria
 278    * instead of NEW (combination of RECENT and UNSEEN). If there is a new message, RECENT
 279    * and UNSEEN will have entries. But if we recheck again later, RECENT will report zero.
 280    * RECENT, when set, simply means that there are new messages since our last visit.
 281      But, on the other hand, when using EXAMINE, no messages should lose their RECENT flag. */
 282   unseen_string_found = false;
 283   argv[0] = IMAP4_CMD_SEARCH_UNSEEN;
 284   argv[1] = "";
 285   status = IMAP4_SendCommand( 1, argv );
 286   if( status != EXIT_SUCCESS ) {
 287     new_messages = -1;
 288     goto imap4_logout;
 289   }
 290
 291   if( unseen_string_found == true ) {
 292     new_messages = 1;
 293   }
 294
 295  imap4_logout:
 296   argv[0] = IMAP4_CMD_LOGOUT;
 297   status = IMAP4_SendCommand( 1, argv );
 298   if( status != EXIT_SUCCESS ) {
 299     new_messages = -1;
 300   }
 301
 302   status = ConnectionTerminate();
 303   if( status != EXIT_SUCCESS ) {
 304     new_messages = -1;
 305   }
 306
 307  end:
 308   return new_messages;
 309 }