Unverified Commit 130e2ffa authored by Deepesh Pathak's avatar Deepesh Pathak
Browse files

Remove duplicate code between parse_{c,s}method in transport.c 

- Merged common code in function parse_{c,s}method to a single function
- Removed duplicate code in transport.c
- Fixes #6236
parent f6a230ec

changes/ticket6236

0 → 100644
+4 −0
Original line number Diff line number Diff line 
  o Minor bugfixes (Duplicate code):

    - Remove duplicate code in parse_{c,s}method_line and bootstrap

      their functionalities into a single function. Fixes

      bug 6236; bugfix on 0.2.3.6-alpha.

src/or/transports.c

+71 −111
Original line number Diff line number Diff line
@@ -1025,48 +1025,71 @@ parse_method_error(const char *line, int is_server) 
           line+strlen(error)+1);

}



/** Parses an SMETHOD <b>line</b> and if well-formed it registers the

 *  new transport in <b>mp</b>. */

STATIC int

parse_smethod_line(const char *line, managed_proxy_t *mp)

/** A helper for parse_{c,s}method_line(), bootstraps its

 *  functionalities. If <b>is_smethod</b> is true then the

 *  the line to parse is a SMETHOD line otherwise it is a

 *  CMETHOD line*/

static int

parse_method_line_helper(const char *line,

                         managed_proxy_t *mp,

                         int is_smethod)

{

  int item_index = 0;

  int r;

  smartlist_t *items = NULL;



  char *method_name=NULL;

  char *transport_name=NULL;

  char *args_string=NULL;

  char *addrport=NULL;

  tor_addr_t tor_addr;

  int socks_ver=PROXY_NONE;

  char *address=NULL;

  uint16_t port = 0;



  const char *method_str = is_smethod ? PROTO_SMETHOD : PROTO_CMETHOD;

  const int min_args_count = is_smethod ? 3 : 4;



  tor_addr_t tor_addr;

  transport_t *transport=NULL;

  smartlist_t *items= smartlist_new();



  items = smartlist_new();

  smartlist_split_string(items, line, NULL,

                         SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, -1);

  if (smartlist_len(items) < 3) {

    log_warn(LD_CONFIG, "Server managed proxy sent us a SMETHOD line "

             "with too few arguments.");

  if (smartlist_len(items) < min_args_count) {

    log_warn(LD_CONFIG, "Managed proxy sent us a %s line "

             "with too few arguments.", method_str);

    goto err;

  }



  /* Example of legit SMETHOD line:

     SMETHOD obfs2 0.0.0.0:25612 ARGS:secret=supersekrit,key=superkey */



  tor_assert(!strcmp(smartlist_get(items,0),PROTO_SMETHOD));

  tor_assert(!strcmp(smartlist_get(items, item_index),method_str));

  ++item_index;



  method_name = smartlist_get(items,1);

  if (!string_is_C_identifier(method_name)) {

  transport_name = smartlist_get(items,item_index);

  ++item_index;

  if (!string_is_C_identifier(transport_name)) {

    log_warn(LD_CONFIG, "Transport name is not a C identifier (%s).",

             method_name);

             transport_name);

    goto err;

  }



  /** Check for the proxy method sent to us in CMETHOD line. */

  if (!is_smethod) {

    const char *socks_ver_str = smartlist_get(items,item_index);

    ++item_index;



    if (!strcmp(socks_ver_str,"socks4")) {

      socks_ver = PROXY_SOCKS4;

    } else if (!strcmp(socks_ver_str,"socks5")) {

      socks_ver = PROXY_SOCKS5;

    } else {

      log_warn(LD_CONFIG, "Client managed proxy sent us a proxy protocol "

               "we don't recognize. (%s)", socks_ver_str);

      goto err;

    }

  }



  addrport = smartlist_get(items, 2);

  addrport = smartlist_get(items, item_index);

  ++item_index;

  if (tor_addr_port_split(LOG_WARN, addrport, &address, &port)<0) {

    log_warn(LD_CONFIG, "Error parsing transport "

             "address '%s'", addrport);

    log_warn(LD_CONFIG, "Error parsing transport address '%s'", addrport);

    goto err;

  }
@@ -1081,10 +1104,11 @@ parse_smethod_line(const char *line, managed_proxy_t *mp) 
    goto err;

  }



  if (smartlist_len(items) > 3) {

  /** Check for options in the SMETHOD line. */

  if (is_smethod && smartlist_len(items) > min_args_count) {

    /* Seems like there are also some [options] in the SMETHOD line.

