Contents of /tags/mkinitrd-6_2_3/busybox/libbb/xconnect.c
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Mon May 31 20:54:44 2010 UTC (14 years, 3 months ago) by niro
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File size: 12667 byte(s)
Mon May 31 20:54:44 2010 UTC (14 years, 3 months ago) by niro
File MIME type: text/plain
File size: 12667 byte(s)
tagged 'mkinitrd-6_2_3'
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * Utility routines. |
4 | * |
5 | * Connect to host at port using address resolution from getaddrinfo |
6 | * |
7 | * Licensed under GPLv2, see file LICENSE in this tarball for details. |
8 | */ |
9 | |
10 | #include <sys/socket.h> /* netinet/in.h needs it */ |
11 | #include <netinet/in.h> |
12 | #include <net/if.h> |
13 | #include <sys/un.h> |
14 | #include "libbb.h" |
15 | |
16 | void FAST_FUNC setsockopt_reuseaddr(int fd) |
17 | { |
18 | setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &const_int_1, sizeof(const_int_1)); |
19 | } |
20 | int FAST_FUNC setsockopt_broadcast(int fd) |
21 | { |
22 | return setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &const_int_1, sizeof(const_int_1)); |
23 | } |
24 | int FAST_FUNC setsockopt_bindtodevice(int fd, const char *iface) |
25 | { |
26 | int r; |
27 | struct ifreq ifr; |
28 | strncpy_IFNAMSIZ(ifr.ifr_name, iface); |
29 | /* NB: passing (iface, strlen(iface) + 1) does not work! |
30 | * (maybe it works on _some_ kernels, but not on 2.6.26) |
31 | * Actually, ifr_name is at offset 0, and in practice |
32 | * just giving char[IFNAMSIZ] instead of struct ifreq works too. |
33 | * But just in case it's not true on some obscure arch... */ |
34 | r = setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr)); |
35 | if (r) |
36 | bb_perror_msg("can't bind to interface %s", iface); |
37 | return r; |
38 | } |
39 | |
40 | len_and_sockaddr* FAST_FUNC get_sock_lsa(int fd) |
41 | { |
42 | len_and_sockaddr lsa; |
43 | len_and_sockaddr *lsa_ptr; |
44 | |
45 | lsa.len = LSA_SIZEOF_SA; |
46 | if (getsockname(fd, &lsa.u.sa, &lsa.len) != 0) |
47 | return NULL; |
48 | |
49 | lsa_ptr = xzalloc(LSA_LEN_SIZE + lsa.len); |
50 | if (lsa.len > LSA_SIZEOF_SA) { /* rarely (if ever) happens */ |
51 | lsa_ptr->len = lsa.len; |
52 | getsockname(fd, &lsa_ptr->u.sa, &lsa_ptr->len); |
53 | } else { |
54 | memcpy(lsa_ptr, &lsa, LSA_LEN_SIZE + lsa.len); |
55 | } |
56 | return lsa_ptr; |
57 | } |
58 | |
59 | void FAST_FUNC xconnect(int s, const struct sockaddr *s_addr, socklen_t addrlen) |
60 | { |
61 | if (connect(s, s_addr, addrlen) < 0) { |
62 | if (ENABLE_FEATURE_CLEAN_UP) |
63 | close(s); |
64 | if (s_addr->sa_family == AF_INET) |
65 | bb_perror_msg_and_die("%s (%s)", |
66 | "can't connect to remote host", |
67 | inet_ntoa(((struct sockaddr_in *)s_addr)->sin_addr)); |
68 | bb_perror_msg_and_die("can't connect to remote host"); |
69 | } |
70 | } |
71 | |
72 | /* Return port number for a service. |
73 | * If "port" is a number use it as the port. |
74 | * If "port" is a name it is looked up in /etc/services, |
75 | * if it isnt found return default_port |
76 | */ |
77 | unsigned FAST_FUNC bb_lookup_port(const char *port, const char *protocol, unsigned default_port) |
78 | { |
79 | unsigned port_nr = default_port; |
80 | if (port) { |
