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ValdikSS 2017-09-07 16:01:19 +03:00
parent 2f0429027d
commit 64c93d29de
1 changed files with 12 additions and 118 deletions
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126
goodbyedpi.c
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@ -296,141 +296,35 @@ int main(int argc, char *argv[]) {
while (1) {
if (WinDivertRecv(w_filter, packet, sizeof(packet), &addr, &packetLen)) {
//printf("Got %s packet, len=%d!\n", addr.Direction ? "inbound" : "outbound",
// packetLen);
should_reinject = 1;
should_recalc_checksum = 0;
printf("Got %s packet, len=%d!\n", addr.Direction ? "inbound" : "outbound",
packetLen);
// do nothing for DATA packet
if (WinDivertHelperParsePacket(packet, packetLen, &ppIpHdr,
NULL, NULL, NULL, &ppTcpHdr, NULL, &packet_data, &packet_dataLen)) {
//printf("Got parsed packet, len=%d!\n", packet_dataLen);
/* Got a packet WITH DATA */
/* Handle INBOUND packet with data and find HTTP REDIRECT in there */
if (addr.Direction == WINDIVERT_DIRECTION_INBOUND && packet_dataLen > 16) {
/* If INBOUND packet with DATA (tcp.Ack) */
/* Drop packets from filter with HTTP 30x Redirect */
if (do_passivedpi && is_passivedpi_redirect(packet_data, packet_dataLen)) {
//printf("Dropping HTTP Redirect packet!\n");
should_reinject = 0;
}
}
/* Handle OUTBOUND packet, search for Host header */
else if (addr.Direction == WINDIVERT_DIRECTION_OUTBOUND &&
packet_dataLen > 16 && ppTcpHdr->DstPort == htons(80) &&
find_http_method_end(packet_data,
(do_fragment_http ? http_fragment_size : 0)) &&
(do_host || do_host_removespace))
{
data_addr = find_host_header(packet_data, packet_dataLen);
if (data_addr) {
if (do_host) {
/* Replace "Host: " with "hoSt: " */
memcpy(data_addr, http_host_replace, strlen(http_host_replace));
should_recalc_checksum = 1;
//printf("Replaced Host header!\n");
}
if (do_additional_space && do_host_removespace) {
/* End of "Host:" without trailing space */
host_addr = data_addr + strlen(http_host_find) - 1;
method_addr = find_http_method_end(packet_data,
(do_fragment_http ? http_fragment_size : 0));
if (method_addr) {
memmove(method_addr + 1, method_addr, (PVOID)host_addr - (PVOID)method_addr);
should_recalc_checksum = 1;
}
}
else if (do_host_removespace) {
host_addr = data_addr + strlen(http_host_find);
data_addr_rn = dumb_memmem(host_addr,
packet_dataLen - ((PVOID)host_addr - packet_data),
"\r\n", 2);
if (data_addr_rn) {
/* We move Host header value by one byte to the left and then
* "insert" stolen space to the end of User-Agent value because
* some web servers are not tolerant to additional space in the
* end of Host header.
*
* Nothing is done if User-Agent header is missing.
*/
host_len = data_addr_rn - host_addr;
useragent_addr = find_useragent_header(packet_data, packet_dataLen);
if (host_len <= 253 && useragent_addr) {
useragent_addr += strlen(http_useragent_find);
/* useragent_addr is in the beginning of User-Agent value */
data_len = packet_dataLen - ((PVOID)useragent_addr - packet_data);
data_addr_rn = dumb_memmem(useragent_addr,
data_len, "\r\n", 2);
/* data_addr_rn is in the end of User-Agent value */
if (data_addr_rn) {
if (useragent_addr > host_addr) {
/* User-Agent goes AFTER Host header */
data_len = (PVOID)data_addr_rn - (PVOID)host_addr;
/* Move one byte to the LEFT from "Host:"
* to the end of User-Agent
*/
memmove(host_addr - 1, host_addr, data_len);
/* Put space in the end of User-Agent header */
*(char*)(data_addr_rn - 1) = ' ';
should_recalc_checksum = 1;
//printf("Replaced Host header!\n");
}
else {
/* User-Agent goes BEFORE Host header */
data_len = (PVOID)host_addr - (PVOID)data_addr_rn - 1;
/* Move one byte to the RIGHT from the end of User-Agent
* to the "Host:"
*/
memmove(data_addr_rn + 1, data_addr_rn, data_len);
/* Put space in the end of User-Agent header */
*(char*)(data_addr_rn) = ' ';
should_recalc_checksum = 1;
//printf("Replaced Host header!\n");
}
} /* if (dara_addr_rn) */
} /* if (host_len <= 253 && useragent_addr) */
} /* if (data_addr_rn) */
} /* else if (do_host_removespace) */
} /* if (data_addr) */
} /* Handle OUTBOUND packet with data */
} /* Handle packet with data */
/* Else if we got TCP packet without data */
// reduce window size on non-data packet
else if (WinDivertHelperParsePacket(packet, packetLen, &ppIpHdr,
NULL, NULL, NULL, &ppTcpHdr, NULL, NULL, NULL)) {
/* If we got SYN+ACK packet */
if (addr.Direction == WINDIVERT_DIRECTION_INBOUND &&
ppTcpHdr->Syn == 1) {
//printf("Changing Window Size!\n");
printf("Changing Window Size!\n");
if (do_fragment_http && ppTcpHdr->SrcPort == htons(80)) {
change_window_size(packet, http_fragment_size);
should_recalc_checksum = 1;
WinDivertHelperCalcChecksums(packet, packetLen, 0);
}
else if (do_fragment_https && ppTcpHdr->SrcPort != htons(80)) {
change_window_size(packet, https_fragment_size);
should_recalc_checksum = 1;
}
}
}
if (should_reinject) {
//printf("Re-injecting!\n");
if (should_recalc_checksum) {
WinDivertHelperCalcChecksums(packet, packetLen, 0);
}
WinDivertSend(w_filter, packet, packetLen, &addr, NULL);
}
}
// uncomment this to make it work
//WinDivertHelperCalcChecksums(packet, packetLen, 0);
WinDivertSend(w_filter, packet, packetLen, &addr, NULL);
}
else {
// error, ignore
printf("Error receiving packet!\n");