gdbsupport/netstuff.cc

   1 /* Operations on network stuff.
   2    Copyright (C) 2018-2024 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 "netstuff.h"
  20 #include <algorithm>
  21
  22 #ifdef USE_WIN32API
  23 #include <ws2tcpip.h>
  24 #else
  25 #include <netinet/in.h>
  26 #include <arpa/inet.h>
  27 #include <netdb.h>
  28 #include <sys/socket.h>
  29 #include <netinet/tcp.h>
  30 #endif
  31
  32 /* See gdbsupport/netstuff.h.  */
  33
  34 scoped_free_addrinfo::~scoped_free_addrinfo ()
  35 {
  36   freeaddrinfo (m_res);
  37 }
  38
  39 /* See gdbsupport/netstuff.h.  */
  40
  41 parsed_connection_spec
  42 parse_connection_spec_without_prefix (std::string spec, struct addrinfo *hint)
  43 {
  44   parsed_connection_spec ret;
  45   size_t last_colon_pos = 0;
  46   /* We're dealing with IPv6 if:
  47
  48      - ai_family is AF_INET6, or
  49      - ai_family is not AF_INET, and
  50        - spec[0] is '[', or
  51        - the number of ':' on spec is greater than 1.  */
  52   bool is_ipv6 = (hint->ai_family == AF_INET6
  53                   || (hint->ai_family != AF_INET
  54                       && (spec[0] == '['
  55                           || std::count (spec.begin (),
  56                                          spec.end (), ':') > 1)));
  57
  58   if (is_ipv6)
  59     {
  60       if (spec[0] == '[')
  61         {
  62           /* IPv6 addresses can be written as '[ADDR]:PORT', and we
  63              support this notation.  */
  64           size_t close_bracket_pos = spec.find_first_of (']');
  65
  66           if (close_bracket_pos == std::string::npos)
  67             error (_("Missing close bracket in hostname '%s'"),
  68                    spec.c_str ());
  69
  70           hint->ai_family = AF_INET6;
  71
  72           const char c = spec[close_bracket_pos + 1];
  73
  74           if (c == '\0')
  75             last_colon_pos = std::string::npos;
  76           else if (c != ':')
  77             error (_("Invalid cruft after close bracket in '%s'"),
  78                    spec.c_str ());
  79
  80           /* Erase both '[' and ']'.  */
  81           spec.erase (0, 1);
  82           spec.erase (close_bracket_pos - 1, 1);
  83         }
  84       else if (spec.find_first_of (']') != std::string::npos)
  85         error (_("Missing open bracket in hostname '%s'"),
  86                spec.c_str ());
  87     }
  88
  89   if (last_colon_pos == 0)
  90     last_colon_pos = spec.find_last_of (':');
  91
  92   /* The length of the hostname part.  */
  93   size_t host_len;
  94
  95   if (last_colon_pos != std::string::npos)
  96     {
  97       /* The user has provided a port.  */
  98       host_len = last_colon_pos;
  99       ret.port_str = spec.substr (last_colon_pos + 1);
 100     }
 101   else
 102     host_len = spec.size ();
 103
 104   ret.host_str = spec.substr (0, host_len);
 105
 106   /* Default hostname is localhost.  */
 107   if (ret.host_str.empty ())
 108     ret.host_str = "localhost";
 109
 110   return ret;
 111 }
 112
 113 /* See gdbsupport/netstuff.h.  */
 114
 115 parsed_connection_spec
 116 parse_connection_spec (const char *spec, struct addrinfo *hint)
 117 {
 118   /* Struct to hold the association between valid prefixes, their
 119      family and socktype.  */
 120   struct host_prefix
 121     {
 122       /* The prefix.  */
 123       const char *prefix;
 124
 125       /* The 'ai_family'.  */
 126       int family;
 127
 128       /* The 'ai_socktype'.  */
 129       int socktype;
 130     };
 131   static const struct host_prefix prefixes[] =
 132     {
 133       { "udp:",  AF_UNSPEC, SOCK_DGRAM },
 134       { "tcp:",  AF_UNSPEC, SOCK_STREAM },
 135       { "udp4:", AF_INET,   SOCK_DGRAM },
 136       { "tcp4:", AF_INET,   SOCK_STREAM },
 137       { "udp6:", AF_INET6,  SOCK_DGRAM },
 138       { "tcp6:", AF_INET6,  SOCK_STREAM },
 139     };
 140
 141   for (const host_prefix prefix : prefixes)
 142     if (startswith (spec, prefix.prefix))
 143       {
 144         spec += strlen (prefix.prefix);
 145         hint->ai_family = prefix.family;
 146         hint->ai_socktype = prefix.socktype;
 147         hint->ai_protocol
 148           = hint->ai_socktype == SOCK_DGRAM ? IPPROTO_UDP : IPPROTO_TCP;
 149         break;
 150       }
 151
 152   return parse_connection_spec_without_prefix (spec, hint);
 153 }