81 | int old_errno; |
82 | |
83 | /* Since this is a lib function, we're not allowed to reset errno to 0. |
84 | * Doing so could break an app that is deferring checking of errno. */ |
85 | old_errno = errno; |
86 | port_nr = bb_strtou(port, NULL, 10); |
87 | if (errno || port_nr > 65535) { |
88 | struct servent *tserv = getservbyname(port, protocol); |
89 | port_nr = default_port; |
90 | if (tserv) |
91 | port_nr = ntohs(tserv->s_port); |
92 | } |
93 | errno = old_errno; |
94 | } |
95 | return (uint16_t)port_nr; |
96 | } |
97 | |
98 | |
99 | /* "Old" networking API - only IPv4 */ |
100 | |
101 | /* |
102 | void FAST_FUNC bb_lookup_host(struct sockaddr_in *s_in, const char *host) |
103 | { |
104 | struct hostent *he; |
105 | |
106 | memset(s_in, 0, sizeof(struct sockaddr_in)); |
107 | s_in->sin_family = AF_INET; |
108 | he = xgethostbyname(host); |
109 | memcpy(&(s_in->sin_addr), he->h_addr_list[0], he->h_length); |
110 | } |
111 | |
112 | |
113 | int FAST_FUNC xconnect_tcp_v4(struct sockaddr_in *s_addr) |
114 | { |
115 | int s = xsocket(AF_INET, SOCK_STREAM, 0); |
116 | xconnect(s, (struct sockaddr*) s_addr, sizeof(*s_addr)); |
117 | return s; |
118 | } |
119 | */ |
120 | |
121 | /* "New" networking API */ |
122 | |
123 | |
124 | int FAST_FUNC get_nport(const struct sockaddr *sa) |
125 | { |
126 | #if ENABLE_FEATURE_IPV6 |
127 | if (sa->sa_family == AF_INET6) { |
128 | return ((struct sockaddr_in6*)sa)->sin6_port; |
129 | } |
130 | #endif |
131 | if (sa->sa_family == AF_INET) { |
132 | return ((struct sockaddr_in*)sa)->sin_port; |
133 | } |
134 | /* What? UNIX socket? IPX?? :) */ |
135 | return -1; |
136 | } |
137 | |
138 | void FAST_FUNC set_nport(len_and_sockaddr *lsa, unsigned port) |
139 | { |
140 | #if ENABLE_FEATURE_IPV6 |
141 | if (lsa->u.sa.sa_family == AF_INET6) { |
142 | lsa->u.sin6.sin6_port = port; |
143 | return; |
144 | } |
145 | #endif |
146 | if (lsa->u.sa.sa_family == AF_INET) { |
147 | lsa->u.sin.sin_port = port; |
148 | return; |
149 | } |
150 | /* What? UNIX socket? IPX?? :) */ |
151 | } |
152 | |
153 | /* We hijack this constant to mean something else */ |
154 | /* It doesn't hurt because we will remove this bit anyway */ |
155 | #define DIE_ON_ERROR AI_CANONNAME |
156 | |
157 | /* host: "1.2.3.4[:port]", "www.google.com[:port]" |
158 | * port: if neither of above specifies port # */ |
159 | static len_and_sockaddr* str2sockaddr( |
160 | const char *host, int port, |
161 | IF_FEATURE_IPV6(sa_family_t af,) |
162 | int ai_flags) |
163 | { |
164 | IF_NOT_FEATURE_IPV6(sa_family_t af = AF_INET;) |
165 | int rc; |
166 | len_and_sockaddr *r; |
167 | struct addrinfo *result = NULL; |
168 | struct addrinfo *used_res; |
169 | const char *org_host = host; /* only for error msg */ |
170 | const char *cp; |
171 | struct addrinfo hint; |
172 | |
173 | if (ENABLE_FEATURE_UNIX_LOCAL && strncmp(host, "local:", 6) == 0) { |
174 | struct sockaddr_un *sun; |
175 | |
176 | r = xzalloc(LSA_LEN_SIZE + sizeof(struct sockaddr_un)); |
177 | r->len = sizeof(struct sockaddr_un); |
178 | r->u.sa.sa_family = AF_UNIX; |
179 | sun = (struct sockaddr_un *)&r->u.sa; |
180 | safe_strncpy(sun->sun_path, host + 6, sizeof(sun->sun_path)); |
181 | return r; |
182 | } |
183 | |
184 | r = NULL; |
185 | |
