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Add many comments to server/play.c, in advance of possible
[disorder] / lib / addr.c
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460b9539 1/*
2 * This file is part of DisOrder.
5aff007d 3 * Copyright (C) 2004, 2007, 2008 Richard Kettlewell
460b9539 4 *
e7eb3a27 5 * This program is free software: you can redistribute it and/or modify
460b9539 6 * it under the terms of the GNU General Public License as published by
e7eb3a27 7 * the Free Software Foundation, either version 3 of the License, or
460b9539 8 * (at your option) any later version.
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9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
460b9539 15 * You should have received a copy of the GNU General Public License
e7eb3a27 16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
460b9539 17 */
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18/** @file lib/addr.c
19 * @brief Socket address support */
460b9539 20
05b75f8d 21#include "common.h"
460b9539 22
460b9539 23#include <sys/types.h>
24#include <sys/socket.h>
25#include <netinet/in.h>
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26#include <arpa/inet.h>
27#include <sys/un.h>
460b9539 28
29#include "log.h"
30#include "printf.h"
460b9539 31#include "addr.h"
6fba990c 32#include "mem.h"
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33#include "syscalls.h"
34#include "configuration.h"
35#include "vector.h"
460b9539 36
ec6f8488 37/** @brief Convert a pair of strings to an address
38 * @param a Pointer to string list
39 * @param pref Hints structure for getaddrinfo, or NULL
40 * @param namep Where to store address description, or NULL
41 * @return Address info structure or NULL on error
42 *
43 * This converts one or two strings into an address specification suitable
44 * for passing to socket(), bind() etc.
45 *
46 * If there is only one string then it is assumed to be the service
47 * name (port number). If there are two then the first is the host
48 * name and the second the service name.
49 *
50 * @p namep is used to return a description of the address suitable
51 * for use in log messages.
52 *
53 * If an error occurs a message is logged and a null pointer returned.
54 */
460b9539 55struct addrinfo *get_address(const struct stringlist *a,
56 const struct addrinfo *pref,
57 char **namep) {
58 struct addrinfo *res;
59 char *name;
60 int rc;
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61
62 switch(a->n) {
63 case 1:
460b9539 64 byte_xasprintf(&name, "host * service %s", a->s[0]);
65 if((rc = getaddrinfo(0, a->s[0], pref, &res))) {
66 error(0, "getaddrinfo %s: %s", a->s[0], gai_strerror(rc));
67 return 0;
68 }
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69 break;
70 case 2:
460b9539 71 byte_xasprintf(&name, "host %s service %s", a->s[0], a->s[1]);
72 if((rc = getaddrinfo(a->s[0], a->s[1], pref, &res))) {
73 error(0, "getaddrinfo %s %s: %s", a->s[0], a->s[1], gai_strerror(rc));
74 return 0;
75 }
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76 break;
77 default:
78 error(0, "invalid network address specification (n=%d)", a->n);
79 return 0;
460b9539 80 }
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81 if(!res || (pref && res->ai_socktype != pref->ai_socktype)) {
82 error(0, "getaddrinfo didn't give us a suitable socket address");
460b9539 83 if(res)
84 freeaddrinfo(res);
85 return 0;
86 }
87 if(namep)
88 *namep = name;
89 return res;
90}
91
d7b6f0d1 92/** @brief Comparison function for address information
93 *
94 * Suitable for qsort().
95 */
460b9539 96int addrinfocmp(const struct addrinfo *a,
97 const struct addrinfo *b) {
460b9539 98 if(a->ai_family != b->ai_family) return a->ai_family - b->ai_family;
99 if(a->ai_socktype != b->ai_socktype) return a->ai_socktype - b->ai_socktype;
100 if(a->ai_protocol != b->ai_protocol) return a->ai_protocol - b->ai_protocol;
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101 return sockaddrcmp(a->ai_addr, b->ai_addr);
102}
103
104/** @brief Comparison function for socket addresses
105 *
106 * Suitable for qsort().