       Let's see if we can parse them. */

    char *options_string = smartlist_get(items, 3);

    char *options_string = smartlist_get(items, item_index);

    log_debug(LD_CONFIG, "Got options_string: %s", options_string);

    if (!strcmpstart(options_string, "ARGS:")) {

      args_string = options_string+strlen("ARGS:");
@@ -1092,15 +1116,20 @@ parse_smethod_line(const char *line, managed_proxy_t *mp) 
    }

  }



  transport = transport_new(&tor_addr, port, method_name,

                            PROXY_NONE, args_string);

  transport = transport_new(&tor_addr, port, transport_name,

                            socks_ver, args_string);



  smartlist_add(mp->transports, transport);



  /* For now, notify the user so that they know where the server

     transport is listening. */

  /** Logs info about line parsing success for client or server */

  if (is_smethod) {

    log_info(LD_CONFIG, "Server transport %s at %s:%d.",

           method_name, address, (int)port);

             transport_name, address, (int)port);

  } else {

    log_info(LD_CONFIG, "Transport %s at %s:%d with SOCKS %d. "

             "Attached to managed proxy.",

             transport_name, address, (int)port, socks_ver);

  }



  r=0;

  goto done;
@@ -1115,93 +1144,24 @@ parse_smethod_line(const char *line, managed_proxy_t *mp) 
  return r;

}



/** Parses an SMETHOD <b>line</b> and if well-formed it registers the

 *  new transport in <b>mp</b>. */

STATIC int

parse_smethod_line(const char *line, managed_proxy_t *mp)

{

  /* Example of legit SMETHOD line:

     SMETHOD obfs2 0.0.0.0:25612 ARGS:secret=supersekrit,key=superkey */

  return parse_method_line_helper(line, mp, 1);

}



/** Parses a CMETHOD <b>line</b>, and if well-formed it registers

 *  the new transport in <b>mp</b>. */

STATIC int

parse_cmethod_line(const char *line, managed_proxy_t *mp)

{

  int r;

  smartlist_t *items = NULL;



  char *method_name=NULL;



  char *socks_ver_str=NULL;

  int socks_ver=PROXY_NONE;



  char *addrport=NULL;

  tor_addr_t tor_addr;

  char *address=NULL;

  uint16_t port = 0;



  transport_t *transport=NULL;



  items = smartlist_new();

  smartlist_split_string(items, line, NULL,

                         SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, -1);

  if (smartlist_len(items) < 4) {

    log_warn(LD_CONFIG, "Client managed proxy sent us a CMETHOD line "

             "with too few arguments.");

    goto err;

  }



  tor_assert(!strcmp(smartlist_get(items,0),PROTO_CMETHOD));



  method_name = smartlist_get(items,1);

  if (!string_is_C_identifier(method_name)) {

    log_warn(LD_CONFIG, "Transport name is not a C identifier (%s).",

             method_name);

    goto err;

  }



  socks_ver_str = smartlist_get(items,2);



  if (!strcmp(socks_ver_str,"socks4")) {

    socks_ver = PROXY_SOCKS4;

  } else if (!strcmp(socks_ver_str,"socks5")) {

    socks_ver = PROXY_SOCKS5;

  } else {

    log_warn(LD_CONFIG, "Client managed proxy sent us a proxy protocol "

             "we don't recognize. (%s)", socks_ver_str);

    goto err;

  }



  addrport = smartlist_get(items, 3);

  if (tor_addr_port_split(LOG_WARN, addrport, &address, &port)<0) {

    log_warn(LD_CONFIG, "Error parsing transport "

             "address '%s'", addrport);

    goto err;

  }



  if (!port) {

    log_warn(LD_CONFIG,

             "Transport address '%s' has no port.", addrport);

    goto err;

  }



  if (tor_addr_parse(&tor_addr, address) < 0) {

    log_warn(LD_CONFIG, "Error parsing transport address '%s'", address);

    goto err;

  }



  transport = transport_new(&tor_addr, port, method_name, socks_ver, NULL);



  smartlist_add(mp->transports, transport);



  log_info(LD_CONFIG, "Transport %s at %s:%d with SOCKS %d. "

           "Attached to managed proxy.",

           method_name, address, (int)port, socks_ver);



  r=0;

  goto done;



 err:

  r = -1;



 done:

  SMARTLIST_FOREACH(items, char*, s, tor_free(s));

  smartlist_free(items);

  tor_free(address);

  return r;

  /* Example of legit CMETHOD line:

     CMETHOD obfs2 socks5 127.0.0.1:35713 */

  return parse_method_line_helper(line, mp, 0);

}



/** Parses an PROXY-ERROR <b>line</b> and warns the user accordingly. */