186 | /* Ugly parsing of host:addr */ |
187 | if (ENABLE_FEATURE_IPV6 && host[0] == '[') { |
188 | /* Even uglier parsing of [xx]:nn */ |
189 | host++; |
190 | cp = strchr(host, ']'); |
191 | if (!cp || (cp[1] != ':' && cp[1] != '\0')) { |
192 | /* Malformed: must be [xx]:nn or [xx] */ |
193 | bb_error_msg("bad address '%s'", org_host); |
194 | if (ai_flags & DIE_ON_ERROR) |
195 | xfunc_die(); |
196 | return NULL; |
197 | } |
198 | } else { |
199 | cp = strrchr(host, ':'); |
200 | if (ENABLE_FEATURE_IPV6 && cp && strchr(host, ':') != cp) { |
201 | /* There is more than one ':' (e.g. "::1") */ |
202 | cp = NULL; /* it's not a port spec */ |
203 | } |
204 | } |
205 | if (cp) { /* points to ":" or "]:" */ |
206 | int sz = cp - host + 1; |
207 | |
208 | host = safe_strncpy(alloca(sz), host, sz); |
209 | if (ENABLE_FEATURE_IPV6 && *cp != ':') { |
210 | cp++; /* skip ']' */ |
211 | if (*cp == '\0') /* [xx] without port */ |
212 | goto skip; |
213 | } |
214 | cp++; /* skip ':' */ |
215 | port = bb_strtou(cp, NULL, 10); |
216 | if (errno || (unsigned)port > 0xffff) { |
217 | bb_error_msg("bad port spec '%s'", org_host); |
218 | if (ai_flags & DIE_ON_ERROR) |
219 | xfunc_die(); |
220 | return NULL; |
221 | } |
222 | skip: ; |
223 | } |
224 | |
225 | /* Next two if blocks allow to skip getaddrinfo() |
226 | * in case host name is a numeric IP(v6) address. |
227 | * getaddrinfo() initializes DNS resolution machinery, |
228 | * scans network config and such - tens of syscalls. |
229 | */ |
230 | /* If we were not asked specifically for IPv6, |
231 | * check whether this is a numeric IPv4 */ |
232 | IF_FEATURE_IPV6(if(af != AF_INET6)) { |
233 | struct in_addr in4; |
234 | if (inet_aton(host, &in4) != 0) { |
235 | r = xzalloc(LSA_LEN_SIZE + sizeof(struct sockaddr_in)); |
236 | r->len = sizeof(struct sockaddr_in); |
237 | r->u.sa.sa_family = AF_INET; |
238 | r->u.sin.sin_addr = in4; |
239 | goto set_port; |
240 | } |
241 | } |
242 | #if ENABLE_FEATURE_IPV6 |
243 | /* If we were not asked specifically for IPv4, |
244 | * check whether this is a numeric IPv6 */ |
245 | if (af != AF_INET) { |
246 | struct in6_addr in6; |
247 | if (inet_pton(AF_INET6, host, &in6) > 0) { |
248 | r = xzalloc(LSA_LEN_SIZE + sizeof(struct sockaddr_in6)); |
249 | r->len = sizeof(struct sockaddr_in6); |
250 | r->u.sa.sa_family = AF_INET6; |
251 | r->u.sin6.sin6_addr = in6; |
252 | goto set_port; |
253 | } |
254 | } |
255 | #endif |
256 | |
257 | memset(&hint, 0 , sizeof(hint)); |
258 | hint.ai_family = af; |
259 | /* Needed. Or else we will get each address thrice (or more) |
260 | * for each possible socket type (tcp,udp,raw...): */ |
261 | hint.ai_socktype = SOCK_STREAM; |
262 | hint.ai_flags = ai_flags & ~DIE_ON_ERROR; |
263 | rc = getaddrinfo(host, NULL, &hint, &result); |
264 | if (rc || !result) { |
265 | bb_error_msg("bad address '%s'", org_host); |
266 | if (ai_flags & DIE_ON_ERROR) |
267 | xfunc_die(); |
268 | goto ret; |
269 | } |
270 | used_res = result; |
271 | #if ENABLE_FEATURE_PREFER_IPV4_ADDRESS |
272 | while (1) { |
273 | if (used_res->ai_family == AF_INET) |
274 | break; |
275 | used_res = used_res->ai_next; |
276 | if (!used_res) { |
277 | used_res = result; |
278 | break; |
279 | } |
280 | } |
281 | #endif |
282 | r = xmalloc(LSA_LEN_SIZE + used_res->ai_addrlen); |
