Fix: Set loopback adress in set_ip_addr if gethostbyname2 fails
[lttng-tools.git] / src / common / uri.c
1 /*
2 * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License, version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc., 51
15 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18 #define _LGPL_SOURCE
19 #include <assert.h>
20 #include <arpa/inet.h>
21 #include <common/compat/netdb.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <sys/socket.h>
25
26 #include <common/common.h>
27 #include <common/defaults.h>
28 #include <common/utils.h>
29
30 #include "uri.h"
31
32 #define LOOPBACK_ADDR_IPV4 "127.0.0.1"
33 #define LOOPBACK_ADDR_IPV6 "::1"
34
35 enum uri_proto_code {
36 P_NET, P_NET6, P_FILE, P_TCP, P_TCP6,
37 };
38
39 struct uri_proto {
40 const char *name;
41 const char *leading_string;
42 enum uri_proto_code code;
43 enum lttng_proto_type type;
44 enum lttng_dst_type dtype;
45 };
46
47 /* Supported protocols */
48 static const struct uri_proto proto_uri[] = {
49 { .name = "file", .leading_string = "file://", .code = P_FILE, .type = 0, .dtype = LTTNG_DST_PATH },
50 { .name = "net", .leading_string = "net://", .code = P_NET, .type = LTTNG_TCP, .dtype = LTTNG_DST_IPV4 },
51 { .name = "net4", .leading_string = "net4://", .code = P_NET, .type = LTTNG_TCP, .dtype = LTTNG_DST_IPV4 },
52 { .name = "net6", .leading_string = "net6://", .code = P_NET6, .type = LTTNG_TCP, .dtype = LTTNG_DST_IPV6 },
53 { .name = "tcp", .leading_string = "tcp://", .code = P_TCP, .type = LTTNG_TCP, .dtype = LTTNG_DST_IPV4 },
54 { .name = "tcp4", .leading_string = "tcp4://", .code = P_TCP, .type = LTTNG_TCP, .dtype = LTTNG_DST_IPV4 },
55 { .name = "tcp6", .leading_string = "tcp6://", .code = P_TCP6, .type = LTTNG_TCP, .dtype = LTTNG_DST_IPV6 },
56 /* Invalid proto marking the end of the array. */
57 { NULL, NULL, 0, 0, 0 }
58 };
59
60 /*
61 * Return pointer to the character in s matching one of the characters in
62 * accept. If nothing is found, return pointer to the end of string (eos).
63 */
64 static const inline char *strpbrk_or_eos(const char *s, const char *accept)
65 {
66 char *p = strpbrk(s, accept);
67 if (p == NULL) {
68 p = strchr(s, '\0');
69 }
70
71 return p;
72 }
73
74 /*
75 * Validate if proto is a supported protocol from proto_uri array.
76 */
77 static const struct uri_proto *get_uri_proto(const char *uri_str)
78 {
79 const struct uri_proto *supported = NULL;
80
81 /* Safety net */
82 if (uri_str == NULL) {
83 goto end;
84 }
85
86 for (supported = &proto_uri[0];
87 supported->leading_string != NULL; ++supported) {
88 if (strncasecmp(uri_str, supported->leading_string,
89 strlen(supported->leading_string)) == 0) {
90 goto end;
91 }
92 }
93
94 /* Proto not found */
95 return NULL;
96
97 end:
98 return supported;
99 }
100
101 /*
102 * Set network address from string into dst. Supports both IP string and
103 * hostname.
104 */
105 static int set_ip_address(const char *addr, int af, char *dst, size_t size)
106 {
107 int ret;
108 unsigned char buf[sizeof(struct in6_addr)];
109 struct hostent *record;
110
111 assert(addr);
112 assert(dst);
113
114 memset(dst, 0, size);
115
116 /* Network protocol */
117 ret = inet_pton(af, addr, buf);
118 if (ret < 1) {
119 /* We consider the dst to be an hostname or an invalid IP char */
120 record = lttng_gethostbyname2(addr, af);
121 if (record) {
122 /* Translate IP to string */
123 if (!inet_ntop(af, record->h_addr_list[0], dst, size)) {
124 PERROR("inet_ntop");
125 goto error;
126 }
127 } else if (!strcmp(addr, "localhost") &&
128 (af == AF_INET || af == AF_INET6)) {
129 /*
130 * Some systems may not have "localhost" defined in
131 * accordance with IETF RFC 6761. According to this RFC,
132 * applications may recognize "localhost" names as
133 * special and resolve to the appropriate loopback
134 * address.
