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byedpi/desync.c
ruti 276073ddea More pedantic code
2024-11-09 18:07:27 +03:00

639 lines
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#define _GNU_SOURCE
#include "desync.h"
#include <stdio.h>
#include <string.h>
#ifndef _WIN32
#include <unistd.h>
#include <time.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/mman.h>
#include <arpa/inet.h>
#include <fcntl.h>
#ifndef __linux__
#include <netinet/tcp.h>
#else
#include <linux/tcp.h>
#include <linux/filter.h>
#endif
#else
#include <winsock2.h>
#include <ws2tcpip.h>
#include <mswsock.h>
#endif
#define STR_MODE
#include "params.h"
#include "packets.h"
#include "error.h"
int setttl(int fd, int ttl)
{
int ret6 = setsockopt(fd, IPPROTO_IPV6,
IPV6_UNICAST_HOPS, (char *)&ttl, sizeof(ttl));
int ret4 = setsockopt(fd, IPPROTO_IP,
IP_TTL, (char *)&ttl, sizeof(ttl));
if (ret4 && ret6) {
uniperror("setttl");
return -1;
}
return 0;
}
#ifdef __linux__
static int drop_sack(int fd)
{
struct sock_filter code[] = {
{ 0x30, 0, 0, 0x0000000c },
{ 0x74, 0, 0, 0x00000004 },
{ 0x35, 0, 3, 0x0000000b },
{ 0x30, 0, 0, 0x00000022 },
{ 0x15, 0, 1, 0x00000005 },
{ 0x6, 0, 0, 0x00000000 },
{ 0x6, 0, 0, 0x00040000 },
};
struct sock_fprog bpf = {
.len = sizeof(code)/sizeof(*code),
.filter = code
};
if (setsockopt(fd, SOL_SOCKET,
SO_ATTACH_FILTER, (char *)&bpf, sizeof(bpf)) == -1) {
uniperror("setsockopt SO_ATTACH_FILTER");
return -1;
}
return 0;
}
#endif
#ifndef _WIN32
static inline void delay(long ms)
{
struct timespec time = {
.tv_nsec = ms * 1e6
};
nanosleep(&time, 0);
}
#else
#define delay(ms) Sleep(ms)
#endif
#ifdef __linux__
static void wait_send(int sfd)
{
for (int i = 0; params.wait_send && i < 500; i++) {
struct tcp_info tcpi = {};
socklen_t ts = sizeof(tcpi);
if (getsockopt(sfd, IPPROTO_TCP,
TCP_INFO, (char *)&tcpi, &ts) < 0) {
perror("getsockopt TCP_INFO");
break;
}
if (tcpi.tcpi_state != 1) {
LOG(LOG_E, "state: %d\n", tcpi.tcpi_state);
return;
}
size_t s = (char *)&tcpi.tcpi_notsent_bytes - (char *)&tcpi.tcpi_state;
if (ts < s) {
LOG(LOG_E, "tcpi_notsent_bytes not provided\n");
params.wait_send = 0;
break;
}
if (tcpi.tcpi_notsent_bytes == 0) {
return;
}
LOG(LOG_S, "not sent after %d ms\n", i);
delay(1);
}
delay(params.sfdelay);
}
#define wait_send_if_support(sfd) \
if (params.wait_send) wait_send(sfd)
#else
#define wait_send(sfd) delay(params.sfdelay)
#define wait_send_if_support(sfd) // :(
#endif
#ifdef __linux__
static ssize_t send_fake(int sfd, const char *buffer,
int cnt, long pos, struct desync_params *opt)
{
struct sockaddr_in6 addr = {};
socklen_t addr_size = sizeof(addr);
if (opt->md5sig) {
if (getpeername(sfd,
(struct sockaddr *)&addr, &addr_size) < 0) {
uniperror("getpeername");
return -1;
}
}
struct packet pkt;
if (opt->fake_data.data) {
pkt = opt->fake_data;
}
else {
pkt = cnt != IS_HTTP ? fake_tls : fake_http;
}
if (opt->fake_offset) {
if (pkt.size > opt->fake_offset) {
pkt.size -= opt->fake_offset;
pkt.data += opt->fake_offset;
}
else pkt.size = 0;
}
int fds[2];
if (pipe(fds) < 0) {
uniperror("pipe");
return -1;
}
char *p = 0;