283 | r->len = used_res->ai_addrlen; |
284 | memcpy(&r->u.sa, used_res->ai_addr, used_res->ai_addrlen); |
285 | |
286 | set_port: |
287 | set_nport(r, htons(port)); |
288 | ret: |
289 | freeaddrinfo(result); |
290 | return r; |
291 | } |
292 | #if !ENABLE_FEATURE_IPV6 |
293 | #define str2sockaddr(host, port, af, ai_flags) str2sockaddr(host, port, ai_flags) |
294 | #endif |
295 | |
296 | #if ENABLE_FEATURE_IPV6 |
297 | len_and_sockaddr* FAST_FUNC host_and_af2sockaddr(const char *host, int port, sa_family_t af) |
298 | { |
299 | return str2sockaddr(host, port, af, 0); |
300 | } |
301 | |
302 | len_and_sockaddr* FAST_FUNC xhost_and_af2sockaddr(const char *host, int port, sa_family_t af) |
303 | { |
304 | return str2sockaddr(host, port, af, DIE_ON_ERROR); |
305 | } |
306 | #endif |
307 | |
308 | len_and_sockaddr* FAST_FUNC host2sockaddr(const char *host, int port) |
309 | { |
310 | return str2sockaddr(host, port, AF_UNSPEC, 0); |
311 | } |
312 | |
313 | len_and_sockaddr* FAST_FUNC xhost2sockaddr(const char *host, int port) |
314 | { |
315 | return str2sockaddr(host, port, AF_UNSPEC, DIE_ON_ERROR); |
316 | } |
317 | |
318 | len_and_sockaddr* FAST_FUNC xdotted2sockaddr(const char *host, int port) |
319 | { |
320 | return str2sockaddr(host, port, AF_UNSPEC, AI_NUMERICHOST | DIE_ON_ERROR); |
321 | } |
322 | |
323 | #undef xsocket_type |
324 | int FAST_FUNC xsocket_type(len_and_sockaddr **lsap, IF_FEATURE_IPV6(int family,) int sock_type) |
325 | { |
326 | IF_NOT_FEATURE_IPV6(enum { family = AF_INET };) |
327 | len_and_sockaddr *lsa; |
328 | int fd; |
329 | int len; |
330 | |
331 | #if ENABLE_FEATURE_IPV6 |
332 | if (family == AF_UNSPEC) { |
333 | fd = socket(AF_INET6, sock_type, 0); |
334 | if (fd >= 0) { |
335 | family = AF_INET6; |
336 | goto done; |
337 | } |
338 | family = AF_INET; |
339 | } |
340 | #endif |
341 | fd = xsocket(family, sock_type, 0); |
342 | len = sizeof(struct sockaddr_in); |
343 | #if ENABLE_FEATURE_IPV6 |
344 | if (family == AF_INET6) { |
345 | done: |
346 | len = sizeof(struct sockaddr_in6); |
347 | } |
348 | #endif |
349 | lsa = xzalloc(LSA_LEN_SIZE + len); |
350 | lsa->len = len; |
351 | lsa->u.sa.sa_family = family; |
352 | *lsap = lsa; |
353 | return fd; |
354 | } |
355 | |
356 | int FAST_FUNC xsocket_stream(len_and_sockaddr **lsap) |
357 | { |
358 | return xsocket_type(lsap, IF_FEATURE_IPV6(AF_UNSPEC,) SOCK_STREAM); |
359 | } |
360 | |
361 | static int create_and_bind_or_die(const char *bindaddr, int port, int sock_type) |
362 | { |
363 | int fd; |
364 | len_and_sockaddr *lsa; |
365 | |
366 | if (bindaddr && bindaddr[0]) { |
367 | lsa = xdotted2sockaddr(bindaddr, port); |
368 | /* user specified bind addr dictates family */ |
369 | fd = xsocket(lsa->u.sa.sa_family, sock_type, 0); |
370 | } else { |
371 | fd = xsocket_type(&lsa, IF_FEATURE_IPV6(AF_UNSPEC,) sock_type); |
372 | set_nport(lsa, htons(port)); |
373 | } |
374 | setsockopt_reuseaddr(fd); |
375 | xbind(fd, &lsa->u.sa, lsa->len); |
376 | free(lsa); |
377 | return fd; |
378 | } |
379 | |
380 | int FAST_FUNC create_and_bind_stream_or_die(const char *bindaddr, int port) |
381 | { |
382 | return create_and_bind_or_die(bindaddr, port, SOCK_STREAM); |
383 | } |
384 | |