135 *
136 * We choose to use the system name resolution API first
137 * to honor its network configuration. If this fails, we
138 * resolve to the appropriate loopback address. This is
139 * done to accomodate systems which may want to start
140 * tracing before their network configured.
141 */
142 const char *loopback_addr = af == AF_INET ?
143 LOOPBACK_ADDR_IPV4 : LOOPBACK_ADDR_IPV6;
144 const size_t loopback_addr_len = af == AF_INET ?
145 sizeof(LOOPBACK_ADDR_IPV4) :
146 sizeof(LOOPBACK_ADDR_IPV6);
147
148 DBG2("Could not resolve localhost address, using fallback");
149 if (loopback_addr_len > size) {
150 ERR("Could not resolve localhost address; destination string is too short");
151 goto error;
152 }
153 strcpy(dst, loopback_addr);
154 } else {
155 /* At this point, the IP or the hostname is bad */
156 goto error;
157 }
158 } else {
159 if (size > 0) {
160 strncpy(dst, addr, size);
161 dst[size - 1] = '\0';
162 }
163 }
164
165 DBG2("IP address resolved to %s", dst);
166 return 0;
167
168 error:
169 ERR("URI parse bad hostname %s for af %d", addr, af);
170 return -1;
171 }
172
173 /*
174 * Set default URI attribute which is basically the given stream type and the
175 * default port if none is set in the URI.
176 */
177 static void set_default_uri_attr(struct lttng_uri *uri,
178 enum lttng_stream_type stype)
179 {
180 uri->stype = stype;
181 if (uri->dtype != LTTNG_DST_PATH && uri->port == 0) {
182 uri->port = (stype == LTTNG_STREAM_CONTROL) ?
183 DEFAULT_NETWORK_CONTROL_PORT : DEFAULT_NETWORK_DATA_PORT;
184 }
185 }
186
187 /*
188 * Compare two URL destination.
189 *
190 * Return 0 is equal else is not equal.
191 */
192 static int compare_destination(struct lttng_uri *ctrl, struct lttng_uri *data)
193 {
194 int ret;
195
196 assert(ctrl);
197 assert(data);
198
199 switch (ctrl->dtype) {
200 case LTTNG_DST_IPV4:
201 ret = strncmp(ctrl->dst.ipv4, data->dst.ipv4, sizeof(ctrl->dst.ipv4));
202 break;
203 case LTTNG_DST_IPV6:
204 ret = strncmp(ctrl->dst.ipv6, data->dst.ipv6, sizeof(ctrl->dst.ipv6));
205 break;
206 default:
207 ret = -1;
208 break;
209 }
210
211 return ret;
212 }
213
214 /*
215 * Build a string URL from a lttng_uri object.
216 */
217 LTTNG_HIDDEN
218 int uri_to_str_url(struct lttng_uri *uri, char *dst, size_t size)
219 {
220 int ipver, ret;
221 const char *addr;
222 char proto[5], port[7];
223
224 assert(uri);
225 assert(dst);
226
227 if (uri->dtype == LTTNG_DST_PATH) {
228 ipver = 0;
229 addr = uri->dst.path;
230 (void) snprintf(proto, sizeof(proto), "file");
231 (void) snprintf(port, sizeof(port), "%s", "");
232 } else {
233 ipver = (uri->dtype == LTTNG_DST_IPV4) ? 4 : 6;
234 addr = (ipver == 4) ? uri->dst.ipv4 : uri->dst.ipv6;
235 (void) snprintf(proto, sizeof(proto), "tcp%d", ipver);
236 (void) snprintf(port, sizeof(port), ":%d", uri->port);
237 }
238
239 ret = snprintf(dst, size, "%s://%s%s%s%s/%s", proto,
240 (ipver == 6) ? "[" : "", addr, (ipver == 6) ? "]" : "",
241 port, uri->subdir);
242 if (ret < 0) {
243 PERROR("snprintf uri to url");
244 }
245
246 return ret;
247 }
248
249 /*
250 * Compare two URIs.
251 *
252 * Return 0 if equal else 1.
253 */
254 LTTNG_HIDDEN
255 int uri_compare(struct lttng_uri *uri1, struct lttng_uri *uri2)
256 {
257 return memcmp(uri1, uri2, sizeof(struct lttng_uri));
258 }
259
260 /*
261 * Free URI memory.
262 */
263 LTTNG_HIDDEN
264 void uri_free(struct lttng_uri *uri)
265 {
266 free(uri);
267 }
268
269 /*
270 * Return an allocated URI.