ssize_t len = -1;
while (1) {
p = mmap(0, pos, PROT_WRITE | PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
if (p == MAP_FAILED) {
uniperror("mmap");
p = 0;
break;
}
memcpy(p, pkt.data, pkt.size < pos ? pkt.size : pos);
if (setttl(sfd, opt->ttl ? opt->ttl : 8) < 0) {
break;
}
if (opt->md5sig) {
struct tcp_md5sig md5 = {
.tcpm_keylen = 5
};
memcpy(&md5.tcpm_addr, &addr, addr_size);
if (setsockopt(sfd, IPPROTO_TCP,
TCP_MD5SIG, (char *)&md5, sizeof(md5)) < 0) {
uniperror("setsockopt TCP_MD5SIG");
break;
}
}
if (opt->ip_options
&& setsockopt(sfd, IPPROTO_IP, IP_OPTIONS,
opt->ip_options, opt->ip_options_len) < 0) {
uniperror("setsockopt IP_OPTIONS");
//break;
}
struct iovec vec = { .iov_base = p, .iov_len = pos };
len = vmsplice(fds[1], &vec, 1, SPLICE_F_GIFT);
if (len < 0) {
uniperror("vmsplice");
break;
}
len = splice(fds[0], 0, sfd, 0, len, 0);
if (len < 0) {
uniperror("splice");
break;
}
wait_send(sfd);
memcpy(p, buffer, pos);
if (setttl(sfd, params.def_ttl) < 0) {
break;
}
if (opt->ip_options
&& setsockopt(sfd, IPPROTO_IP,
IP_OPTIONS, opt->ip_options, 0) < 0) {
uniperror("setsockopt IP_OPTIONS");
//break;
}
if (opt->md5sig) {
struct tcp_md5sig md5 = {
.tcpm_keylen = 0
};
memcpy(&md5.tcpm_addr, &addr, addr_size);
if (setsockopt(sfd, IPPROTO_TCP,
TCP_MD5SIG, (char *)&md5, sizeof(md5)) < 0) {
uniperror("setsockopt TCP_MD5SIG");
break;
}
}
break;
}
if (p) munmap(p, pos);
close(fds[0]);
close(fds[1]);
return len;
}
#endif
#ifdef _WIN32
OVERLAPPED ov = {};
static ssize_t send_fake(int sfd, const char *buffer,
int cnt, long pos, struct desync_params *opt)
{
struct packet pkt;
if (opt->fake_data.data) {
pkt = opt->fake_data;
}
else {
pkt = cnt != IS_HTTP ? fake_tls : fake_http;
}
if (opt->fake_offset) {
if (pkt.size > opt->fake_offset) {
pkt.size -= opt->fake_offset;
pkt.data += opt->fake_offset;
}
else pkt.size = 0;
}
char path[MAX_PATH], temp[MAX_PATH + 1];
int ps = GetTempPath(sizeof(temp), temp);
if (!ps) {
uniperror("GetTempPath");
return -1;
}
if (!GetTempFileName(temp, "t", 0, path)) {
uniperror("GetTempFileName");
return -1;
}
LOG(LOG_L, "temp file: %s\n", path);
HANDLE hfile = CreateFileA(path, GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, CREATE_ALWAYS,
FILE_ATTRIBUTE_TEMPORARY | FILE_FLAG_DELETE_ON_CLOSE, NULL);
if (hfile == INVALID_HANDLE_VALUE) {
uniperror("CreateFileA");
return -1;
}
ssize_t len = -1;
while (1) {
ov.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
if (!ov.hEvent) {
uniperror("CreateEvent");
break;
}
DWORD wrtcnt = 0;
if (!WriteFile(hfile, pkt.data, pkt.size < pos ? pkt.size : pos, &wrtcnt, 0)) {
uniperror("WriteFile");
break;
}
if (pkt.size < pos) {
if (SetFilePointer(hfile, pos, 0, FILE_BEGIN) == INVALID_SET_FILE_POINTER) {
uniperror("SetFilePointer");
break;
}
if (!SetEndOfFile(hfile)) {
uniperror("SetFileEnd");
break;
}
}
if (SetFilePointer(hfile, 0, 0, FILE_BEGIN) == INVALID_SET_FILE_POINTER) {
uniperror("SetFilePointer");
break;
}
if (setttl(sfd, opt->ttl ? opt->ttl : 8) < 0) {
break;
}
if (!TransmitFile(sfd, hfile, pos, pos, &ov,
NULL, TF_USE_KERNEL_APC | TF_WRITE_BEHIND)) {
if ((GetLastError() != ERROR_IO_PENDING)