385 | int FAST_FUNC create_and_bind_dgram_or_die(const char *bindaddr, int port) |
386 | { |
387 | return create_and_bind_or_die(bindaddr, port, SOCK_DGRAM); |
388 | } |
389 | |
390 | |
391 | int FAST_FUNC create_and_connect_stream_or_die(const char *peer, int port) |
392 | { |
393 | int fd; |
394 | len_and_sockaddr *lsa; |
395 | |
396 | lsa = xhost2sockaddr(peer, port); |
397 | fd = xsocket(lsa->u.sa.sa_family, SOCK_STREAM, 0); |
398 | setsockopt_reuseaddr(fd); |
399 | xconnect(fd, &lsa->u.sa, lsa->len); |
400 | free(lsa); |
401 | return fd; |
402 | } |
403 | |
404 | int FAST_FUNC xconnect_stream(const len_and_sockaddr *lsa) |
405 | { |
406 | int fd = xsocket(lsa->u.sa.sa_family, SOCK_STREAM, 0); |
407 | xconnect(fd, &lsa->u.sa, lsa->len); |
408 | return fd; |
409 | } |
410 | |
411 | /* We hijack this constant to mean something else */ |
412 | /* It doesn't hurt because we will add this bit anyway */ |
413 | #define IGNORE_PORT NI_NUMERICSERV |
414 | static char* FAST_FUNC sockaddr2str(const struct sockaddr *sa, int flags) |
415 | { |
416 | char host[128]; |
417 | char serv[16]; |
418 | int rc; |
419 | socklen_t salen; |
420 | |
421 | if (ENABLE_FEATURE_UNIX_LOCAL && sa->sa_family == AF_UNIX) { |
422 | struct sockaddr_un *sun = (struct sockaddr_un *)sa; |
423 | return xasprintf("local:%.*s", |
424 | (int) sizeof(sun->sun_path), |
425 | sun->sun_path); |
426 | } |
427 | |
428 | salen = LSA_SIZEOF_SA; |
429 | #if ENABLE_FEATURE_IPV6 |
430 | if (sa->sa_family == AF_INET) |
431 | salen = sizeof(struct sockaddr_in); |
432 | if (sa->sa_family == AF_INET6) |
433 | salen = sizeof(struct sockaddr_in6); |
434 | #endif |
435 | rc = getnameinfo(sa, salen, |
436 | host, sizeof(host), |
437 | /* can do ((flags & IGNORE_PORT) ? NULL : serv) but why bother? */ |
438 | serv, sizeof(serv), |
439 | /* do not resolve port# into service _name_ */ |
440 | flags | NI_NUMERICSERV |
441 | ); |
442 | if (rc) |
443 | return NULL; |
444 | if (flags & IGNORE_PORT) |
445 | return xstrdup(host); |
446 | #if ENABLE_FEATURE_IPV6 |
447 | if (sa->sa_family == AF_INET6) { |
448 | if (strchr(host, ':')) /* heh, it's not a resolved hostname */ |
449 | return xasprintf("[%s]:%s", host, serv); |
450 | /*return xasprintf("%s:%s", host, serv);*/ |
451 | /* - fall through instead */ |
452 | } |
453 | #endif |
454 | /* For now we don't support anything else, so it has to be INET */ |
455 | /*if (sa->sa_family == AF_INET)*/ |
456 | return xasprintf("%s:%s", host, serv); |
457 | /*return xstrdup(host);*/ |
458 | } |
459 | |
460 | char* FAST_FUNC xmalloc_sockaddr2host(const struct sockaddr *sa) |
461 | { |
462 | return sockaddr2str(sa, 0); |
463 | } |
464 | |
465 | char* FAST_FUNC xmalloc_sockaddr2host_noport(const struct sockaddr *sa) |
466 | { |
467 | return sockaddr2str(sa, IGNORE_PORT); |
468 | } |
469 | |
470 | char* FAST_FUNC xmalloc_sockaddr2hostonly_noport(const struct sockaddr *sa) |
471 | { |
472 | return sockaddr2str(sa, NI_NAMEREQD | IGNORE_PORT); |
473 | } |
474 | char* FAST_FUNC xmalloc_sockaddr2dotted(const struct sockaddr *sa) |
475 | { |
476 | return sockaddr2str(sa, NI_NUMERICHOST); |
477 | } |
478 | |
479 | char* FAST_FUNC xmalloc_sockaddr2dotted_noport(const struct sockaddr *sa) |
480 | { |
481 | return sockaddr2str(sa, NI_NUMERICHOST | IGNORE_PORT); |
482 | } |