1// CODYlib -*- mode:c++ -*-
2// Copyright (C) 2020 Nathan Sidwell, nathan@acm.org
3// License: Apache v2.0
4
5// Cody
6#include "internal.hh"
7#if CODY_NETWORKING
8// C
9#include <cerrno>
10#include <cstring>
11// OS
12#include <netdb.h>
13#include <unistd.h>
14#include <arpa/inet.h>
15#include <netinet/in.h>
16#include <sys/un.h>
17
18#ifndef AI_NUMERICSERV
19#define AI_NUMERICSERV 0
20#endif
21
22// Server-side networking helpers
23
24namespace Cody {
25
26int ListenSocket (char const **e, sockaddr const *addr, socklen_t len,
27 unsigned backlog)
28{
29 char const *errstr = nullptr;
30
31 int fd = socket (domain: addr->sa_family, SOCK_STREAM, protocol: 0);
32 if (fd < 0)
33 {
34 errstr = "creating socket";
35
36 fail:;
37 int err = errno;
38 if (e)
39 *e = errstr;
40 if (fd >= 0)
41 close (fd: fd);
42 errno = err;
43 return -1;
44 }
45
46 if (bind (fd: fd, addr: addr, len: len) < 0)
47 {
48 errstr = "binding socket";
49 goto fail;
50 }
51
52 if (listen (fd: fd, n: backlog ? backlog : 17) < 0)
53 {
54 errstr = "listening socket";
55 goto fail;
56 }
57
58 return fd;
59}
60
61int ListenLocal (char const **e, char const *name, unsigned backlog)
62{
63 sockaddr_un addr;
64 size_t len = strlen (s: name);
65
66 if (len >= sizeof (addr.sun_path))
67 {
68 errno = ENAMETOOLONG;
69 return -1;
70 }
71
72 memset (s: &addr, c: 0, offsetof (sockaddr_un, sun_path));
73 addr.sun_family = AF_UNIX;
74 memcpy (dest: addr.sun_path, src: name, n: len + 1);
75
76 return ListenSocket (e, addr: (sockaddr *)&addr, len: sizeof (addr), backlog);
77}
78
79int ListenInet6 (char const **e, char const *name, int port, unsigned backlog)
80{
81 addrinfo *addrs = nullptr;
82 int fd = -1;
83 char const *errstr = nullptr;
84
85 fd = socket (AF_INET6, SOCK_STREAM, protocol: 0);
86 if (fd < 0)
87 {
88 errstr = "creating socket";
89
90 fail:;
91 int err = errno;
92 if (e)
93 *e = errstr;
94 if (fd >= 0)
95 close (fd: fd);
96 if (addrs)
97 freeaddrinfo (ai: addrs);
98 errno = err;
99 return -1;
100 }
101
102 addrinfo hints;
103 hints.ai_flags = AI_NUMERICSERV;
104 hints.ai_family = AF_INET6;
105 hints.ai_socktype = SOCK_STREAM;
106 hints.ai_protocol = 0;
107 hints.ai_addrlen = 0;
108 hints.ai_addr = nullptr;
109 hints.ai_canonname = nullptr;
110 hints.ai_next = nullptr;
111
112 /* getaddrinfo requires a port number, but is quite happy to accept
113 invalid ones. So don't rely on it. */
114 if (int err = getaddrinfo (name: name, service: "0", req: &hints, pai: &addrs))
115 {
116 errstr = gai_strerror (ecode: err);
117 // What's the best errno to set?
118 errno = 0;
119 goto fail;
120 }
121
122 sockaddr_in6 addr;
123 memset (s: &addr, c: 0, n: sizeof (addr));
124 addr.sin6_family = AF_INET6;
125
126 for (struct addrinfo *next = addrs; next; next = next->ai_next)
127 if (next->ai_family == AF_INET6
128 && next->ai_socktype == SOCK_STREAM)
129 {
130 sockaddr_in6 *in6 = (sockaddr_in6 *)next->ai_addr;
131 in6->sin6_port = htons (port);
132 if (ntohs (in6->sin6_port) != port)
133 errno = EINVAL;
134 else if (!bind (fd: fd, addr: next->ai_addr, len: next->ai_addrlen))
135 goto listen;
136 }
137
138 errstr = "binding socket";
139 goto fail;
140
141 listen:;
142 freeaddrinfo (ai: addrs);
143 addrs = nullptr;
144
145 if (listen (fd: fd, n: backlog ? backlog : 17) < 0)
146 {
147 errstr = "listening socket";
148 goto fail;
149 }
150
151 return fd;
152}
153
154}
155#endif
156

source code of libcody/netserver.cc