config/pathsub.c
author Petru Lingurar <petru.lingurar@softvision.ro>
Fri, 21 Dec 2018 08:56:47 +0000
changeset 501492 65621d0fe1262af0643cec37c23b2d9ec42588ad
parent 450439 bb8056c405856f8ec9459956cd01428891a5b407
child 508163 6f3709b3878117466168c40affa7bca0b60cf75b
permissions -rw-r--r--
Bug 1513938 - Enforce a Bundle size limit and drop `privateSession` if exceeds it. r=JanH, a=jcristau The `privateSession` key would normally allow persisting the Private Browsing session across OOMs in Activity's Bundle. We need to do that to avoid storing private, sensible data on disk like we do with the normal browsing session. In some cases `privateSession` would contain a lot of data which, along with other possible concurrent transactions could overflow Binder's buffer which has a limited fixed size, currently 1Mb. To avoid this, we will drop `privateSession` from the Bundle if the resulting size is greater than a _speculative_ size of 300KBs which would mean that in the case of an OOM all Private Browsing state would be lost. Bug 1515592 is filed to investigate for a better solution. Differential Revision: https://phabricator.services.mozilla.com/D15067

/* -*- 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/. */
/*
** Pathname subroutines.
**
** Brendan Eich, 8/29/95
*/
#include <assert.h>
#include <sys/types.h>
#include <dirent.h>
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include "pathsub.h"

#ifdef USE_REENTRANT_LIBC
#include <libc_r.h>
#endif

#ifdef SUNOS4
#include "sunos4.h"
#endif

char *program;

void
fail(const char *format, ...)
{
    int error;
    va_list ap;

#ifdef USE_REENTRANT_LIBC
    R_STRERROR_INIT_R();
#endif

    error = errno;
    fprintf(stderr, "%s: ", program);
    va_start(ap, format);
    vfprintf(stderr, format, ap);
    va_end(ap);
    if (error) {

#ifdef USE_REENTRANT_LIBC
    R_STRERROR_R(errno);
	fprintf(stderr, ": %s", r_strerror_r);
#else
	fprintf(stderr, ": %s", strerror(errno));
#endif
    }

    putc('\n', stderr);
    exit(1);
}

char *
getcomponent(char *path, char *name)
{
    if (*path == '\0')
	return 0;
    if (*path == '/') {
	*name++ = '/';
    } else {
	do {
	    *name++ = *path++;
	} while (*path != '/' && *path != '\0');
    }
    *name = '\0';
    while (*path == '/')
	path++;
    return path;
}

#ifdef LAME_READDIR
#include <sys/param.h>
/*
** The static buffer in Unixware's readdir is too small.
*/
struct dirent *readdir(DIR *d)
{
        static struct dirent *buf = NULL;

        if(buf == NULL)
                buf = (struct dirent *) malloc(sizeof(struct dirent) + MAXPATHLEN);
        return(readdir_r(d, buf));
}
#endif

char *
ino2name(ino_t ino)
{
    DIR *dp;
    struct dirent *ep;
    char *name;

    dp = opendir("..");
    if (!dp)
	fail("cannot read parent directory");
    for (;;) {
	if (!(ep = readdir(dp)))
	    fail("cannot find current directory");
	if (ep->d_ino == ino)
	    break;
    }
    name = xstrdup(ep->d_name);
    closedir(dp);
    return name;
}

void *
xmalloc(size_t size)
{
    void *p = malloc(size);
    if (!p)
	fail("cannot allocate %u bytes", size);
    return p;
}

char *
xstrdup(char *s)
{
    return strcpy(xmalloc(strlen(s) + 1), s);
}

char *
xbasename(char *path)
{
    char *cp;

    while ((cp = strrchr(path, '/')) && cp[1] == '\0')
	*cp = '\0';
    if (!cp) return path;
    return cp + 1;
}

void
xchdir(const char *dir)
{
    if (chdir(dir) < 0)
	fail("cannot change directory to %s", dir);
}

int
relatepaths(char *from, char *to, char *outpath)
{
    char *cp, *cp2;
    int len;
    char buf[NAME_MAX];

    assert(*from == '/' && *to == '/');
    for (cp = to, cp2 = from; *cp == *cp2; cp++, cp2++)
	if (*cp == '\0')
	    break;
    while (cp[-1] != '/')
	cp--, cp2--;
    if (cp - 1 == to) {
	/* closest common ancestor is /, so use full pathname */
	len = strlen(strcpy(outpath, to));
	if (outpath[len] != '/') {
	    outpath[len++] = '/';
	    outpath[len] = '\0';
	}
    } else {
	len = 0;
	while ((cp2 = getcomponent(cp2, buf)) != 0) {
	    strcpy(outpath + len, "../");
	    len += 3;
	}
	while ((cp = getcomponent(cp, buf)) != 0) {
	    sprintf(outpath + len, "%s/", buf);
	    len += strlen(outpath + len);
	}
    }
    return len;
}

void
reversepath(char *inpath, char *name, int len, char *outpath)
{
    char *cp, *cp2;
    char buf[NAME_MAX];
    struct stat sb;

    cp = strcpy(outpath + PATH_MAX - (len + 1), name);
    cp2 = inpath;
    while ((cp2 = getcomponent(cp2, buf)) != 0) {
	if (strcmp(buf, ".") == 0)
	    continue;
	if (strcmp(buf, "..") == 0) {
	    if (stat(".", &sb) < 0)
		fail("cannot stat current directory");
	    name = ino2name(sb.st_ino);
	    len = strlen(name);
	    cp -= len + 1;
	    strcpy(cp, name);
	    cp[len] = '/';
	    free(name);
	    xchdir("..");
	} else {
	    cp -= 3;
	    strncpy(cp, "../", 3);
	    xchdir(buf);
	}
    }
    strcpy(outpath, cp);
}