The Tor Browser: config/pathsub.c@97036ab72558

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

     1 /* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

     2 /* This Source Code Form is subject to the terms of the Mozilla Public

     3  * License, v. 2.0. If a copy of the MPL was not distributed with this

     4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     5 /*

     6 ** Pathname subroutines.

     7 **

     8 ** Brendan Eich, 8/29/95

     9 */

    10 #include <assert.h>

    11 #include <sys/types.h>

    12 #include <dirent.h>

    13 #include <errno.h>

    14 #include <stdarg.h>

    15 #include <stdio.h>

    16 #include <stdlib.h>

    17 #include <string.h>

    18 #include <unistd.h>

    19 #include <sys/stat.h>

    20 #include "pathsub.h"

    22 #ifdef USE_REENTRANT_LIBC

    23 #include <libc_r.h>

    24 #endif

    26 #ifdef SUNOS4

    27 #include "sunos4.h"

    28 #endif

    30 #ifndef D_INO

    31 #define D_INO	d_ino

    32 #endif

    34 char *program;

    36 void

    37 fail(char *format, ...)

    38 {

    39     int error;

    40     va_list ap;

    42 #ifdef USE_REENTRANT_LIBC

    43     R_STRERROR_INIT_R();

    44 #endif

    46     error = errno;

    47     fprintf(stderr, "%s: ", program);

    48     va_start(ap, format);

    49     vfprintf(stderr, format, ap);

    50     va_end(ap);

    51     if (error) {

    53 #ifdef USE_REENTRANT_LIBC

    54     R_STRERROR_R(errno);

    55 	fprintf(stderr, ": %s", r_strerror_r);

    56 #else

    57 	fprintf(stderr, ": %s", strerror(errno));

    58 #endif

    59     }

    61     putc('\n', stderr);

    62     exit(1);

    63 }

    65 char *

    66 getcomponent(char *path, char *name)

    67 {

    68     if (*path == '\0')

    69 	return 0;

    70     if (*path == '/') {

    71 	*name++ = '/';

    72     } else {

    73 	do {

    74 	    *name++ = *path++;

    75 	} while (*path != '/' && *path != '\0');

    76     }

    77     *name = '\0';

    78     while (*path == '/')

    79 	path++;

    80     return path;

    81 }

    83 #ifdef LAME_READDIR

    84 #include <sys/param.h>

    85 /*

    86 ** The static buffer in Unixware's readdir is too small.

    87 */

    88 struct dirent *readdir(DIR *d)

    89 {

    90         static struct dirent *buf = NULL;

    92         if(buf == NULL)

    93                 buf = (struct dirent *) malloc(sizeof(struct dirent) + MAXPATHLEN);

    94         return(readdir_r(d, buf));

    95 }

    96 #endif

    98 char *

    99 ino2name(ino_t ino)

   100 {

   101     DIR *dp;

   102     struct dirent *ep;

   103     char *name;

   105     dp = opendir("..");

   106     if (!dp)

   107 	fail("cannot read parent directory");

   108     for (;;) {

   109 	if (!(ep = readdir(dp)))

   110 	    fail("cannot find current directory");

   111 	if (ep->D_INO == ino)

   112 	    break;

   113     }

   114     name = xstrdup(ep->d_name);

   115     closedir(dp);

   116     return name;

   117 }

   119 void *

   120 xmalloc(size_t size)

   121 {

   122     void *p = malloc(size);

   123     if (!p)

   124 	fail("cannot allocate %u bytes", size);

   125     return p;

   126 }

   128 char *

   129 xstrdup(char *s)

   130 {

   131     return strcpy(xmalloc(strlen(s) + 1), s);

   132 }

   134 char *

   135 xbasename(char *path)

   136 {

   137     char *cp;

   139     while ((cp = strrchr(path, '/')) && cp[1] == '\0')

   140 	*cp = '\0';

   141     if (!cp) return path;

   142     return cp + 1;

   143 }

   145 void

   146 xchdir(char *dir)

   147 {

   148     if (chdir(dir) < 0)

   149 	fail("cannot change directory to %s", dir);

   150 }

   152 int

   153 relatepaths(char *from, char *to, char *outpath)

   154 {

   155     char *cp, *cp2;

   156     int len;

   157     char buf[NAME_MAX];

   159     assert(*from == '/' && *to == '/');

   160     for (cp = to, cp2 = from; *cp == *cp2; cp++, cp2++)

   161 	if (*cp == '\0')

   162 	    break;

   163     while (cp[-1] != '/')

   164 	cp--, cp2--;

   165     if (cp - 1 == to) {

   166 	/* closest common ancestor is /, so use full pathname */

   167 	len = strlen(strcpy(outpath, to));

   168 	if (outpath[len] != '/') {

   169 	    outpath[len++] = '/';

   170 	    outpath[len] = '\0';

   171 	}

   172     } else {

   173 	len = 0;

   174 	while ((cp2 = getcomponent(cp2, buf)) != 0) {

   175 	    strcpy(outpath + len, "../");

   176 	    len += 3;

   177 	}

   178 	while ((cp = getcomponent(cp, buf)) != 0) {

   179 	    sprintf(outpath + len, "%s/", buf);

   180 	    len += strlen(outpath + len);

   181 	}

   182     }

   183     return len;

   184 }

   186 void

   187 reversepath(char *inpath, char *name, int len, char *outpath)

   188 {

   189     char *cp, *cp2;

   190     char buf[NAME_MAX];

   191     struct stat sb;

   193     cp = strcpy(outpath + PATH_MAX - (len + 1), name);

   194     cp2 = inpath;

   195     while ((cp2 = getcomponent(cp2, buf)) != 0) {

   196 	if (strcmp(buf, ".") == 0)

   197 	    continue;

   198 	if (strcmp(buf, "..") == 0) {

   199 	    if (stat(".", &sb) < 0)

   200 		fail("cannot stat current directory");

   201 	    name = ino2name(sb.st_ino);

   202 	    len = strlen(name);

   203 	    cp -= len + 1;

   204 	    strcpy(cp, name);

   205 	    cp[len] = '/';

   206 	    free(name);

   207 	    xchdir("..");

   208 	} else {

   209 	    cp -= 3;

   210 	    strncpy(cp, "../", 3);

   211 	    xchdir(buf);

   212 	}

   213     }

   214     strcpy(outpath, cp);

   215 }

The Tor Browser / file revision

config/pathsub.c@97036ab72558

config/pathsub.c