// This file Copyright © 2008-2022 Mnemosyne LLC. // It may be used under GPLv2 (SPDX: GPL-2.0), GPLv3 (SPDX: GPL-3.0), // or any future license endorsed by Mnemosyne LLC. // License text can be found in the licenses/ folder. #include #include #include /* bsearch(), qsort() */ #include #include "transmission.h" #include "blocklist.h" #include "error.h" #include "file.h" #include "log.h" #include "net.h" #include "tr-assert.h" #include "utils.h" /*** **** PRIVATE ***/ struct tr_ipv4_range { uint32_t begin; uint32_t end; }; struct tr_blocklistFile { bool isEnabled; tr_sys_file_t fd; size_t ruleCount; uint64_t byteCount; char* filename; struct tr_ipv4_range* rules; }; static void blocklistClose(tr_blocklistFile* b) { if (b->rules != nullptr) { tr_sys_file_unmap(b->rules, b->byteCount, nullptr); tr_sys_file_close(b->fd, nullptr); b->rules = nullptr; b->ruleCount = 0; b->byteCount = 0; b->fd = TR_BAD_SYS_FILE; } } static void blocklistLoad(tr_blocklistFile* b) { tr_error* error = nullptr; char const* err_fmt = _("Couldn't read \"%1$s\": %2$s"); blocklistClose(b); auto info = tr_sys_path_info{}; if (!tr_sys_path_get_info(b->filename, 0, &info, nullptr)) { return; } auto const byteCount = info.size; if (byteCount == 0) { return; } auto const fd = tr_sys_file_open(b->filename, TR_SYS_FILE_READ, 0, &error); if (fd == TR_BAD_SYS_FILE) { tr_logAddError(err_fmt, b->filename, error->message); tr_error_free(error); return; } b->rules = static_cast(tr_sys_file_map_for_reading(fd, 0, byteCount, &error)); if (b->rules == nullptr) { tr_logAddError(err_fmt, b->filename, error->message); tr_sys_file_close(fd, nullptr); tr_error_free(error); return; } b->fd = fd; b->byteCount = byteCount; b->ruleCount = byteCount / sizeof(struct tr_ipv4_range); char* const base = tr_sys_path_basename(b->filename, nullptr); tr_logAddInfo(_("Blocklist \"%s\" contains %zu entries"), base, b->ruleCount); tr_free(base); } static void blocklistEnsureLoaded(tr_blocklistFile* b) { if (b->rules == nullptr) { blocklistLoad(b); } } static int compareAddressToRange(void const* va, void const* vb) { auto const* a = static_cast(va); auto const* b = static_cast(vb); if (*a < b->begin) { return -1; } if (*a > b->end) { return 1; } return 0; } static void blocklistDelete(tr_blocklistFile* b) { blocklistClose(b); tr_sys_path_remove(b->filename, nullptr); } /*** **** PACKAGE-VISIBLE ***/ tr_blocklistFile* tr_blocklistFileNew(char const* filename, bool isEnabled) { auto* const b = tr_new0(tr_blocklistFile, 1); b->fd = TR_BAD_SYS_FILE; b->filename = tr_strdup(filename); b->isEnabled = isEnabled; return b; } char const* tr_blocklistFileGetFilename(tr_blocklistFile const* b) { return b->filename; } void tr_blocklistFileFree(tr_blocklistFile* b) { blocklistClose(b); tr_free(b->filename); tr_free(b); } bool tr_blocklistFileExists(tr_blocklistFile const* b) { return tr_sys_path_exists(b->filename, nullptr); } int tr_blocklistFileGetRuleCount(tr_blocklistFile const* b) { blocklistEnsureLoaded((tr_blocklistFile*)b); return b->ruleCount; } bool tr_blocklistFileIsEnabled(tr_blocklistFile* b) { return b->isEnabled; } void tr_blocklistFileSetEnabled(tr_blocklistFile* b, bool isEnabled) { TR_ASSERT(b != nullptr); b->isEnabled = isEnabled; } bool tr_blocklistFileHasAddress(tr_blocklistFile* b, tr_address const* addr) { TR_ASSERT(tr_address_is_valid(addr)); if (!b->isEnabled || addr->type == TR_AF_INET6) { return false; } blocklistEnsureLoaded(b); if (b->rules == nullptr || b->ruleCount == 0) { return false; } auto const needle = ntohl(addr->addr.addr4.s_addr); auto const* range = static_cast( bsearch(&needle, b->rules, b->ruleCount, sizeof(struct tr_ipv4_range), compareAddressToRange)); return range != nullptr; } /* * 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(char const* line, struct tr_ipv4_range* range) { int b[4]; int e[4]; char str[64]; tr_address addr; char const* walk = strrchr(line, ':'); if (walk == nullptr) { return false; } ++walk; /* walk past the colon */ if (sscanf( walk, "%d.%d.%d.%d-%d.%d.%d.%d", TR_ARG_TUPLE(&b[0], &b[1], &b[2], &b[3]), TR_ARG_TUPLE(&e[0], &e[1], &e[2], &e[3])) != 8) { return false; } tr_snprintf(str, sizeof(str), "%d.