The Tor Browser: config/nsinstall.c@97036ab72558 (annotated)

config/nsinstall.c@97036ab72558 (annotated)

config/nsinstall.c

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

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.

 /* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 /*
 ** Netscape portable install command.
 **
 ** Brendan Eich, 7/20/95
 */
 #include <stdio.h>  /* OSF/1 requires this before grp.h, so put it first */
 #include <assert.h>
 #include <fcntl.h>
 #include <errno.h>
 #include <dirent.h>
 #include <limits.h>
 #include <grp.h>
 #include <pwd.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 #include <utime.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include "pathsub.h"
 #ifdef HAVE_GETOPT_H
 #include <getopt.h>
 #endif
 #ifdef SUNOS4
 #include "sunos4.h"
 #endif
 #ifdef NEXTSTEP
 #include <bsd/libc.h>
 #endif
 #ifdef __QNX__
 #include <unix.h>
 #endif
 #ifdef NEED_S_ISLNK
 #if !defined(S_ISLNK) && defined(S_IFLNK)
 #define S_ISLNK(a)	(((a) & S_IFMT) == S_IFLNK)
 #endif
 #endif
 #ifndef _DIRECTORY_SEPARATOR
 #define _DIRECTORY_SEPARATOR "/"
 #endif /* _DIRECTORY_SEPARATOR */
 #ifdef NEED_FCHMOD_PROTO
 extern int fchmod(int fildes, mode_t mode);
 #endif
 static void
 usage(void)
 {
     fprintf(stderr,
 	"usage: %s [-C cwd] [-L linkprefix] [-m mode] [-o owner] [-g group]\n"
 	"       %*s [-DdltR] file [file ...] directory\n",
 	program, (int) strlen(program), "");
     exit(2);
 }
 static int
 mkdirs(char *path, mode_t mode)
 {
     char *cp;
     struct stat sb;
     int res;
     int l;
     /* strip trailing "/." */
     l = strlen(path);
     if(l > 1 && path[l - 1] == '.' && path[l - 2] == '/')
         path[l - 2] = 0;
     while (*path == '/' && path[1] == '/')
 	path++;
     for (cp = strrchr(path, '/'); cp && cp != path && *(cp - 1) == '/'; cp--);
     if (cp && cp != path) {
 	*cp = '\0';
 	if ((lstat(path, &sb) < 0 || !S_ISDIR(sb.st_mode)) &&
 	    mkdirs(path, mode) < 0) {
 	    return -1;
 	}
 	*cp = '/';
     }
     res = mkdir(path, mode);
     if ((res != 0) && (errno == EEXIST))
       return 0;
     else
       return res;
 }
 static uid_t
 touid(char *owner)
 {
     struct passwd *pw;
     uid_t uid;
     char *cp;
     pw = getpwnam(owner);
     if (pw)
 	return pw->pw_uid;
     uid = strtol(owner, &cp, 0);
     if (uid == 0 && cp == owner)
 	fail("cannot find uid for %s", owner);
     return uid;
 }
 static gid_t
 togid(char *group)
 {
     struct group *gr;
     gid_t gid;
     char *cp;
     gr = getgrnam(group);
     if (gr)
 	return gr->gr_gid;
     gid = strtol(group, &cp, 0);
     if (gid == 0 && cp == group)
 	fail("cannot find gid for %s", group);
     return gid;
 }
 static void
 copyfile( char *name, char *toname, mode_t mode, char *group, char *owner,
           int dotimes, uid_t uid, gid_t gid )
 {
   int fromfd, tofd = -1, cc, wc, exists;
   char buf[BUFSIZ], *bp;
   struct stat sb, tosb;
   struct utimbuf utb;
   exists = (lstat(toname, &tosb) == 0);
   fromfd = open(name, O_RDONLY);
   if (fromfd < 0 || fstat(fromfd, &sb) < 0)
     fail("cannot access %s", name);
   if (exists) {
     if (S_ISREG(tosb.st_mode)) {
       /* See if we can open it. This is more reliable than 'access'. */
       tofd = open(toname, O_CREAT | O_WRONLY, 0666);
     }
     if (tofd < 0) {
       (void) (S_ISDIR(tosb.st_mode) ? rmdir : unlink)(toname);
     }
   }
   if (tofd < 0) {
     tofd = open(toname, O_CREAT | O_WRONLY, 0666);
     if (tofd < 0)
       fail("cannot create %s", toname);
   }
   bp = buf;
   while ((cc = read(fromfd, bp, sizeof buf)) > 0)
   {
     while ((wc = write(tofd, bp, (unsigned int)cc)) > 0)
     {
       if ((cc -= wc) == 0)
         break;
       bp += wc;
     }
     if (wc < 0)
