ftp_funcs.c

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/* SPDX-FileCopyrightText: 2023 Greenbone AG
 * SPDX-FileCopyrightText: 1998 Renaud Deraison
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */
 
#include "ftp_funcs.h"
 
#include "network.h"
 
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
int
ftp_log_in (int soc, char *username, char *passwd)
{
  char buf[1024];
  int n;
  int counter;
 
  buf[sizeof (buf) - 1] = '\0';
  n = recv_line (soc, buf, sizeof (buf) - 1);
  if (n <= 0)
    return (1);
 
  if (strncmp (buf, "220", 3) != 0)
    {
      return 1;
    }
 
  counter = 0;
  while (buf[3] == '-' && n > 0 && counter < 1024)
    {
      n = recv_line (soc, buf, sizeof (buf) - 1);
      counter++;
    }
 
  if (counter >= 1024)
    return 1; /* Rogue FTP server */
 
  if (n <= 0)
    return 1;
 
  snprintf (buf, sizeof (buf), "USER %s\r\n", username);
  write_stream_connection (soc, buf, strlen (buf));
  n = recv_line (soc, buf, sizeof (buf) - 1);
  if (n <= 0)
    return 1;
  if (strncmp (buf, "230", 3) == 0)
    {
      counter = 0;
      while (buf[3] == '-' && n > 0 && counter < 1024)
        {
          n = recv_line (soc, buf, sizeof (buf) - 1);
          counter++;
        }
      return 0;
    }
 
  if (strncmp (buf, "331", 3) != 0)
    {
      return 1;
    }
 
  counter = 0;
  n = 1;
  while (buf[3] == '-' && n > 0 && counter < 1024)
    {
      n = recv_line (soc, buf, sizeof (buf) - 1);
      counter++;
    }
 
  if (counter >= 1024)
    return 1;
 
  snprintf (buf, sizeof (buf), "PASS %s\r\n", passwd);
  write_stream_connection (soc, buf, strlen (buf));
  n = recv_line (soc, buf, sizeof (buf) - 1);
  if (n <= 0)
    return 1;
 
  if (strncmp (buf, "230", 3) != 0)
    {
      return 1;
    }
 
  counter = 0;
  n = 1;
  while (buf[3] == '-' && n > 0 && counter < 1024)
    {
      n = recv_line (soc, buf, sizeof (buf) - 1);
      counter++;
    }
 
  return 0;
}
 
int
ftp_get_pasv_address (int soc, struct sockaddr_in *addr)
{
  char buf[512];
  char *t, *s;
  unsigned char l[6];
  uint32_t *a;
  unsigned short *p;
 
  snprintf (buf, 7, "PASV\r\n");
  write_stream_connection (soc, buf, strlen (buf));
  bzero (buf, sizeof (buf));
  bzero (addr, sizeof (struct sockaddr_in));
  if (recv_line (soc, buf, sizeof (buf) - 1) < 0)
    return 1;
 
  if (strncmp (buf, "227", 3) != 0)
    return 1;
 
  t = strchr (buf, '(');
  if (t == NULL)
    return 1;
  t++;
  s = strchr (t, ',');
  if (s == NULL)
    return 1;
 
  s[0] = '\0';
 
  l[0] = (unsigned char) atoi (t);
  s++;
  t = strchr (s, ',');
  if (t == NULL)
    return 1;
  t[0] = 0;
  l[1] = (unsigned char) atoi (s);
  t++;
  s = strchr (t, ',');
  if (s == NULL)
    return 1;
  s[0] = 0;
  l[2] = (unsigned char) atoi (t);
  s++;
  t = strchr (s, ',');
  if (t == NULL)
    return 1;
  t[0] = 0;
  l[3] = (unsigned char) atoi (s);
  t++;
  s = strchr (t, ',');
  if (s == NULL)
    return 1;
  s[0] = 0;
  l[4] = (unsigned char) atoi (t);
  s++;
  t = strchr (s, ')');
  if (t == NULL)
    return 1;
  t[0] = 0;
  l[5] = (unsigned char) atoi (s);
  a = (uint32_t *) l;
  p = (unsigned short *) (l + 4);
 
  addr->sin_addr.s_addr = *a;
  addr->sin_port = *p;
  addr->sin_family = AF_INET;
  return 0;
}