271 */
272 LTTNG_HIDDEN
273 struct lttng_uri *uri_create(void)
274 {
275 struct lttng_uri *uri;
276
277 uri = zmalloc(sizeof(struct lttng_uri));
278 if (uri == NULL) {
279 PERROR("zmalloc uri");
280 }
281
282 return uri;
283 }
284
285 /*
286 * Parses a string URI to a lttng_uri. This function can potentially return
287 * more than one URI in uris so the size of the array is returned and uris is
288 * allocated and populated. Caller must free(3) the array.
289 *
290 * This function can not detect the stream type of the URI so the caller has to
291 * make sure the correct type (stype) is set on the return URI(s). The default
292 * port must also be set by the caller if the returned URI has its port set to
293 * zero.
294 *
295 * NOTE: A good part of the following code was inspired from the "wget" source
296 * tree from the src/url.c file and url_parse() function. Also, the
297 * strpbrk_or_eos() function found above is also inspired by the same code.
298 * This code was originally licensed GPLv2 so we acknolwedge the Free Software
299 * Foundation here for the work and to make sure we are compliant with it.
300 */
301 LTTNG_HIDDEN
302 ssize_t uri_parse(const char *str_uri, struct lttng_uri **uris)
303 {
304 int ret, i = 0;
305 /* Size of the uris array. Default is 1 */
306 ssize_t size = 1;
307 char subdir[PATH_MAX];
308 unsigned int ctrl_port = 0;
309 unsigned int data_port = 0;
310 struct lttng_uri *tmp_uris;
311 char *addr_f = NULL;
312 const struct uri_proto *proto;
313 const char *purl, *addr_e, *addr_b, *subdir_b = NULL;
314 const char *seps = ":/\0";
315
316 /*
317 * The first part is the protocol portion of a maximum of 5 bytes for now.
318 * The second part is the hostname or IP address. The 255 bytes size is the
319 * limit found in the RFC 1035 for the total length of a domain name
320 * (https://www.ietf.org/rfc/rfc1035.txt). Finally, for the net://
321 * protocol, two ports CAN be specified.
322 */
323
324 DBG3("URI string: %s", str_uri);
325
326 proto = get_uri_proto(str_uri);
327 if (proto == NULL) {
328 ERR("URI parse unknown protocol %s", str_uri);
329 goto error;
330 }
331
332 purl = str_uri;
333
334 if (proto->code == P_NET || proto->code == P_NET6) {
335 /* Special case for net:// which requires two URI objects */
336 size = 2;
337 }
338
339 /* Allocate URI array */
340 tmp_uris = zmalloc(sizeof(struct lttng_uri) * size);
341 if (tmp_uris == NULL) {
342 PERROR("zmalloc uri");
343 goto error;
344 }
345
346 memset(subdir, 0, sizeof(subdir));
347 purl += strlen(proto->leading_string);
348
349 /* Copy known value to the first URI. */
350 tmp_uris[0].dtype = proto->dtype;
351 tmp_uris[0].proto = proto->type;
352
353 if (proto->code == P_FILE) {
354 if (*purl != '/') {
355 ERR("Missing destination full path.");
356 goto free_error;
357 }
358
359 strncpy(tmp_uris[0].dst.path, purl, sizeof(tmp_uris[0].dst.path));
360 tmp_uris[0].dst.path[sizeof(tmp_uris[0].dst.path) - 1] = '\0';
361 DBG3("URI file destination: %s", purl);
362 goto end;
363 }
364
365 /* Assume we are at the beginning of an address or host of some sort. */
366 addr_b = purl;
367
368 /*
369 * Handle IPv6 address inside square brackets as mention by RFC 2732. IPv6
370 * address that does not start AND end with brackets will be rejected even
371 * if valid.
372 *
373 * proto://[<addr>]...
374 * ^
375 */
376 if (*purl == '[') {
377 /* Address begins after '[' */
378 addr_b = purl + 1;
379 addr_e = strchr(addr_b, ']');
380 if (addr_e == NULL || addr_b == addr_e) {
381 ERR("Broken IPv6 address %s", addr_b);
382 goto free_error;
383 }
384
385 /* Moving parsed URL pointer after the final bracket ']' */
386 purl = addr_e + 1;
387
388 /*
389 * The closing bracket must be followed by a seperator or NULL char.
390 */
391 if (strchr(seps, *purl) == NULL) {
392 ERR("Unknown symbol after IPv6 address: %s", purl);
393 goto free_error;
394 }
395 } else {
396 purl = strpbrk_or_eos(purl, seps);
397 addr_e = purl;
398 }
399
400 /* Check if we at least have a char for the addr or hostname. */
401 if (addr_b == addr_e) {
402 ERR("No address or hostname detected.");
403 goto free_error;
404 }
405
406 addr_f = utils_strdupdelim(addr_b, addr_e);
407 if (addr_f == NULL) {
408 goto free_error;
409 }
410
411 /*
412 * Detect PORT after address. The net/net6 protocol allows up to two port
413 * so we can define the control and data port.
