libavformat/url.c - manifest_repos/ffmpeg - Git at Google

 /*
  * URL utility functions
  * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */


 #include "avformat.h"
 #include "internal.h"
 #include "config.h"
 #include "url.h"
 #if CONFIG_NETWORK
 #include "network.h"
 #endif
 #include "libavutil/avassert.h"
 #include "libavutil/avstring.h"

 /**
  * @file
  * URL utility functions.
  */

 int ff_url_join(char *str, int size, const char *proto,
                 const char *authorization, const char *hostname,
                 int port, const char *fmt, ...)
 {
 #if CONFIG_NETWORK
     struct addrinfo hints = { 0 }, *ai;
 #endif

     str[0] = '\0';
     if (proto)
         av_strlcatf(str, size, "%s://", proto);
     if (authorization && authorization[0])
         av_strlcatf(str, size, "%s@", authorization);
 #if CONFIG_NETWORK && defined(AF_INET6)
     /* Determine if hostname is a numerical IPv6 address,
      * properly escape it within [] in that case. */
     hints.ai_flags = AI_NUMERICHOST;
     if (!getaddrinfo(hostname, NULL, &hints, &ai)) {
         if (ai->ai_family == AF_INET6) {
             av_strlcat(str, "[", size);
             av_strlcat(str, hostname, size);
             av_strlcat(str, "]", size);
         } else {
             av_strlcat(str, hostname, size);
         }
         freeaddrinfo(ai);
     } else
 #endif
         /* Not an IPv6 address, just output the plain string. */
         av_strlcat(str, hostname, size);

     if (port >= 0)
         av_strlcatf(str, size, ":%d", port);
     if (fmt) {
         va_list vl;
         size_t len = strlen(str);

         va_start(vl, fmt);
         vsnprintf(str + len, size > len ? size - len : 0, fmt, vl);
         va_end(vl);
     }
     return strlen(str);
 }

 static const char *find_delim(const char *delim, const char *cur, const char *end)
 {
     while (cur < end && !strchr(delim, *cur))
         cur++;
     return cur;
 }

 int ff_url_decompose(URLComponents *uc, const char *url, const char *end)
 {
     const char *cur, *aend, *p;

     av_assert0(url);
     if (!end)
         end = url + strlen(url);
     cur = uc->url = url;

     /* scheme */
     uc->scheme = cur;
     p = find_delim(":/?#", cur, end); /* lavf "schemes" can contain options but not some RFC 3986 delimiters */
     if (*p == ':')
         cur = p + 1;

     /* authority */
     uc->authority = cur;
     if (end - cur >= 2 && cur[0] == '/' && cur[1] == '/') {
         cur += 2;
         aend = find_delim("/?#", cur, end);

         /* userinfo */
         uc->userinfo = cur;
         p = find_delim("@", cur, aend);
         if (*p == '@')
             cur = p + 1;

         /* host */
         uc->host = cur;
         if (*cur == '[') { /* hello IPv6, thanks for using colons! */
             p = find_delim("]", cur, aend);
             if (*p != ']')
                 return AVERROR(EINVAL);
             if (p + 1 < aend && p[1] != ':')
                 return AVERROR(EINVAL);
             cur = p + 1;
         } else {
             cur = find_delim(":", cur, aend);
         }

         /* port */
         uc->port = cur;
         cur = aend;
     } else {
         uc->userinfo = uc->host = uc->port = cur;
     }

     /* path */
     uc->path = cur;
     cur = find_delim("?#", cur, end);

     /* query */
     uc->query = cur;
     if (*cur == '?')
         cur = find_delim("#", cur, end);

     /* fragment */
     uc->fragment = cur;

     uc->end = end;
     return 0;
 }

 static int append_path(char *root, char *out_end, char **rout,
                        const char *in, const char *in_end)
 {
     char *out = *rout;
     const char *d, *next;

     if (in < in_end && *in == '/')
         in++; /* already taken care of */
     while (in < in_end) {
         d = find_delim("/", in, in_end);
         next = d + (d < in_end && *d == '/');
         if (d - in == 1 && in[0] == '.') {
             /* skip */
         } else if (d - in == 2 && in[0] == '.' && in[1] == '.') {
             av_assert1(out[-1] == '/');
             if (out - root > 1)
                 while (out > root && (--out)[-1] != '/');
         } else {
             if (out_end - out < next - in)
                 return AVERROR(ENOMEM);
             memmove(out, in, next - in);
             out += next - in;
         }
         in = next;
     }
     *rout = out;
     return 0;
 }

 int ff_make_absolute_url(char *buf, int size, const char *base,
                           const char *rel)
 {
     URLComponents ub, uc;
     char *out, *out_end, *path;
     const char *keep, *base_path_end;
     int use_base_path, simplify_path = 0, ret;

     /* This is tricky.
        For HTTP, http://server/site/page + ../media/file
        should resolve into http://server/media/file
        but for filesystem access, dir/playlist + ../media/file
        should resolve into dir/../media/file
        because dir could be a symlink, and .. points to
        the actual parent of the target directory.

