path: root/src/net.c

/*
   net.c

   This file is part of GNU Anubis.
   Copyright (C) 2001-2024 The Anubis Team.

   GNU Anubis is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published by the
   Free Software Foundation; either version 3 of the License, or (at your
   option) any later version.

   GNU Anubis is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License along
   with GNU Anubis.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "headers.h"
#include "extern.h"

static int connect_directly_to (char *, unsigned int);

static struct _debug_cache
{
  int method;
  int output;
  int newline;
  size_t count;
}
debug_cache =
{
-1, -1, 0, 0};

static void
_debug_printer (int method, int output, unsigned long nleft, const char *ptr)
{
  int i;
  char *mode = "?";

  switch (method)
    {
    case CLIENT:
      mode = _("SERVER");
      break;
    case SERVER:
      mode = _("CLIENT");
    }

  if (debug_cache.newline
      || method != debug_cache.method || output != debug_cache.output)
    {
      if (!debug_cache.newline && debug_cache.count)
	fprintf (stderr, "(%lu)\n", (unsigned long) debug_cache.count);
      debug_cache.method = method;
      debug_cache.output = output;
      debug_cache.newline = 0;
      debug_cache.count = 0;
      fprintf (stderr, "%s %s ", mode, output ? "<<<" : ">>>");
    }

  for (i = 0; i < nleft; i++, ptr++)
    {
      debug_cache.count++;
      debug_cache.newline = 0;
      if (*ptr == '\r')
	continue;
      if (*ptr == '\n')
	{
	  fprintf (stderr, "(%ld)\n", (unsigned long) debug_cache.count);
	  debug_cache.count = 0;
	  if (i != nleft - 1)
	    {
	      fprintf (stderr, "%s %s ", mode, output ? "<<<" : ">>>");
	      debug_cache.newline = 0;
	    }
	  else
	    debug_cache.newline = 1;
	}
      else
	fputc (*ptr, stderr);
    }
}

#define DPRINTF(method, output, nleft, ptr) do {\
  if (options.termlevel == DEBUG) \
     _debug_printer(method, output, nleft, ptr);\
  } while (0)

NET_STREAM
make_remote_connection (char *host, unsigned int port)
{
  int sd;
  NET_STREAM str;

#ifdef USE_SOCKS_PROXY
  if (topt & T_SOCKS)
    {				/* SOCKS proxy */
      host = session.socks;
      port = session.socks_port;
    }
#endif /* USE_SOCKS_PROXY */

  if ((sd = connect_directly_to (host, port)) == -1)
    return NULL;

  net_create_stream (&str, sd);
  return str;
}

static int
connect_directly_to (char *host, unsigned int port)
{
  int sd = 0;
  unsigned long inaddr;
  struct sockaddr_in addr;

  /*
     Find out the IP address.
   */

  memset (&addr, 0, sizeof (addr));
  addr.sin_family = AF_INET;
  addr.sin_port = htons (port);
  info (VERBOSE, _("Getting remote host information..."));

  inaddr = inet_addr (host);
  if (inaddr != INADDR_NONE)
    memcpy (&addr.sin_addr, &inaddr, sizeof (inaddr));
  else
    {
      struct hostent *hp = 0;
      hp = gethostbyname (host);
      if (hp == 0)
	{
	  hostname_error (host);
	  return -1;
	}
      else
	{
	  if (hp->h_length != 4 && hp->h_length != 8)
	    {
	      anubis_error (EXIT_FAILURE, 0,
			    _("Illegal address length received for host %s"),
			    host);
	      return -1;
	    }
	  else
	    {
	      memcpy ((char *) &addr.sin_addr.s_addr, hp->h_addr,
		      hp->h_length);
	    }
	}
    }