       fail("cannot write to %s", toname);
   }
   if (cc < 0)
     fail("cannot read from %s", name);
   if (ftruncate(tofd, sb.st_size) < 0)
     fail("cannot truncate %s", toname);
 #if !defined(VMS)
   if (dotimes)
   {
     utb.actime = sb.st_atime;
     utb.modtime = sb.st_mtime;
     if (utime(toname, &utb) < 0)
       fail("cannot set times of %s", toname);
   }
 #ifdef HAVE_FCHMOD
   if (fchmod(tofd, mode) < 0)
 #else
   if (chmod(toname, mode) < 0)
 #endif
     fail("cannot change mode of %s", toname);
 #endif
   if ((owner || group) && fchown(tofd, uid, gid) < 0)
     fail("cannot change owner of %s", toname);
   /* Must check for delayed (NFS) write errors on close. */
   if (close(tofd) < 0)
     fail("cannot write to %s", toname);
   close(fromfd);
 #if defined(VMS)
   if (chmod(toname, (mode & (S_IREAD | S_IWRITE))) < 0)
     fail("cannot change mode of %s", toname);
   if (dotimes)
   {
     utb.actime = sb.st_atime;
     utb.modtime = sb.st_mtime;
     if (utime(toname, &utb) < 0)
       fail("cannot set times of %s", toname);
   }
 #endif
 }
 static void
 copydir( char *from, char *to, mode_t mode, char *group, char *owner,
          int dotimes, uid_t uid, gid_t gid)
 {
   int i;
   DIR *dir;
   struct dirent *ep;
   struct stat sb;
   char *base, *destdir, *direntry, *destentry;
   base = xbasename(from);
   /* create destination directory */
   destdir = xmalloc((unsigned int)(strlen(to) + 1 + strlen(base) + 1));
   sprintf(destdir, "%s%s%s", to, _DIRECTORY_SEPARATOR, base);
   if (mkdirs(destdir, mode) != 0) {
     fail("cannot make directory %s\n", destdir);
     free(destdir);
     return;
   }
   if (!(dir = opendir(from))) {
     fail("cannot open directory %s\n", from);
     free(destdir);
     return;
   }
   direntry = xmalloc((unsigned int)PATH_MAX);
   destentry = xmalloc((unsigned int)PATH_MAX);
   while ((ep = readdir(dir)))
   {
     if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0)
       continue;
     sprintf(direntry, "%s/%s", from, ep->d_name);
     sprintf(destentry, "%s%s%s", destdir, _DIRECTORY_SEPARATOR, ep->d_name);
     if (stat(direntry, &sb) == 0 && S_ISDIR(sb.st_mode))
       copydir( direntry, destdir, mode, group, owner, dotimes, uid, gid );
     else
       copyfile( direntry, destentry, mode, group, owner, dotimes, uid, gid );
   }
   free(destdir);
   free(direntry);
   free(destentry);
   closedir(dir);
 }
 int
 main(int argc, char **argv)
 {
     int onlydir, dodir, dolink, dorelsymlink, dotimes, opt, len, lplen, tdlen, bnlen, exists, fromfd, tofd, cc, wc;
     mode_t mode = 0755;
     char *linkprefix, *owner, *group, *cp, *cwd, *todir, *toname, *name, *base, *linkname, *bp, buf[BUFSIZ];
     uid_t uid;
     gid_t gid;
     struct stat sb, tosb, fromsb;
     struct utimbuf utb;
     program = argv[0];
     cwd = linkname = linkprefix = owner = group = 0;
     onlydir = dodir = dolink = dorelsymlink = dotimes = lplen = 0;
     while ((opt = getopt(argc, argv, "C:DdlL:Rm:o:g:t")) != EOF) {
 	switch (opt) {
 	  case 'C':
 	    cwd = optarg;
 	    break;
 	  case 'D':
 	    onlydir = 1;
 	    break;
 	  case 'd':
 	    dodir = 1;
 	    break;
 	  case 'L':
 	    linkprefix = optarg;
 	    lplen = strlen(linkprefix);
 	    dolink = 1;
 	    break;
 	  case 'R':
 	    dolink = dorelsymlink = 1;
 	    break;
 	  case 'm':
 	    mode = strtoul(optarg, &cp, 8);
 	    if (mode == 0 && cp == optarg)
 		usage();
 	    break;
 	  case 'o':
 	    owner = optarg;
 	    break;
 	  case 'g':
 	    group = optarg;
 	    break;
 	  case 't':
 	    dotimes = 1;
 	    break;
 	  default:
 	    usage();
 	}
     }
     argc -= optind;
     argv += optind;
     if (argc < 2 - onlydir)
 	usage();
     todir = argv[argc-1];