        We'll consider that URLs with an actual scheme and authority,
        i.e. starting with scheme://, need parent dir simplification,
        while bare paths or pseudo-URLs starting with proto: without
        the double slash do not.

        For real URLs, the processing is similar to the algorithm described
        here:
        https://tools.ietf.org/html/rfc3986#section-5
      */

     if (!size)
         return AVERROR(ENOMEM);
     out = buf;
     out_end = buf + size - 1;

     if (!base)
         base = "";
     if ((ret = ff_url_decompose(&ub, base, NULL) < 0) ||
         (ret = ff_url_decompose(&uc, rel,  NULL) < 0))
         goto error;

     keep = ub.url;
 #define KEEP(component, also) do { \
         if (uc.url_component_end_##component == uc.url && \
             ub.url_component_end_##component > keep) { \
             keep = ub.url_component_end_##component; \
             also \
         } \
     } while (0)
     KEEP(scheme, );
     KEEP(authority_full, simplify_path = 1;);
     KEEP(path,);
     KEEP(query,);
     KEEP(fragment,);
 #undef KEEP
 #define COPY(start, end) do { \
         size_t len = end - start; \
         if (len > out_end - out) { \
             ret = AVERROR(ENOMEM);  \
             goto error; \
         } \
         memmove(out, start, len); \
         out += len; \
     } while (0)
     COPY(ub.url, keep);
     COPY(uc.url, uc.path);

     use_base_path = URL_COMPONENT_HAVE(ub, path) && keep <= ub.path;
     if (uc.path > uc.url)
         use_base_path = 0;
     if (URL_COMPONENT_HAVE(uc, path) && uc.path[0] == '/')
         use_base_path = 0;
     if (use_base_path) {
         base_path_end = ub.url_component_end_path;
         if (URL_COMPONENT_HAVE(uc, path))
             while (base_path_end > ub.path && base_path_end[-1] != '/')
                 base_path_end--;
     }
     if (keep > ub.path)
         simplify_path = 0;
     if (URL_COMPONENT_HAVE(uc, scheme))
         simplify_path = 0;
     if (URL_COMPONENT_HAVE(uc, authority))
         simplify_path = 1;
     /* No path at all, leave it */
     if (!use_base_path && !URL_COMPONENT_HAVE(uc, path))
         simplify_path = 0;

     if (simplify_path) {
         const char *root = "/";
         COPY(root, root + 1);
         path = out;
         if (use_base_path) {
             ret = append_path(path, out_end, &out, ub.path, base_path_end);
             if (ret < 0)
                 goto error;
         }
         if (URL_COMPONENT_HAVE(uc, path)) {
             ret = append_path(path, out_end, &out, uc.path, uc.url_component_end_path);
             if (ret < 0)
                 goto error;
         }
     } else {
         if (use_base_path)
             COPY(ub.path, base_path_end);
         COPY(uc.path, uc.url_component_end_path);
     }

     COPY(uc.url_component_end_path, uc.end);
 #undef COPY
     *out = 0;
     return 0;

 error:
     snprintf(buf, size, "invalid:%s",
              ret == AVERROR(ENOMEM) ? "truncated" :
              ret == AVERROR(EINVAL) ? "syntax_error" : "");
     return ret;
 }

 AVIODirEntry *ff_alloc_dir_entry(void)
 {
     AVIODirEntry *entry = av_mallocz(sizeof(AVIODirEntry));
     if (entry) {
         entry->type = AVIO_ENTRY_UNKNOWN;
         entry->size = -1;
         entry->modification_timestamp = -1;
         entry->access_timestamp = -1;
         entry->status_change_timestamp = -1;
         entry->user_id = -1;
         entry->group_id = -1;
         entry->filemode = -1;
     }
     return entry;
 }
	/*
	* URL utility functions
	* Copyright (c) 2000, 2001, 2002 Fabrice Bellard
	*
	* This file is part of FFmpeg.
	*
	* FFmpeg is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Lesser General Public
	* License as published by the Free Software Foundation; either
	* version 2.1 of the License, or (at your option) any later version.
	*
	* FFmpeg is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Lesser General Public License for more details.
	*
	* You should have received a copy of the GNU Lesser General Public
	* License along with FFmpeg; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	*/