&& (WSAGetLastError() != WSA_IO_PENDING)) {
uniperror("TransmitFile");
break;
}
}
wait_send(sfd);
if (SetFilePointer(hfile, 0, 0, FILE_BEGIN) == INVALID_SET_FILE_POINTER) {
uniperror("SetFilePointer");
break;
}
if (!WriteFile(hfile, buffer, pos, &wrtcnt, 0)) {
uniperror("WriteFile");
break;
}
if (setttl(sfd, params.def_ttl) < 0) {
break;
}
len = pos;
break;
}
if (!CloseHandle(hfile)
|| (ov.hEvent && !CloseHandle(ov.hEvent))) {
uniperror("CloseHandle");
return -1;
}
return len;
}
#endif
static ssize_t send_oob(int sfd, char *buffer,
ssize_t n, long pos, const char *c)
{
char rchar = buffer[pos];
buffer[pos] = c[1] ? c[0] : 'a';
ssize_t len = send(sfd, buffer, pos + 1, MSG_OOB);
buffer[pos] = rchar;
if (len < 0) {
uniperror("send");
return -1;
}
wait_send_if_support(sfd);
len--;
if (len != pos) {
return len;
}
return len;
}
static ssize_t send_disorder(int sfd,
const char *buffer, long pos)
{
int bttl = 1;
if (setttl(sfd, bttl) < 0) {
return -1;
}
ssize_t len = send(sfd, buffer, pos, 0);
if (len < 0) {
uniperror("send");
}
else wait_send_if_support(sfd);
if (setttl(sfd, params.def_ttl) < 0) {
return -1;
}
return len;
}
static ssize_t send_late_oob(int sfd, char *buffer,
ssize_t n, long pos, const char *c)
{
int bttl = 1;
if (setttl(sfd, bttl) < 0) {
return -1;
}
ssize_t len = send_oob(sfd, buffer, n, pos, c);
if (len < 0) {
uniperror("send");
}
if (setttl(sfd, params.def_ttl) < 0) {
return -1;
}
return len;
}
static long gen_offset(long pos, int flag,
ssize_t n, long lp, int type, int hp, int len)
{
if (flag & (OFFSET_SNI | OFFSET_HOST)) {
if (!hp || ((flag & OFFSET_SNI) && type != IS_HTTPS)) {
return -1;
}
pos += hp;
if (flag & OFFSET_END)
pos += len;
else if (flag & OFFSET_MID)
pos += (len / 2);
else if (flag & OFFSET_RAND)
pos += (rand() % len);
}
else if (flag & OFFSET_RAND) {
pos += lp + (rand() % (n - lp));
}
else if (flag & OFFSET_MID) {
pos += (n / 2);
}
else if (pos < 0 || (flag & OFFSET_END)) {
pos += n;
}
return pos;
}
ssize_t desync(int sfd, char *buffer, size_t bfsize,
ssize_t n, ssize_t offset, const struct sockaddr *dst, int dp_c)
{
struct desync_params dp = params.dp[dp_c];
char *host = 0;
int len = 0, type = 0, host_pos = 0;
if (offset == 0) {
if ((len = parse_tls(buffer, n, &host))) {
type = IS_HTTPS;
}
else if ((len = parse_http(buffer, n, &host, 0))) {
type = IS_HTTP;
}
if (len && host) {
LOG(LOG_S, "host: %.*s (%zd)\n",
len, host, host - buffer);
host_pos = host - buffer;
}
else {
size_t s = n > 16 ? 16 : n - (n % 4);
char hex[s * 2 + 1], *b = buffer;
for (size_t i = 0; i < s; i += 4)
snprintf(hex + i * 2, sizeof(hex) - i * 2,
"%02x%02x%02x%02x", b[i],b[i+1],b[i+2],b[i+3]);
LOG(LOG_S, "bytes: %s (%zd)\n", s ? hex : "", n);
}
}
// modify packet
if (type == IS_HTTP && dp.mod_http) {
LOG(LOG_S, "modify HTTP: n=%zd\n", n);
if (mod_http(buffer, n, dp.mod_http)) {
LOG(LOG_E, "mod http error\n");
return -1;
}
}
else if (type == IS_HTTPS && dp.tlsrec_n) {
long lp = 0;
struct part part;
int i = 0, r = 0, rc = 0;
for (; r > 0 || i < dp.tlsrec_n; rc++, r--) {
if (r <= 0) {
part = dp.tlsrec[i];
r = part.r; i++;
}
