Browse Source

Update goodbyedpi.c

pull/319/head
SashaXser 2 years ago
committed by GitHub
parent
commit
cda71e0c61
No known key found for this signature in database GPG Key ID: 4AEE18F83AFDEB23
  1. 112
      src/goodbyedpi.c

112
src/goodbyedpi.c

@ -393,46 +393,42 @@ static int find_header_and_get_info(const char *pktdata, unsigned int pktlen,
static int extract_sni(const char *pktdata, unsigned int pktlen, static int extract_sni(const char *pktdata, unsigned int pktlen,
char **hostnameaddr, unsigned int *hostnamelen) { char **hostnameaddr, unsigned int *hostnamelen) {
unsigned int ptr = 0; unsigned int ptr = 0;
unsigned const char *d = (unsigned const char *)pktdata; const unsigned char *d = (const unsigned char *)pktdata;
unsigned const char *hnaddr = 0; const unsigned char *hnaddr = NULL;
int hnlen = 0; int hnlen = 0;
while (ptr + 8 < pktlen) { while (ptr + 8 < pktlen) {
/* Search for specific Extensions sequence */
if (d[ptr] == '\0' && d[ptr+1] == '\0' && d[ptr+2] == '\0' && if (d[ptr] == '\0' && d[ptr+1] == '\0' && d[ptr+2] == '\0' &&
d[ptr+4] == '\0' && d[ptr+6] == '\0' && d[ptr+7] == '\0' && d[ptr+4] == '\0' && d[ptr+6] == '\0' && d[ptr+7] == '\0' &&
/* Check Extension length, Server Name list length
* and Server Name length relations
*/
d[ptr+3] - d[ptr+5] == 2 && d[ptr+5] - d[ptr+8] == 3) d[ptr+3] - d[ptr+5] == 2 && d[ptr+5] - d[ptr+8] == 3)
{ {
if (ptr + 8 + d[ptr+8] > pktlen) {
return FALSE;
}
hnaddr = &d[ptr+9]; hnaddr = &d[ptr+9];
hnlen = d[ptr+8]; hnlen = d[ptr+8];
/* Limit hostname size up to 253 bytes */
if (hnlen < 3 || hnlen > HOST_MAXLEN) { if (ptr + 8 + hnlen > pktlen || hnlen < 3 || hnlen > HOST_MAXLEN) {
return FALSE; return FALSE;
} }
/* Validate that hostname has only ascii lowercase characters */
for (int i=0; i<hnlen; i++) { for (int i = 0; i < hnlen; i++) {
if (!( (hnaddr[i] >= '0' && hnaddr[i] <= '9') || if (!((hnaddr[i] >= '0' && hnaddr[i] <= '9') ||
(hnaddr[i] >= 'a' && hnaddr[i] <= 'z') || (hnaddr[i] >= 'a' && hnaddr[i] <= 'z') ||
hnaddr[i] == '.' || hnaddr[i] == '-')) hnaddr[i] == '.' || hnaddr[i] == '-'))
{ {
return FALSE; return FALSE;
} }
} }
*hostnameaddr = (char*)hnaddr; *hostnameaddr = (char*)hnaddr;
*hostnamelen = (unsigned int)hnlen; *hostnamelen = (unsigned int)hnlen;
return TRUE; return TRUE;
} }
ptr++; ptr++;
} }
return FALSE; return FALSE;
} }
static inline void change_window_size(const PWINDIVERT_TCPHDR ppTcpHdr, unsigned int size) { static inline void change_window_size(const PWINDIVERT_TCPHDR ppTcpHdr, unsigned int size) {
if (size >= 1 && size <= 0xFFFFu) { if (size >= 1 && size <= 0xFFFFu) {
ppTcpHdr->Window = htons((u_short)size); ppTcpHdr->Window = htons((u_short)size);
@ -441,118 +437,107 @@ static inline void change_window_size(const PWINDIVERT_TCPHDR ppTcpHdr, unsigned
/* HTTP method end without trailing space */ /* HTTP method end without trailing space */
static const char *find_http_method_end(const char *pkt, unsigned int http_frag, int *is_fragmented) { static const char *find_http_method_end(const char *pkt, unsigned int http_frag, int *is_fragmented) {
const char *method_end = NULL;
int fragmented = 0;
switch (*pkt) { switch (*pkt) {
case 'G': case 'G':
if (strncmp(pkt, "GET", 3) == 0) { if (strncmp(pkt, "GET", 3) == 0) {
if (is_fragmented) method_end = pkt + 3;
*is_fragmented = 0;
return pkt + 3;
} }
break; break;
case 'P': case 'P':
if (strncmp(pkt, "POST", 4) == 0) { if (strncmp(pkt, "POST", 4) == 0) {
if (is_fragmented) method_end = pkt + 4;
*is_fragmented = 0;
return pkt + 4;
} }
break; break;
case 'H': case 'H':
if (strncmp(pkt, "HEAD", 4) == 0) { if (strncmp(pkt, "HEAD", 4) == 0) {
if (is_fragmented) method_end = pkt + 4;
*is_fragmented = 0;
return pkt + 4;
} }
break; break;
case 'O': case 'O':
if (strncmp(pkt, "OPTIONS", 7) == 0) { if (strncmp(pkt, "OPTIONS", 7) == 0) {
if (is_fragmented) method_end = pkt + 7;
*is_fragmented = 0;
return pkt + 7;
} }
break; break;
case 'D': case 'D':
