transmission/libtransmission/blocklist.c

432 lines
9.5 KiB
C

/*
* This file Copyright (C) Mnemosyne LLC
*
* This file is licensed by the GPL version 2. Works owned by the
* Transmission project are granted a special exemption to clause 2 (b)
* so that the bulk of its code can remain under the MIT license.
* This exemption does not extend to derived works not owned by
* the Transmission project.
*
* $Id$
*/
#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h> /* bsearch (), qsort () */
#include <string.h>
#include <unistd.h> /* unlink () */
#ifdef WIN32
#include <w32api.h>
#define WINVER WindowsXP
#include <windows.h>
#define PROT_READ PAGE_READONLY
#define MAP_PRIVATE FILE_MAP_COPY
#endif
#ifndef WIN32
#include <sys/mman.h>
#endif
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "transmission.h"
#include "blocklist.h"
#include "net.h"
#include "utils.h"
#ifndef O_BINARY
#define O_BINARY 0
#endif
/***
**** PRIVATE
***/
struct tr_ipv4_range
{
uint32_t begin;
uint32_t end;
};
struct tr_blocklist
{
bool isEnabled;
int fd;
size_t ruleCount;
size_t byteCount;
char * filename;
struct tr_ipv4_range * rules;
};
static void
blocklistClose (tr_blocklist * b)
{
if (b->rules)
{
munmap (b->rules, b->byteCount);
close (b->fd);
b->rules = NULL;
b->ruleCount = 0;
b->byteCount = 0;
b->fd = -1;
}
}
static void
blocklistLoad (tr_blocklist * b)
{
int fd;
size_t byteCount;
struct stat st;
const char * err_fmt = _("Couldn't read \"%1$s\": %2$s");
blocklistClose (b);
if (stat (b->filename, &st) == -1)
return;
fd = open (b->filename, O_RDONLY | O_BINARY);
if (fd == -1)
{
tr_err (err_fmt, b->filename, tr_strerror (errno));
return;
}
byteCount = (size_t) st.st_size;
b->rules = mmap (NULL, byteCount, PROT_READ, MAP_PRIVATE, fd, 0);
if (!b->rules)
{
tr_err (err_fmt, b->filename, tr_strerror (errno));
close (fd);
return;
}
b->fd = fd;
b->byteCount = byteCount;
b->ruleCount = byteCount / sizeof (struct tr_ipv4_range);
{
char * base = tr_basename (b->filename);
tr_inf (_("Blocklist \"%s\" contains %zu entries"), base, b->ruleCount);
tr_free (base);
}
}
static void
blocklistEnsureLoaded (tr_blocklist * b)
{
if (!b->rules)
blocklistLoad (b);
}
static int
compareAddressToRange (const void * va,
const void * vb)
{
const uint32_t * a = va;
const struct tr_ipv4_range * b = vb;
if (*a < b->begin) return -1;
if (*a > b->end) return 1;
return 0;
}
static void
blocklistDelete (tr_blocklist * b)
{
blocklistClose (b);
unlink (b->filename);
}
/***
**** PACKAGE-VISIBLE
***/
tr_blocklist *
_tr_blocklistNew (const char * filename, bool isEnabled)
{
tr_blocklist * b;
b = tr_new0 (tr_blocklist, 1);
b->fd = -1;
b->filename = tr_strdup (filename);
b->isEnabled = isEnabled;
return b;
}
const char*
_tr_blocklistGetFilename (const tr_blocklist * b)
{
return b->filename;
}
void
_tr_blocklistFree (tr_blocklist * b)
{
blocklistClose (b);
tr_free (b->filename);
tr_free (b);
}
int
_tr_blocklistExists (const tr_blocklist * b)
{
struct stat st;
return !stat (b->filename, &st);
}
int
_tr_blocklistGetRuleCount (const tr_blocklist * b)
{
blocklistEnsureLoaded ((tr_blocklist*)b);
return b->ruleCount;
}
int
_tr_blocklistIsEnabled (tr_blocklist * b)
{
return b->isEnabled;
}
void
_tr_blocklistSetEnabled (tr_blocklist * b, bool isEnabled)
{
b->isEnabled = isEnabled ? 1 : 0;
}
int
_tr_blocklistHasAddress (tr_blocklist * b, const tr_address * addr)
{
uint32_t needle;
const struct tr_ipv4_range * range;
assert (tr_address_is_valid (addr));
if (!b->isEnabled || addr->type == TR_AF_INET6)
return 0;
blocklistEnsureLoaded (b);
if (!b->rules || !b->ruleCount)
return 0;
needle = ntohl (addr->addr.addr4.s_addr);
range = bsearch (&needle,
b->rules,
b->ruleCount,
sizeof (struct tr_ipv4_range),
compareAddressToRange);
return range != NULL;
}
/*
* P2P plaintext format: "comment:x.x.x.x-y.y.y.y"
* http://wiki.phoenixlabs.org/wiki/P2P_Format
* http://en.wikipedia.org/wiki/PeerGuardian#P2P_plaintext_format
*/
static bool
parseLine1 (const char * line, struct tr_ipv4_range * range)
{
char * walk;
int b[4];
int e[4];
char str[64];