long pos = rc * 5;
pos += gen_offset(part.pos,
part.flag, n - pos - 5, lp, type, host_pos - 5, len);
pos += (long)part.s * (part.r - r);
if (pos < lp) {
LOG(LOG_E, "tlsrec cancel: %ld < %ld\n", pos, lp);
break;
}
if (!part_tls(buffer + lp,
bfsize - lp, n - lp, pos - lp)) {
LOG(LOG_E, "tlsrec error: pos=%ld, n=%zd\n", pos, n);
break;
}
LOG(LOG_S, "tlsrec: pos=%ld, n=%zd\n", pos, n);
n += 5;
lp = pos + 5;
}
}
#ifdef __linux__
if (!offset && dp.drop_sack && drop_sack(sfd)) {
return -1;
}
#endif
long lp = 0;
struct part part;
int i = 0, r = 0;
for (; r > 0 || i < dp.parts_n; r--) {
if (r <= 0) {
part = dp.parts[i];
r = part.r; i++;
}
long pos = gen_offset(part.pos,
part.flag, n, lp, type, host_pos, len);
pos += (long)part.s * (part.r - r);
if (!(part.flag & OFFSET_START) && offset && pos <= offset) {
LOG(LOG_S, "offset: %zd, skip\n", offset);
continue;
}
if (pos < 0 || pos > n || pos < lp) {
LOG(LOG_E, "split cancel: pos=%ld-%ld, n=%zd\n", lp, pos, n);
break;
}
ssize_t s = 0;
switch (part.m) {
#ifdef FAKE_SUPPORT
case DESYNC_FAKE:
if (pos != lp) s = send_fake(sfd,
buffer + lp, type, pos - lp, &dp);
break;
#endif
case DESYNC_DISORDER:
s = send_disorder(sfd,
buffer + lp, pos - lp);
break;
case DESYNC_OOB:
s = send_oob(sfd,
buffer + lp, n - lp, pos - lp, dp.oob_char);
break;
case DESYNC_DISOOB:
s = send_late_oob(sfd,
buffer + lp, n - lp, pos - lp, dp.oob_char);
break;
case DESYNC_SPLIT:
case DESYNC_NONE:
s = send(sfd, buffer + lp, pos - lp, 0);
wait_send_if_support(sfd);
break;
default:
return -1;
}
LOG(LOG_S, "split: pos=%ld-%ld (%zd), m: %s\n", lp, pos, s, demode_str[part.m]);
if (s < 0) {
if (get_e() == EAGAIN) {
return lp;
}
return -1;
}
else if (s != (pos - lp)) {
LOG(LOG_E, "%zd != %ld\n", s, pos - lp);
return lp + s;
}
lp = pos;
}
// send all/rest
if (lp < n) {
LOG((lp ? LOG_S : LOG_L), "send: pos=%ld-%zd\n", lp, n);
if (send(sfd, buffer + lp, n - lp, 0) < 0) {
if (get_e() == EAGAIN) {
return lp;
}
uniperror("send");
return -1;
}
}
return n;
}
int post_desync(int sfd, int dp_c)
{
struct desync_params *dp = &params.dp[dp_c];
#ifdef __linux__
if (dp->drop_sack) {
if (setsockopt(sfd, SOL_SOCKET,
SO_DETACH_FILTER, &dp_c, sizeof(dp_c)) == -1) {
uniperror("setsockopt SO_DETACH_FILTER");
return -1;
}
}
#endif
return 0;
}
ssize_t desync_udp(int sfd, char *buffer, size_t bfsize,
ssize_t n, const struct sockaddr *dst, int dp_c)
{
struct desync_params *dp = &params.dp[dp_c];
if (dp->udp_fake_count != 0) {
struct packet pkt;
if (dp->fake_data.data) {
pkt = dp->fake_data;
}
else {
pkt = fake_udp;
}
if (dp->fake_offset) {
if (pkt.size > dp->fake_offset) {
pkt.size -= dp->fake_offset;
pkt.data += dp->fake_offset;
}
else pkt.size = 0;
}
int bttl = dp->ttl ? dp->ttl : 8;
if (setttl(sfd, bttl) < 0) {
return -1;
}
for (int i = 0; i < dp->udp_fake_count; i++) {
ssize_t len = sendto(sfd, pkt.data,
pkt.size, 0, dst, sizeof(struct sockaddr_in6));
if (len < 0) {
uniperror("send");
return -1;
}
}
if (setttl(sfd, params.def_ttl) < 0) {
return -1;
}
}
return sendto(sfd, buffer, n, 0,
dst, sizeof(struct sockaddr_in6));
}
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