  /*
     Create socket, and connect.
   */

  if ((sd = socket (AF_INET, SOCK_STREAM, 0)) == -1)
    {
      anubis_error (EXIT_FAILURE, errno, _("Cannot create stream socket."));
      return -1;
    }
  if (connect (sd, (struct sockaddr *) &addr, sizeof (addr)) == -1)
    {
      anubis_error (EXIT_FAILURE, errno, _("Couldn't connect to %s:%u. %s."),
		    host, port, strerror (errno));
      return -1;
    }
  else
    info (NORMAL, _("Connected to %s:%u"), host, port);

  return sd;
}

/*****************
 Bind and listen.
******************/

int
bind_and_listen (char *host, unsigned int port)
{
  int sd = 0;
  unsigned long inaddr;
  struct sockaddr_in addr;
  int t = 1;

  memset (&addr, 0, sizeof (addr));
  addr.sin_family = AF_INET;
  addr.sin_port = htons (port);

  if ((sd = socket (AF_INET, SOCK_STREAM, 0)) == -1)
    anubis_error (EXIT_FAILURE, errno, _("Cannot create stream socket"));

  if (topt & T_NAMES)
    {
      inaddr = inet_addr (host);
      if (inaddr != INADDR_NONE)
	memcpy (&addr.sin_addr, &inaddr, sizeof (inaddr));
      else
	{
	  struct hostent *hp = 0;
	  hp = gethostbyname (host);
	  if (hp == 0)
	    hostname_error (host);
	  else
	    {
	      if (hp->h_length != 4 && hp->h_length != 8)
		anubis_error (EXIT_FAILURE, 0,
			      _("Illegal address length received for host %s"),
			      host);
	      else
		{
		  memcpy ((char *) &addr.sin_addr.s_addr, hp->h_addr,
			  hp->h_length);
		}
	    }
	}
    }
  else
    addr.sin_addr.s_addr = htonl (INADDR_ANY);

  setsockopt (sd, SOL_SOCKET, SO_REUSEADDR, &t, sizeof (t));

  if (bind (sd, (struct sockaddr *) &addr, sizeof (addr)))
    anubis_error (EXIT_FAILURE, errno, _("bind() failed"));
  info (VERBOSE, _("GNU Anubis bound to %s:%u"), inet_ntoa (addr.sin_addr),
	ntohs (addr.sin_port));
  if (listen (sd, 5))
    anubis_error (EXIT_FAILURE, errno, _("listen() failed"));
  return sd;
}

/**************
  Send a data
***************/

void
swrite_n (int method, NET_STREAM sd, const char *ptr, size_t nleft)
{
  int rc;
  size_t nwritten = 0;

  if (nleft == 0)
    return;
  rc = stream_write (sd, ptr, nleft, &nwritten);
  if (rc)
    socket_error (stream_strerror (sd, rc));
  DPRINTF (method, 1, nwritten, ptr);
  if (nwritten != nleft)
    {
      /* Should not happen */
      anubis_error (EXIT_FAILURE, 0, _("Short write"));
    }
}

void
swrite (int method, NET_STREAM sd, const char *ptr)
{
  size_t nleft;
  
  if (ptr == NULL || (nleft = strlen (ptr)) == 0)
    return;
  swrite_n (method, sd, ptr, nleft);
}

void
send_eol (int method, NET_STREAM sd)
{
  swrite (method, sd,
	  (anubis_mode == anubis_mda && (topt & T_LOCAL_MTA)) ? "\n" : CRLF);
}

/**************
  Read data
***************/

int
recvline (int method, NET_STREAM sd, char **vptr, size_t *maxlen)
{
  size_t nread;
  int rc = stream_getline (sd, vptr, maxlen, &nread);

  if (rc)
    socket_error (stream_strerror (sd, rc));
  DPRINTF (method, 0, nread, *vptr);
  return nread;
}

/*****************
  Get a response
******************/

struct net_reader_closure
{
  int method;
  NET_STREAM stream;
};
  
static ssize_t
_net_reader (void *data, char **sptr, size_t *psize)
{
  struct net_reader_closure *np = data;
  return recvline (np->method, np->stream, sptr, psize);
}

void
smtp_reply_get (int method, NET_STREAM sd, ANUBIS_SMTP_REPLY reply)
{
  struct net_reader_closure clos;

  clos.method = method;
  clos.stream = sd;
  smtp_reply_read (reply, _net_reader, &clos);
}

/**************************
 Close a socket descriptor
***************************/
void
close_socket (int sd)
{
  if (sd)
    close (sd);
  return;
}

void
net_close_stream (NET_STREAM *sd)
{
  stream_close (*sd);
  stream_destroy (sd);
  return;
}


void
net_create_stream (NET_STREAM * str, int fd)
{
  stream_create (str);
  stream_set_io (*str, (void *) (ptrdiff_t) fd, NULL, NULL, NULL, NULL, NULL);
}


/* EOF */