gdbsupport/netstuff.cc

   1 /* Operations on network stuff.
   2    Copyright (C) 2018-2023 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   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 3 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, see <http://www.gnu.org/licenses/>.  */
  18
  19 #include "common-defs.h"
  20 #include "netstuff.h"
  21 #include <algorithm>
  22
  23 #ifdef USE_WIN32API
  24 #include <ws2tcpip.h>
  25 #else
  26 #include <netinet/in.h>
  27 #include <arpa/inet.h>
  28 #include <netdb.h>
  29 #include <sys/socket.h>
  30 #include <netinet/tcp.h>
  31 #endif
  32
  33 /* See gdbsupport/netstuff.h.  */
  34
  35 scoped_free_addrinfo::~scoped_free_addrinfo ()
  36 {
  37   freeaddrinfo (m_res);
  38 }
  39
  40 /* See gdbsupport/netstuff.h.  */
  41
  42 parsed_connection_spec
  43 parse_connection_spec_without_prefix (std::string spec, struct addrinfo *hint)
  44 {
  45   parsed_connection_spec ret;
  46   size_t last_colon_pos = 0;
  47   /* We're dealing with IPv6 if:
  48
  49      - ai_family is AF_INET6, or
  50      - ai_family is not AF_INET, and
  51        - spec[0] is '[', or
  52        - the number of ':' on spec is greater than 1.  */
  53   bool is_ipv6 = (hint->ai_family == AF_INET6
  54                   || (hint->ai_family != AF_INET
  55                       && (spec[0] == '['
  56                           || std::count (spec.begin (),
  57                                          spec.end (), ':') > 1)));
  58
  59   if (is_ipv6)
  60     {
  61       if (spec[0] == '[')
  62         {
  63           /* IPv6 addresses can be written as '[ADDR]:PORT', and we
  64              support this notation.  */
  65           size_t close_bracket_pos = spec.find_first_of (']');
  66
  67           if (close_bracket_pos == std::string::npos)
  68             error (_("Missing close bracket in hostname '%s'"),
  69                    spec.c_str ());
  70
  71           hint->ai_family = AF_INET6;
  72
  73           const char c = spec[close_bracket_pos + 1];
  74
  75           if (c == '\0')
  76             last_colon_pos = std::string::npos;
  77           else if (c != ':')
  78             error (_("Invalid cruft after close bracket in '%s'"),
  79                    spec.c_str ());
  80
  81           /* Erase both '[' and ']'.  */
  82           spec.erase (0, 1);
  83           spec.erase (close_bracket_pos - 1, 1);
  84         }
  85       else if (spec.find_first_of (']') != std::string::npos)
  86         error (_("Missing open bracket in hostname '%s'"),
  87                spec.c_str ());
  88     }
  89
  90   if (last_colon_pos == 0)
  91     last_colon_pos = spec.find_last_of (':');
  92
  93   /* The length of the hostname part.  */
  94   size_t host_len;
  95
  96   if (last_colon_pos != std::string::npos)
  97     {
  98       /* The user has provided a port.  */
  99       host_len = last_colon_pos;
 100       ret.port_str = spec.substr (last_colon_pos + 1);
 101     }
 102   else
 103     host_len = spec.size ();
 104
 105   ret.host_str = spec.substr (0, host_len);
 106
 107   /* Default hostname is localhost.  */
 108   if (ret.host_str.empty ())
 109     ret.host_str = "localhost";
 110
 111   return ret;
 112 }
 113
 114 /* See gdbsupport/netstuff.h.  */
 115
 116 parsed_connection_spec
 117 parse_connection_spec (const char *spec, struct addrinfo *hint)
 118 {
 119   /* Struct to hold the association between valid prefixes, their
 120      family and socktype.  */
 121   struct host_prefix
 122     {
 123       /* The prefix.  */
 124       const char *prefix;
 125
 126       /* The 'ai_family'.  */
 127       int family;
 128
 129       /* The 'ai_socktype'.  */
 130       int socktype;
 131     };
 132   static const struct host_prefix prefixes[] =
 133     {
 134       { "udp:",  AF_UNSPEC, SOCK_DGRAM },
 135       { "tcp:",  AF_UNSPEC, SOCK_STREAM },
 136       { "udp4:", AF_INET,   SOCK_DGRAM },
 137       { "tcp4:", AF_INET,   SOCK_STREAM },
 138       { "udp6:", AF_INET6,  SOCK_DGRAM },
 139       { "tcp6:", AF_INET6,  SOCK_STREAM },
 140     };
 141
 142   for (const host_prefix prefix : prefixes)
 143     if (startswith (spec, prefix.prefix))
 144       {
 145         spec += strlen (prefix.prefix);
 146         hint->ai_family = prefix.family;
 147         hint->ai_socktype = prefix.socktype;
 148         hint->ai_protocol
 149           = hint->ai_socktype == SOCK_DGRAM ? IPPROTO_UDP : IPPROTO_TCP;
 150         break;
 151       }
 152
 153   return parse_connection_spec_without_prefix (spec, hint);
 154 }