	#include "avformat.h"
	#include "internal.h"
	#include "config.h"
	#include "url.h"
	#if CONFIG_NETWORK
	#include "network.h"
	#endif
	#include "libavutil/avassert.h"
	#include "libavutil/avstring.h"

	/**
	* @file
	* URL utility functions.
	*/

	int ff_url_join(char str, int size, const char proto,
	const char authorization, const char hostname,
	int port, const char *fmt, ...)
	{
	#if CONFIG_NETWORK
	struct addrinfo hints = { 0 }, *ai;
	#endif

	str[0] = '\0';
	if (proto)
	av_strlcatf(str, size, "%s://", proto);
	if (authorization && authorization[0])
	av_strlcatf(str, size, "%s@", authorization);
	#if CONFIG_NETWORK && defined(AF_INET6)
	/* Determine if hostname is a numerical IPv6 address,
	* properly escape it within [] in that case. */
	hints.ai_flags = AI_NUMERICHOST;
	if (!getaddrinfo(hostname, NULL, &hints, &ai)) {
	if (ai->ai_family == AF_INET6) {
	av_strlcat(str, "[", size);
	av_strlcat(str, hostname, size);
	av_strlcat(str, "]", size);
	} else {
	av_strlcat(str, hostname, size);
	}
	freeaddrinfo(ai);
	} else
	#endif
	/* Not an IPv6 address, just output the plain string. */
	av_strlcat(str, hostname, size);

	if (port >= 0)
	av_strlcatf(str, size, ":%d", port);
	if (fmt) {
	va_list vl;
	size_t len = strlen(str);

	va_start(vl, fmt);
	vsnprintf(str + len, size > len ? size - len : 0, fmt, vl);
	va_end(vl);
	}
	return strlen(str);
	}

	static const char find_delim(const char delim, const char cur, const char end)
	{
	while (cur < end && !strchr(delim, *cur))
	cur++;
	return cur;
	}

	int ff_url_decompose(URLComponents uc, const char url, const char *end)
	{
	const char cur, aend, *p;

	av_assert0(url);
	if (!end)
	end = url + strlen(url);
	cur = uc->url = url;

	/* scheme */
	uc->scheme = cur;
	p = find_delim(":/?#", cur, end); /* lavf "schemes" can contain options but not some RFC 3986 delimiters */
	if (*p == ':')
	cur = p + 1;

	/* authority */
	uc->authority = cur;
	if (end - cur >= 2 && cur[0] == '/' && cur[1] == '/') {
	cur += 2;
	aend = find_delim("/?#", cur, end);

	/* userinfo */
	uc->userinfo = cur;
	p = find_delim("@", cur, aend);
	if (*p == '@')
	cur = p + 1;

	/* host */
	uc->host = cur;
	if (cur == '[') { / hello IPv6, thanks for using colons! */
	p = find_delim("]", cur, aend);
	if (*p != ']')
	return AVERROR(EINVAL);
	if (p + 1 < aend && p[1] != ':')
	return AVERROR(EINVAL);
	cur = p + 1;
	} else {
	cur = find_delim(":", cur, aend);
	}

	/* port */
	uc->port = cur;
	cur = aend;
	} else {
	uc->userinfo = uc->host = uc->port = cur;
	}

	/* path */
	uc->path = cur;
	cur = find_delim("?#", cur, end);

	/* query */
	uc->query = cur;
	if (*cur == '?')
	cur = find_delim("#", cur, end);

	/* fragment */
	uc->fragment = cur;

	uc->end = end;
	return 0;
	}

	static int append_path(char root, char out_end, char **rout,
	const char in, const char in_end)
	{
	char out = rout;
	const char d, next;

	if (in < in_end && *in == '/')
	in++; /* already taken care of */
	while (in < in_end) {
	d = find_delim("/", in, in_end);
	next = d + (d < in_end && *d == '/');
	if (d - in == 1 && in[0] == '.') {
	/* skip */
	} else if (d - in == 2 && in[0] == '.' && in[1] == '.') {
	av_assert1(out[-1] == '/');
	if (out - root > 1)
	while (out > root && (--out)[-1] != '/');
	} else {
	if (out_end - out < next - in)
	return AVERROR(ENOMEM);
	memmove(out, in, next - in);
	out += next - in;
	}
	in = next;
	}
	*rout = out;
	return 0;
	}

	int ff_make_absolute_url(char buf, int size, const char base,
	const char *rel)
	{
	URLComponents ub, uc;
	char out, out_end, *path;
	const char keep, base_path_end;
	int use_base_path, simplify_path = 0, ret;