tr_address addr;
walk = strrchr (line, ':');
if (!walk)
return false;
++walk; /* walk past the colon */
if (sscanf (walk, "%d.%d.%d.%d-%d.%d.%d.%d",
&b[0], &b[1], &b[2], &b[3],
&e[0], &e[1], &e[2], &e[3]) != 8)
return false;
tr_snprintf (str, sizeof (str), "%d.%d.%d.%d", b[0], b[1], b[2], b[3]);
if (!tr_address_from_string (&addr, str))
return false;
range->begin = ntohl (addr.addr.addr4.s_addr);
tr_snprintf (str, sizeof (str), "%d.%d.%d.%d", e[0], e[1], e[2], e[3]);
if (!tr_address_from_string (&addr, str))
return false;
range->end = ntohl (addr.addr.addr4.s_addr);
return true;
}
/*
* DAT format: "000.000.000.000 - 000.255.255.255 , 000 , invalid ip"
* http://wiki.phoenixlabs.org/wiki/DAT_Format
*/
static bool
parseLine2 (const char * line, struct tr_ipv4_range * range)
{
int unk;
int a[4];
int b[4];
char str[32];
tr_address addr;
if (sscanf (line, "%3d.%3d.%3d.%3d - %3d.%3d.%3d.%3d , %3d , ",
&a[0], &a[1], &a[2], &a[3],
&b[0], &b[1], &b[2], &b[3],
&unk) != 9)
return false;
tr_snprintf (str, sizeof (str), "%d.%d.%d.%d", a[0], a[1], a[2], a[3]);
if (!tr_address_from_string (&addr, str))
return false;
range->begin = ntohl (addr.addr.addr4.s_addr);
tr_snprintf (str, sizeof (str), "%d.%d.%d.%d", b[0], b[1], b[2], b[3]);
if (!tr_address_from_string (&addr, str))
return false;
range->end = ntohl (addr.addr.addr4.s_addr);
return true;
}
static int
parseLine (const char * line, struct tr_ipv4_range * range)
{
return parseLine1 (line, range)
|| parseLine2 (line, range);
}
static int
compareAddressRangesByFirstAddress (const void * va, const void * vb)
{
const struct tr_ipv4_range * a = va;
const struct tr_ipv4_range * b = vb;
if (a->begin != b->begin)
return a->begin < b->begin ? -1 : 1;
return 0;
}
int
_tr_blocklistSetContent (tr_blocklist * b, const char * filename)
{
FILE * in;
FILE * out;
int inCount = 0;
char line[2048];
const char * err_fmt = _("Couldn't read \"%1$s\": %2$s");
struct tr_ipv4_range * ranges = NULL;
size_t ranges_alloc = 0;
size_t ranges_count = 0;
if (!filename)
{
blocklistDelete (b);
return 0;
}
in = fopen (filename, "rb");
if (!in)
{
tr_err (err_fmt, filename, tr_strerror (errno));
return 0;
}
blocklistClose (b);
out = fopen (b->filename, "wb+");
if (!out)
{
tr_err (err_fmt, b->filename, tr_strerror (errno));
fclose (in);
return 0;
}
/* load the rules into memory */
while (fgets (line, sizeof (line), in) != NULL)
{
char * walk;
struct tr_ipv4_range range;
++inCount;
/* zap the linefeed */
if ((walk = strchr (line, '\r'))) *walk = '\0';
if ((walk = strchr (line, '\n'))) *walk = '\0';
if (!parseLine (line, &range))
{
/* don't try to display the actual lines - it causes issues */
tr_err (_("blocklist skipped invalid address at line %d"), inCount);
continue;
}
if (ranges_alloc == ranges_count)
{
ranges_alloc += 4096; /* arbitrary */
ranges = tr_renew (struct tr_ipv4_range, ranges, ranges_alloc);
}
ranges[ranges_count++] = range;
}
if (ranges_count > 0) /* sort and merge */
{
struct tr_ipv4_range * r;
struct tr_ipv4_range * keep = ranges;
const struct tr_ipv4_range * end;
/* sort */
qsort (ranges, ranges_count, sizeof (struct tr_ipv4_range),
compareAddressRangesByFirstAddress);
/* merge */
for (r=ranges+1, end=ranges+ranges_count; r!=end; ++r) {
if (keep->end < r->begin)
*++keep = *r;
else if (keep->end < r->end)
keep->end = r->end;
}
ranges_count = keep + 1 - ranges;
#ifndef NDEBUG
/* sanity checks: make sure the rules are sorted
* in ascending order and don't overlap */
{
size_t i;
for (i=0; i<ranges_count; ++i)
assert (ranges[i].begin <= ranges[i].end);
for (i=1; i<ranges_count; ++i)
assert (ranges[i-1].end < ranges[i].begin);
}
#endif
}
if (fwrite (ranges, sizeof (struct tr_ipv4_range), ranges_count, out) != ranges_count)
tr_err (_("Couldn't save file \"%1$s\": %2$s"), b->filename, tr_strerror (errno));
else {
char * base = tr_basename (b->filename);
tr_inf (_("Blocklist \"%s\" updated with %zu entries"), base, ranges_count);
tr_free (base);
}
tr_free (ranges);
fclose (out);
fclose (in);
blocklistLoad (b);
return ranges_count;
}