if (strncmp(pkt, "DELETE", 6) == 0) { if (strncmp(pkt, "DELETE", 6) == 0) {
if (is_fragmented) method_end = pkt + 6;
*is_fragmented = 0;
return pkt + 6;
} }
break; break;
case 'T': case 'T':
if (strncmp(pkt, "TRACE", 5) == 0) { if (strncmp(pkt, "TRACE", 5) == 0) {
if (is_fragmented) method_end = pkt + 5;
*is_fragmented = 0;
return pkt + 5;
} }
break; break;
case 'C': case 'C':
if (strncmp(pkt, "CONNECT", 7) == 0) { if (strncmp(pkt, "CONNECT", 7) == 0) {
if (is_fragmented) method_end = pkt + 7;
*is_fragmented = 0;
return pkt + 7;
} }
break; break;
default: default:
/* Try to find HTTP method in a second part of fragmented packet */ break;
if ((http_frag == 1 || http_frag == 2)) { }
if (method_end == NULL && (http_frag == 1 || http_frag == 2)) {
switch (*pkt) { switch (*pkt) {
case 'E': case 'E':
if (strncmp(pkt, "ET", http_frag) == 0) { if (strncmp(pkt, "ET", http_frag) == 0) {
if (is_fragmented) method_end = pkt + http_frag - 1;
*is_fragmented = 1; fragmented = 1;
return pkt + http_frag - 1;
} }
break; break;
case 'S': case 'S':
if (strncmp(pkt, "ST", http_frag) == 0) { if (strncmp(pkt, "ST", http_frag) == 0) {
if (is_fragmented) method_end = pkt + http_frag - 1;
*is_fragmented = 1; fragmented = 1;
return pkt + http_frag - 1;
} }
break; break;
case 'A': case 'A':
if (strncmp(pkt, "AD", http_frag) == 0) { if (strncmp(pkt, "AD", http_frag) == 0) {
if (is_fragmented) method_end = pkt + http_frag - 1;
*is_fragmented = 1; fragmented = 1;
return pkt + http_frag - 1;
} }
break; break;
case 'N': case 'N':
if (strncmp(pkt, "NS", http_frag) == 0) { if (strncmp(pkt, "NS", http_frag) == 0) {
if (is_fragmented) method_end = pkt + http_frag - 1;
*is_fragmented = 1; fragmented = 1;
return pkt + http_frag - 1;
} }
break; break;
case 'L': case 'L':
if (strncmp(pkt, "LE", http_frag) == 0) { if (strncmp(pkt, "LE", http_frag) == 0) {
if (is_fragmented) method_end = pkt + http_frag - 1;
*is_fragmented = 1; fragmented = 1;
return pkt + http_frag - 1;
} }
break; break;
case 'R': case 'R':
if (strncmp(pkt, "RACE", http_frag + 1) == 0) { if (strncmp(pkt, "RACE", http_frag + 1) == 0) {
if (is_fragmented) method_end = pkt + http_frag - 1;
*is_fragmented = 1; fragmented = 1;
return pkt + http_frag - 1;
} }
break; break;
case 'O': case 'O':
if (strncmp(pkt, "ONNECT", http_frag + 1) == 0) { if (strncmp(pkt, "ONNECT", http_frag + 1) == 0) {
if (is_fragmented) method_end = pkt + http_frag - 1;
*is_fragmented = 1; fragmented = 1;
return pkt + http_frag - 1;
} }
break; break;
default: default:
return NULL; break;
} }
} }
if (method_end != NULL && is_fragmented != NULL) {
*is_fragmented = fragmented;
} }
return NULL;
return method_end;
} }
/** Fragment and send the packet. /** Fragment and send the packet.
* *
* This function cuts off the end of the packet (step=0) or * This function cuts off the end of the packet (step=0) or
@ -575,8 +560,7 @@ static void send_native_fragment(HANDLE w_filter, WINDIVERT_ADDRESS addr,
return; return;
} }
switch(step) { if (step == 0) {
case 0:
if (packet_v4) if (packet_v4)
ppIpHdr->Length = htons( ppIpHdr->Length = htons(
ntohs(ppIpHdr->Length) - ntohs(ppIpHdr->Length) -
@ -588,8 +572,7 @@ static void send_native_fragment(HANDLE w_filter, WINDIVERT_ADDRESS addr,
packet_dataLen + fragment_size packet_dataLen + fragment_size
); );
packetLen = packetLen - packet_dataLen + fragment_size; packetLen = packetLen - packet_dataLen + fragment_size;
break; } else if (step == 1) {
case 1:
if (packet_v4) if (packet_v4)
ppIpHdr->Length = htons( ppIpHdr->Length = htons(
ntohs(ppIpHdr->Length) - fragment_size ntohs(ppIpHdr->Length) - fragment_size
@ -604,7 +587,6 @@ static void send_native_fragment(HANDLE w_filter, WINDIVERT_ADDRESS addr,
packetLen -= fragment_size; packetLen -= fragment_size;
ppTcpHdr->SeqNum = htonl(ntohl(ppTcpHdr->SeqNum) + fragment_size); ppTcpHdr->SeqNum = htonl(ntohl(ppTcpHdr->SeqNum) + fragment_size);
break;
} }
addr.IPChecksum = 0; addr.IPChecksum = 0;

Loading…
Cancel
Save