%d.%d.%d", TR_ARG_TUPLE(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", TR_ARG_TUPLE(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(char const* line, struct tr_ipv4_range* range) { int unk = 0; int a[4]; int b[4]; char str[32]; tr_address addr; if (sscanf( line, "%3d.%3d.%3d.%3d - %3d.%3d.%3d.%3d , %3d , ", TR_ARG_TUPLE(&a[0], &a[1], &a[2], &a[3]), TR_ARG_TUPLE(&b[0], &b[1], &b[2], &b[3]), &unk) != 9) { return false; } tr_snprintf(str, sizeof(str), "%d.%d.%d.%d", TR_ARG_TUPLE(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", TR_ARG_TUPLE(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; } /* * CIDR notation: "0.0.0.0/8", IPv4 only * https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing#CIDR_notation */ static bool parseLine3(char const* line, struct tr_ipv4_range* range) { unsigned int ip[4]; unsigned int pflen = 0; uint32_t ip_u = 0; uint32_t mask = 0xffffffff; if (sscanf(line, "%u.%u.%u.%u/%u", TR_ARG_TUPLE(&ip[0], &ip[1], &ip[2], &ip[3]), &pflen) != 5) { return false; } if (pflen > 32 || ip[0] > 0xff || ip[1] > 0xff || ip[2] > 0xff || ip[3] > 0xff) { return false; } /* this is host order */ mask <<= 32 - pflen; ip_u = ip[0] << 24 | ip[1] << 16 | ip[2] << 8 | ip[3]; /* fill the non-prefix bits the way we need it */ range->begin = ip_u & mask; range->end = ip_u | (~mask); return true; } static bool parseLine(char const* line, struct tr_ipv4_range* range) { return parseLine1(line, range) || parseLine2(line, range) || parseLine3(line, range); } static int compareAddressRangesByFirstAddress(void const* va, void const* vb) { auto const* a = static_cast(va); auto const* b = static_cast(vb); if (a->begin != b->begin) { return a->begin < b->begin ? -1 : 1; } return 0; } int tr_blocklistFileSetContent(tr_blocklistFile* b, char const* filename) { int inCount = 0; char line[2048]; char const* err_fmt = _("Couldn't read \"%1$s\": %2$s"); // TODO: should be a vector struct tr_ipv4_range* ranges = nullptr; size_t ranges_alloc = 0; size_t ranges_count = 0; tr_error* error = nullptr; if (filename == nullptr) { blocklistDelete(b); return 0; } auto const in = tr_sys_file_open(filename, TR_SYS_FILE_READ, 0, &error); if (in == TR_BAD_SYS_FILE) { tr_logAddError(err_fmt, filename, error->message); tr_error_free(error); return 0; } blocklistClose(b); auto const out = tr_sys_file_open(b->filename, TR_SYS_FILE_WRITE | TR_SYS_FILE_CREATE | TR_SYS_FILE_TRUNCATE, 0666, &error); if (out == TR_BAD_SYS_FILE) { tr_logAddError(err_fmt, b->filename, error->message); tr_error_free(error); tr_sys_file_close(in, nullptr); return 0; } /* load the rules into memory */ while (tr_sys_file_read_line(in, line, sizeof(line), nullptr)) { struct tr_ipv4_range range; ++inCount; if (!parseLine(line, &range)) { /* don't try to display the actual lines - it causes issues */ tr_logAddError(_("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* keep = ranges; /* sort */ qsort(ranges, ranges_count, sizeof(struct tr_ipv4_range), compareAddressRangesByFirstAddress); /* merge */ for (size_t i = 1; i < ranges_count; ++i) { struct tr_ipv4_range const* r = &ranges[i]; if (keep->end < r->begin) { *++keep = *r; } else if (keep->end < r->end) { keep->end = r->end; } } ranges_count = keep + 1 - ranges; #ifdef TR_ENABLE_ASSERTS /* sanity checks: make sure the rules are sorted in ascending order and don't overlap */ { for (size_t i = 0; i < ranges_count; ++i) { TR_ASSERT(ranges[i].begin <= ranges[i].end); } for (size_t i = 1; i < ranges_count; ++i) { TR_ASSERT(ranges[i - 1].end < ranges[i].begin); } } #endif } if (!tr_sys_file_write(out, ranges, sizeof(struct tr_ipv4_range) * ranges_count, nullptr, &error)) { tr_logAddError(_("Couldn't save file \"%1$s\": %2$s"), b->filename, error->message); tr_error_free(error); } else { char* base = tr_sys_path_basename(b->filename, nullptr); tr_logAddInfo(_("Blocklist \"%s\" updated with %zu entries"), base, ranges_count); tr_free(base); } tr_free(ranges); tr_sys_file_close(out, nullptr); tr_sys_file_close(in, nullptr); blocklistLoad(b); return ranges_count; }