	/* This is tricky.
	For HTTP, http://server/site/page + ../media/file
	should resolve into http://server/media/file
	but for filesystem access, dir/playlist + ../media/file
	should resolve into dir/../media/file
	because dir could be a symlink, and .. points to
	the actual parent of the target directory.

	We'll consider that URLs with an actual scheme and authority,
	i.e. starting with scheme://, need parent dir simplification,
	while bare paths or pseudo-URLs starting with proto: without
	the double slash do not.

	For real URLs, the processing is similar to the algorithm described
	here:
	https://tools.ietf.org/html/rfc3986#section-5
	*/

	if (!size)
	return AVERROR(ENOMEM);
	out = buf;
	out_end = buf + size - 1;

	if (!base)
	base = "";
	if ((ret = ff_url_decompose(&ub, base, NULL) < 0) \|\|
	(ret = ff_url_decompose(&uc, rel, NULL) < 0))
	goto error;

	keep = ub.url;
	#define KEEP(component, also) do { \
	if (uc.url_component_end_##component == uc.url && \
	ub.url_component_end_##component > keep) { \
	keep = ub.url_component_end_##component; \
	also \
	} \
	} while (0)
	KEEP(scheme, );
	KEEP(authority_full, simplify_path = 1;);
	KEEP(path,);
	KEEP(query,);
	KEEP(fragment,);
	#undef KEEP
	#define COPY(start, end) do { \
	size_t len = end - start; \
	if (len > out_end - out) { \
	ret = AVERROR(ENOMEM); \
	goto error; \
	} \
	memmove(out, start, len); \
	out += len; \
	} while (0)
	COPY(ub.url, keep);
	COPY(uc.url, uc.path);

	use_base_path = URL_COMPONENT_HAVE(ub, path) && keep <= ub.path;
	if (uc.path > uc.url)
	use_base_path = 0;
	if (URL_COMPONENT_HAVE(uc, path) && uc.path[0] == '/')
	use_base_path = 0;
	if (use_base_path) {
	base_path_end = ub.url_component_end_path;
	if (URL_COMPONENT_HAVE(uc, path))
	while (base_path_end > ub.path && base_path_end[-1] != '/')
	base_path_end--;
	}
	if (keep > ub.path)
	simplify_path = 0;
	if (URL_COMPONENT_HAVE(uc, scheme))
	simplify_path = 0;
	if (URL_COMPONENT_HAVE(uc, authority))
	simplify_path = 1;
	/* No path at all, leave it */
	if (!use_base_path && !URL_COMPONENT_HAVE(uc, path))
	simplify_path = 0;

	if (simplify_path) {
	const char *root = "/";
	COPY(root, root + 1);
	path = out;
	if (use_base_path) {
	ret = append_path(path, out_end, &out, ub.path, base_path_end);
	if (ret < 0)
	goto error;
	}
	if (URL_COMPONENT_HAVE(uc, path)) {
	ret = append_path(path, out_end, &out, uc.path, uc.url_component_end_path);
	if (ret < 0)
	goto error;
	}
	} else {
	if (use_base_path)
	COPY(ub.path, base_path_end);
	COPY(uc.path, uc.url_component_end_path);
	}

	COPY(uc.url_component_end_path, uc.end);
	#undef COPY
	*out = 0;
	return 0;

	error:
	snprintf(buf, size, "invalid:%s",
	ret == AVERROR(ENOMEM) ? "truncated" :
	ret == AVERROR(EINVAL) ? "syntax_error" : "");
	return ret;
	}

	AVIODirEntry *ff_alloc_dir_entry(void)
	{
	AVIODirEntry *entry = av_mallocz(sizeof(AVIODirEntry));
	if (entry) {
	entry->type = AVIO_ENTRY_UNKNOWN;
	entry->size = -1;
	entry->modification_timestamp = -1;
	entry->access_timestamp = -1;
	entry->status_change_timestamp = -1;
	entry->user_id = -1;
	entry->group_id = -1;
	entry->filemode = -1;
	}
	return entry;
	}