414 */
415 while (*purl == ':') {
416 const char *port_b, *port_e;
417 char *port_f;
418
419 /* Update pass counter */
420 i++;
421
422 /*
423 * Maximum of two ports is possible if P_NET/NET6. Bigger than that,
424 * two much stuff.
425 */
426 if ((i == 2 && (proto->code != P_NET && proto->code != P_NET6))
427 || i > 2) {
428 break;
429 }
430
431 /*
432 * Move parsed URL to port value.
433 * proto://addr_host:PORT1:PORT2/foo/bar
434 * ^
435 */
436 ++purl;
437 port_b = purl;
438 purl = strpbrk_or_eos(purl, seps);
439 port_e = purl;
440
441 if (port_b != port_e) {
442 int port;
443
444 port_f = utils_strdupdelim(port_b, port_e);
445 if (port_f == NULL) {
446 goto free_error;
447 }
448
449 port = atoi(port_f);
450 if (port > 0xffff || port <= 0x0) {
451 ERR("Invalid port number %d", port);
452 free(port_f);
453 goto free_error;
454 }
455 free(port_f);
456
457 if (i == 1) {
458 ctrl_port = port;
459 } else {
460 data_port = port;
461 }
462 }
463 };
464
465 /* Check for a valid subdir or trailing garbage */
466 if (*purl == '/') {
467 /*
468 * Move to subdir value.
469 * proto://addr_host:PORT1:PORT2/foo/bar
470 * ^
471 */
472 ++purl;
473 subdir_b = purl;
474 } else if (*purl != '\0') {
475 ERR("Trailing characters not recognized: %s", purl);
476 goto free_error;
477 }
478
479 /* We have enough valid information to create URI(s) object */
480
481 /* Copy generic information */
482 tmp_uris[0].port = ctrl_port;
483
484 /* Copy subdirectory if one. */
485 if (subdir_b) {
486 strncpy(tmp_uris[0].subdir, subdir_b, sizeof(tmp_uris[0].subdir));
487 tmp_uris[0].subdir[sizeof(tmp_uris[0].subdir) - 1] = '\0';
488 }
489
490 switch (proto->code) {
491 case P_NET:
492 ret = set_ip_address(addr_f, AF_INET, tmp_uris[0].dst.ipv4,
493 sizeof(tmp_uris[0].dst.ipv4));
494 if (ret < 0) {
495 goto free_error;
496 }
497
498 memcpy(tmp_uris[1].dst.ipv4, tmp_uris[0].dst.ipv4, sizeof(tmp_uris[1].dst.ipv4));
499
500 tmp_uris[1].dtype = proto->dtype;
501 tmp_uris[1].proto = proto->type;
502 tmp_uris[1].port = data_port;
503 break;
504 case P_NET6:
505 ret = set_ip_address(addr_f, AF_INET6, tmp_uris[0].dst.ipv6,
506 sizeof(tmp_uris[0].dst.ipv6));
507 if (ret < 0) {
508 goto free_error;
509 }
510
511 memcpy(tmp_uris[1].dst.ipv6, tmp_uris[0].dst.ipv6, sizeof(tmp_uris[1].dst.ipv6));
512
513 tmp_uris[1].dtype = proto->dtype;
514 tmp_uris[1].proto = proto->type;
515 tmp_uris[1].port = data_port;
516 break;
517 case P_TCP:
518 ret = set_ip_address(addr_f, AF_INET, tmp_uris[0].dst.ipv4,
519 sizeof(tmp_uris[0].dst.ipv4));
520 if (ret < 0) {
521 goto free_error;
522 }
523 break;
524 case P_TCP6:
525 ret = set_ip_address(addr_f, AF_INET6, tmp_uris[0].dst.ipv6,
526 sizeof(tmp_uris[0].dst.ipv6));
527 if (ret < 0) {
528 goto free_error;
529 }
530 break;
531 default:
532 goto free_error;
533 }
534
535 end:
536 DBG3("URI dtype: %d, proto: %d, host: %s, subdir: %s, ctrl: %d, data: %d",
537 proto->dtype, proto->type, (addr_f == NULL) ? "" : addr_f,
538 (subdir_b == NULL) ? "" : subdir_b, ctrl_port, data_port);
539
540 free(addr_f);
541
542 *uris = tmp_uris;
543 return size;
544
545 free_error:
546 free(addr_f);
547 free(tmp_uris);
548 error:
549 return -1;
550 }
551
552 /*
553 * Parse a string URL and creates URI(s) returning the size of the populated
554 * array.