107 */
108int sockaddrcmp(const struct sockaddr *a,
109 const struct sockaddr *b) {
110 const struct sockaddr_in *ina, *inb;
111 const struct sockaddr_in6 *in6a, *in6b;
112
113 if(a->sa_family != b->sa_family) return a->sa_family - b->sa_family;
114 switch(a->sa_family) {
460b9539 115 case PF_INET:
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116 ina = (const struct sockaddr_in *)a;
117 inb = (const struct sockaddr_in *)b;
460b9539 118 if(ina->sin_port != inb->sin_port) return ina->sin_port - inb->sin_port;
119 return ina->sin_addr.s_addr - inb->sin_addr.s_addr;
120 break;
121 case PF_INET6:
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122 in6a = (const struct sockaddr_in6 *)a;
123 in6b = (const struct sockaddr_in6 *)b;
460b9539 124 if(in6a->sin6_port != in6b->sin6_port)
125 return in6a->sin6_port - in6b->sin6_port;
126 return memcmp(&in6a->sin6_addr, &in6b->sin6_addr,
127 sizeof (struct in6_addr));
128 default:
80dc2c5f 129 fatal(0, "unsupported protocol family %d", a->sa_family);
460b9539 130 }
131}
6fba990c 132
0590cedc 133/** @brief Return nonzero if @p sin4 is an IPv4 multicast address */
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134static inline int multicast4(const struct sockaddr_in *sin4) {
135 return IN_MULTICAST(ntohl(sin4->sin_addr.s_addr));
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136}
137
0590cedc 138/** @brief Return nonzero if @p sin6 is an IPv6 multicast address */
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139static inline int multicast6(const struct sockaddr_in6 *sin6) {
140 return IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr);
141}
142
143/** @brief Return true if @p sa represents a multicast address */
144int multicast(const struct sockaddr *sa) {
145 switch(sa->sa_family) {
146 case AF_INET:
147 return multicast4((const struct sockaddr_in *)sa);
148 case AF_INET6:
149 return multicast6((const struct sockaddr_in6 *)sa);
150 default:
151 return 0;
152 }
153}
154
0590cedc 155/** @brief Format an IPv4 address */
8d516888 156static inline char *format_sockaddr4(const struct sockaddr_in *sin4) {
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157 char buffer[1024], *r;
158
8d516888 159 if(sin4->sin_port)
6fba990c 160 byte_xasprintf(&r, "%s port %u",
8d516888 161 inet_ntop(sin4->sin_family, &sin4->sin_addr,
6fba990c 162 buffer, sizeof buffer),
8d516888 163 ntohs(sin4->sin_port));
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164 else
165 byte_xasprintf(&r, "%s",
8d516888 166 inet_ntop(sin4->sin_family, &sin4->sin_addr,
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167 buffer, sizeof buffer));
168 return r;
169}
170
0590cedc 171/** @brief Format an IPv6 address */
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172static inline char *format_sockaddr6(const struct sockaddr_in6 *sin6) {
173 char buffer[1024], *r;
174
175 if(sin6->sin6_port)
176 byte_xasprintf(&r, "%s port %u",
177 inet_ntop(sin6->sin6_family, &sin6->sin6_addr,
178 buffer, sizeof buffer),
179 ntohs(sin6->sin6_port));
180 else
181 byte_xasprintf(&r, "%s",
182 inet_ntop(sin6->sin6_family, &sin6->sin6_addr,
183 buffer, sizeof buffer));
184 return r;
185}
186
0590cedc 187/** @brief Format a UNIX socket address */
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188static inline char *format_sockaddrun(const struct sockaddr_un *sun) {
189 return xstrdup(sun->sun_path);
190}
191
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192/** @brief Construct a text description a sockaddr
193 * @param sa Socket address
194 * @return Human-readable form of address
195 */
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196char *format_sockaddr(const struct sockaddr *sa) {
197 switch(sa->sa_family) {
198 case AF_INET:
199 return format_sockaddr4((const struct sockaddr_in *)sa);
200 case AF_INET6:
201 return format_sockaddr6((const struct sockaddr_in6 *)sa);
202 case AF_UNIX:
203 return format_sockaddrun((const struct sockaddr_un *)sa);
204 default:
205 return 0;
206 }
207}
208
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209/** @brief Parse the text form of a network address
210 * @param na Where to store result
211 * @param nvec Number of strings
212 * @param vec List of strings
213 * @return 0 on success, -1 on syntax error
214 */
215int netaddress_parse(struct netaddress *na,
216 int nvec,
217 char **vec) {
218 const char *port;
219
220 na->af = AF_UNSPEC;
221 if(nvec > 0 && vec[0][0] == '-') {
222 if(!strcmp(vec[0], "-4"))
223 na->af = AF_INET;
224 else if(!strcmp(vec[0], "-6"))
225 na->af = AF_INET6;
226 else if(!strcmp(vec[0], "-unix"))
227 na->af = AF_UNIX;
228 else if(!strcmp(vec[0], "-"))
229 na->af = AF_UNSPEC;
230 else
231 return -1;
232 --nvec;
233 ++vec;
234 }
235 if(nvec == 0)
236 return -1;
237 /* Possibilities are:
238 *
239 * /path/to/unix/socket an AF_UNIX socket
240 * * PORT any address, specific port
241 * PORT any address, specific port
242 * ADDRESS PORT specific address, specific port
243 */
244 if(vec[0][0] == '/' && na->af == AF_UNSPEC)
245 na->af = AF_UNIX;
246 if(na->af == AF_UNIX) {
247 if(nvec != 1)
248 return -1;
249 na->address = xstrdup(vec[0]);
250 na->port = -1; /* makes no sense */
251 } else {
252 switch(nvec) {
253 case 1:
254 na->address = NULL;
255 port = vec[0];
256 break;
257 case 2:
258 if(!strcmp(vec[0], "*"))
259 na->address = NULL;
260 else
261 na->address = xstrdup(vec[0]);
262 port = vec[1];
263 break;
264 default:
265 return -1;
266 }
267 if(port[strspn(port, "0123456789")])
268 return -1;
269 long p;
270 int e = xstrtol(&p, port, NULL, 10);
271
272 if(e)
273 return -1;
274 if(p > 65535)
275 return -1;
276 na->port = (int)p;
277 }
278 return 0;
279}
280
281/** @brief Format a @ref netaddress structure
282 * @param na Network address to format
283 * @param nvecp Where to put string count, or NULL
284 * @param vecp Where to put strings
285 *
286 * The formatted form is suitable for passing to netaddress_parse().
287 */
288void netaddress_format(const struct netaddress *na,
289 int *nvecp,
290 char ***vecp) {
291 struct vector v[1];
292
293 vector_init(v);
294 switch(na->af) {
295 case AF_UNSPEC: vector_append(v, xstrdup("-")); break;
296 case AF_INET: vector_append(v, xstrdup("-4")); break;
297 case AF_INET6: vector_append(v, xstrdup("-6")); break;
298 case AF_UNIX: vector_append(v, xstrdup("-unix")); break;
299 }
300 if(na->address)
301 vector_append(v, xstrdup(na->address));
302 else
303 vector_append(v, xstrdup("*"));
304 if(na->port != -1) {
305 char buffer[64];
306
307 snprintf(buffer, sizeof buffer, "%d", na->port);
308 vector_append(v, xstrdup(buffer));
309 }
310 vector_terminate(v);
311 if(nvecp)
312 *nvecp = v->nvec;
313 if(vecp)
314 *vecp = v->vec;
315}
316
317/** @brief Resolve a network address
318 * @param na Address structure
319 * @param passive True if passive (bindable) address is desired
320 * @param protocol Protocol number desired (e.g. @c IPPROTO_TCP)
321 * @return List of suitable addresses or NULL
322 */
323struct addrinfo *netaddress_resolve(const struct netaddress *na,
324 int passive,
325 int protocol) {
326 struct addrinfo *res, hints[1];
327 char service[64];
328 int rc;
329
330 memset(hints, 0, sizeof hints);
331 hints->ai_family = na->af;
332 hints->ai_protocol = protocol;
333 hints->ai_flags = passive ? AI_PASSIVE : 0;
334 snprintf(service, sizeof service, "%d", na->port);
335 rc = getaddrinfo(na->address, service, hints, &res);
336 if(rc) {
337 error(0, "getaddrinfo %s %d: %s",
338 na->address ? na->address : "*",
339 na->port, gai_strerror(rc));
340 return NULL;
341 }
342 return res;
343}
344
460b9539 345/*
346Local Variables:
347c-basic-offset:2
348comment-column:40
349End:
350*/