     if ((stat(todir, &sb) < 0 || !S_ISDIR(sb.st_mode)) &&
 	mkdirs(todir, 0777) < 0) {
 	fail("cannot make directory %s", todir);
     }
     if (onlydir)
 	return 0;
     if (!cwd) {
 #ifndef NEEDS_GETCWD
 #ifndef GETCWD_CANT_MALLOC
 	cwd = getcwd(0, PATH_MAX);
 #else
 	cwd = malloc(PATH_MAX + 1);
 	cwd = getcwd(cwd, PATH_MAX);
 #endif
 #else
 	cwd = malloc(PATH_MAX + 1);
 	cwd = getwd(cwd);
 #endif
     }
     xchdir(todir);
 #ifndef NEEDS_GETCWD
 #ifndef GETCWD_CANT_MALLOC
     todir = getcwd(0, PATH_MAX);
 #else
     todir = malloc(PATH_MAX + 1);
     todir = getcwd(todir, PATH_MAX);
 #endif
 #else
     todir = malloc(PATH_MAX + 1);
     todir = getwd(todir);
 #endif
     tdlen = strlen(todir);
     xchdir(cwd);
     tdlen = strlen(todir);
     uid = owner ? touid(owner) : (uid_t)(-1);
     gid = group ? togid(group) : (gid_t)(-1);
     while (--argc > 0) {
 	name = *argv++;
 	len = strlen(name);
 	base = xbasename(name);
 	bnlen = strlen(base);
 	toname = xmalloc((unsigned int)(tdlen + 1 + bnlen + 1));
 	sprintf(toname, "%s%s%s", todir, _DIRECTORY_SEPARATOR, base);
 	exists = (lstat(toname, &tosb) == 0);
 	if (dodir) {
 	    /* -d means create a directory, always */
 	    if (exists && !S_ISDIR(tosb.st_mode)) {
 		(void) unlink(toname);
 		exists = 0;
 	    }
 	    if (!exists && mkdir(toname, mode) < 0)
 		fail("cannot make directory %s", toname);
 	    if ((owner || group) && chown(toname, uid, gid) < 0)
 		fail("cannot change owner of %s", toname);
 	} else if (dolink) {
             if (access(name, R_OK) != 0) {
                 fail("cannot access %s", name);
             }
 	    if (*name == '/') {
 		/* source is absolute pathname, link to it directly */
 		linkname = 0;
 	    } else {
 		if (linkprefix) {
 		    /* -L prefixes names with a $cwd arg. */
 		    len += lplen + 1;
 		    linkname = xmalloc((unsigned int)(len + 1));
 		    sprintf(linkname, "%s/%s", linkprefix, name);
 		} else if (dorelsymlink) {
 		    /* Symlink the relative path from todir to source name. */
 		    linkname = xmalloc(PATH_MAX);
 		    if (*todir == '/') {
 			/* todir is absolute: skip over common prefix. */
 			lplen = relatepaths(todir, cwd, linkname);
 			strcpy(linkname + lplen, name);
 		    } else {
 			/* todir is named by a relative path: reverse it. */
 			reversepath(todir, name, len, linkname);
 			xchdir(cwd);
 		    }
 		    len = strlen(linkname);
 		}
 		name = linkname;
 	    }
 	    /* Check for a pre-existing symlink with identical content. */
 	    if ((exists && (!S_ISLNK(tosb.st_mode) ||
 						readlink(toname, buf, sizeof buf) != len ||
 						strncmp(buf, name, (unsigned int)len) != 0)) ||
 			((stat(name, &fromsb) == 0) &&
 			 (fromsb.st_mtime > tosb.st_mtime))) {
 		(void) (S_ISDIR(tosb.st_mode) ? rmdir : unlink)(toname);
 		exists = 0;
 	    }
 	    if (!exists && symlink(name, toname) < 0)
 		fail("cannot make symbolic link %s", toname);
 #ifdef HAVE_LCHOWN
 	    if ((owner || group) && lchown(toname, uid, gid) < 0)
 		fail("cannot change owner of %s", toname);
 #endif
 	    if (linkname) {
 		free(linkname);
 		linkname = 0;
 	    }
 	} else {
 	    /* Copy from name to toname, which might be the same file. */
       if( stat(name, &sb) == 0 && S_IFDIR & sb.st_mode )
       {
         /* then is directory: must explicitly create destination dir  */
         /*  and manually copy files over                              */
         copydir( name, todir, mode, group, owner, dotimes, uid, gid );
       }
       else
       {
         copyfile(name, toname, mode, group, owner, dotimes, uid, gid);
       }
     }
 	free(toname);
     }
     free(cwd);
     free(todir);
     return 0;
 }

The Tor Browser / annotate

config/nsinstall.c@97036ab72558 (annotated)

config/nsinstall.c