555 */
556 LTTNG_HIDDEN
557 ssize_t uri_parse_str_urls(const char *ctrl_url, const char *data_url,
558 struct lttng_uri **uris)
559 {
560 unsigned int equal = 1, idx = 0;
561 /* Add the "file://" size to the URL maximum size */
562 char url[PATH_MAX + 7];
563 ssize_t size_ctrl = 0, size_data = 0, size;
564 struct lttng_uri *ctrl_uris = NULL, *data_uris = NULL;
565 struct lttng_uri *tmp_uris = NULL;
566
567 /* No URL(s) is allowed. This means that the consumer will be disabled. */
568 if (ctrl_url == NULL && data_url == NULL) {
569 return 0;
570 }
571
572 /* Check if URLs are equal and if so, only use the control URL */
573 if ((ctrl_url && *ctrl_url != '\0') && (data_url && *data_url != '\0')) {
574 equal = !strcmp(ctrl_url, data_url);
575 }
576
577 /*
578 * Since we allow the str_url to be a full local filesystem path, we are
579 * going to create a valid file:// URL if it's the case.
580 *
581 * Check if first character is a '/' or else reject the URL.
582 */
583 if (ctrl_url && ctrl_url[0] == '/') {
584 int ret;
585
586 ret = snprintf(url, sizeof(url), "file://%s", ctrl_url);
587 if (ret < 0) {
588 PERROR("snprintf file url");
589 goto parse_error;
590 }
591 ctrl_url = url;
592 }
593
594 /* Parse the control URL if there is one */
595 if (ctrl_url && *ctrl_url != '\0') {
596 size_ctrl = uri_parse(ctrl_url, &ctrl_uris);
597 if (size_ctrl < 1) {
598 ERR("Unable to parse the URL %s", ctrl_url);
599 goto parse_error;
600 }
601
602 /* At this point, we know there is at least one URI in the array */
603 set_default_uri_attr(&ctrl_uris[0], LTTNG_STREAM_CONTROL);
604
605 if (ctrl_uris[0].dtype == LTTNG_DST_PATH &&
606 (data_url && *data_url != '\0')) {
607 ERR("Can not have a data URL when destination is file://");
608 goto error;
609 }
610
611 /* URL are not equal but the control URL uses a net:// protocol */
612 if (size_ctrl == 2) {
613 if (!equal) {
614 ERR("Control URL uses the net:// protocol and the data URL is "
615 "different. Not allowed.");
616 goto error;
617 } else {
618 set_default_uri_attr(&ctrl_uris[1], LTTNG_STREAM_DATA);
619 /*
620 * The data_url and ctrl_url are equal and the ctrl_url
621 * contains a net:// protocol so we just skip the data part.
622 */
623 data_url = NULL;
624 }
625 }
626 }
627
628 if (data_url && *data_url != '\0') {
629 int ret;
630
631 /* We have to parse the data URL in this case */
632 size_data = uri_parse(data_url, &data_uris);
633 if (size_data < 1) {
634 ERR("Unable to parse the URL %s", data_url);
635 goto error;
636 } else if (size_data == 2) {
637 ERR("Data URL can not be set with the net[4|6]:// protocol");
638 goto error;
639 }
640
641 set_default_uri_attr(&data_uris[0], LTTNG_STREAM_DATA);
642
643 ret = compare_destination(&ctrl_uris[0], &data_uris[0]);
644 if (ret != 0) {
645 ERR("Control and data destination mismatch");
646 goto error;
647 }
648 }
649
650 /* Compute total size */
651 size = size_ctrl + size_data;
652
653 tmp_uris = zmalloc(sizeof(struct lttng_uri) * size);
654 if (tmp_uris == NULL) {
655 PERROR("zmalloc uris");
656 goto error;
657 }
658
659 if (ctrl_uris) {
660 /* It's possible the control URIs array contains more than one URI */
661 memcpy(tmp_uris, ctrl_uris, sizeof(struct lttng_uri) * size_ctrl);
662 ++idx;
663 free(ctrl_uris);
664 }
665
666 if (data_uris) {
667 memcpy(&tmp_uris[idx], data_uris, sizeof(struct lttng_uri));
668 free(data_uris);
669 }
670
671 *uris = tmp_uris;
672
673 return size;
674
675 error:
676 free(ctrl_uris);
677 free(data_uris);
678 free(tmp_uris);
679 parse_error:
680 return -1;
681 }
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