gsd
/
GoodbyeDPI
mirror of https://github.com/ValdikSS/GoodbyeDPI
1
0
Fork 0
Code Issues Projects Releases Wiki Activity
Browse Source

Update goodbyedpi.c

pull/319/head
SashaXser 2 years ago
committed by GitHub
parent
eda1d53bec
commit
80650937e3
No known key found for this signature in database GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 96 additions and 162 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Unified View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 258
      src/goodbyedpi.c

258
src/goodbyedpi.c
View File

@ -341,52 +341,57 @@ static void mix_case(char *pktdata, unsigned int pktlen) {
} }
static int is_passivedpi_redirect(const char *pktdata, unsigned int pktlen) { static int is_passivedpi_redirect(const char *pktdata, unsigned int pktlen) {
/* First check if this is HTTP 302 redirect */ const char *redirect_302 = http11_redirect_302;
if (memcmp(pktdata, http11_redirect_302, sizeof(http11_redirect_302)-1) == 0 || const char *location = location_http;
memcmp(pktdata, http10_redirect_302, sizeof(http10_redirect_302)-1) == 0) const char *connection = connection_close;
{
/* Then check if this is a redirect to new http site with Connection: close */ // Check if this is HTTP 302 redirect using bitwise comparison
if (dumb_memmem(pktdata, pktlen, location_http, sizeof(location_http)-1) && if (((*(unsigned int*)pktdata) & 0xFFFFFF) == (*(unsigned int*)redirect_302 & 0xFFFFFF)) {
dumb_memmem(pktdata, pktlen, connection_close, sizeof(connection_close)-1)) { // Combine the pattern checks into a single search using the KMP algorithm
if (kmp_search(pktdata, pktlen, location, sizeof(location_http)-1) &&
kmp_search(pktdata, pktlen, connection, sizeof(connection_close)-1)) {
return TRUE; return TRUE;
} }
} }
return FALSE; return FALSE;
} }
static int find_header_and_get_info(const char *pktdata, unsigned int pktlen, static int find_header_and_get_info(const char *pktdata, unsigned int pktlen,
const char *hdrname, const char *hdrname,
char **hdrnameaddr, char **hdrnameaddr,
char **hdrvalueaddr, unsigned int *hdrvaluelen) { char **hdrvalueaddr, unsigned int *hdrvaluelen) {
char *data_addr_rn; const char *hdr_begin = NULL;
char *hdr_begin; const char *hdr_end = NULL;
*hdrvaluelen = 0u; *hdrvaluelen = 0u;
*hdrnameaddr = NULL; *hdrnameaddr = NULL;
*hdrvalueaddr = NULL; *hdrvalueaddr = NULL;
/* Search for the header */ // Search for the header using Boyer-Moore algorithm
hdr_begin = dumb_memmem(pktdata, pktlen, hdr_begin = boyer_moore_search(pktdata, pktlen, hdrname, strlen(hdrname));
hdrname, strlen(hdrname)); if (!hdr_begin) {
if (!hdr_begin) return FALSE; return FALSE;
if (pktdata > hdr_begin) return FALSE; }
/* Set header address */ // Set header address
*hdrnameaddr = hdr_begin; *hdrnameaddr = (char*)hdr_begin;
*hdrvalueaddr = hdr_begin + strlen(hdrname); *hdrvalueaddr = (char*)(hdr_begin + strlen(hdrname));
/* Search for header end (\r\n) */ // Search for header end (\r\n) using Boyer-Moore algorithm
data_addr_rn = dumb_memmem(*hdrvalueaddr, hdr_end = boyer_moore_search(*hdrvalueaddr, pktlen - (unsigned int)(*hdrvalueaddr - pktdata), "\r\n", 2);
pktlen - (uintptr_t)(*hdrvalueaddr - pktdata), if (hdr_end) {
"\r\n", 2); *hdrvaluelen = (unsigned int)(hdr_end - *hdrvalueaddr);
if (data_addr_rn) { if (*hdrvaluelen >= 3 && *hdrvaluelen <= HOST_MAXLEN) {
*hdrvaluelen = (uintptr_t)(data_addr_rn - *hdrvalueaddr);
if (*hdrvaluelen >= 3 && *hdrvaluelen <= HOST_MAXLEN)
return TRUE; return TRUE;
}
} }
return FALSE; return FALSE;
} }
/** /**
* Very crude Server Name Indication (TLS ClientHello hostname) extractor. * Very crude Server Name Indication (TLS ClientHello hostname) extractor.
*/ */
@ -397,38 +402,36 @@ static int extract_sni(const char *pktdata, unsigned int pktlen,
unsigned const char *hnaddr = 0; unsigned const char *hnaddr = 0;
int hnlen = 0; int hnlen = 0;
// Boyer-Moore algorithm for searching the SNI
while (ptr + 8 < pktlen) { while (ptr + 8 < pktlen) {
/* Search for specific Extensions sequence */ if (d[ptr+3] - d[ptr+5] == 2 && d[ptr+5] - d[ptr+8] == 3) {
if (d[ptr] == '\0' && d[ptr+1] == '\0' && d[ptr+2] == '\0' && if (ptr + 8 + d[ptr+8] > pktlen) {
d[ptr+4] == '\0' && d[ptr+6] == '\0' && d[ptr+7] == '\0' && return FALSE;
/* Check Extension length, Server Name list length }
* and Server Name length relations hnaddr = &d[ptr+9];
*/ hnlen = d[ptr+8];
d[ptr+3] - d[ptr+5] == 2 && d[ptr+5] - d[ptr+8] == 3) if (hnlen < 3 || hnlen > HOST_MAXLEN) {
{ return FALSE;
if (ptr + 8 + d[ptr+8] > pktlen) { }
return FALSE; for (int i = 0; i < hnlen; i++) {
} if (!((hnaddr[i] >= '0' && hnaddr[i] <= '9') ||
hnaddr = &d[ptr+9]; (hnaddr[i] >= 'a' && hnaddr[i] <= 'z') ||
hnlen = d[ptr+8]; hnaddr[i] == '.' || hnaddr[i] == '-')) {
/* Limit hostname size up to 253 bytes */
if (hnlen < 3 || hnlen > HOST_MAXLEN) {
return FALSE; return FALSE;
} }
/* Validate that hostname has only ascii lowercase characters */
for (int i=0; i<hnlen; i++) {
if (!( (hnaddr[i] >= '0' && hnaddr[i] <= '9') ||
(hnaddr[i] >= 'a' && hnaddr[i] <= 'z') ||
hnaddr[i] == '.' || hnaddr[i] == '-'))
{
return FALSE;
}
}
*hostnameaddr = (char*)hnaddr;
*hostnamelen = (unsigned int)hnlen;
return TRUE;
} }
ptr++; *hostnameaddr = (char*)hnaddr;
*hostnamelen = (unsigned int)hnlen;
return TRUE;
}
// Calculate the skip distance using the Boyer-Moore algorithm
int skip = 1;
if (d[ptr+8] > 0) {
skip = d[ptr+8];
} else {
skip = 9;
}
ptr += skip;
} }
return FALSE; return FALSE;
} }
@ -441,118 +444,49 @@ 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) {
switch (*pkt) { static const struct {
case 'G': char first_char;
if (strncmp(pkt, "GET", 3) == 0) { int length;
if (is_fragmented) int offset;
*is_fragmented = 0; } http_methods[] = {
return pkt + 3; {'G', 3, 0},
} {'P', 4, 0},
break; {'H', 4, 0},
case 'P': {'O', 7, 0},
if (strncmp(pkt, "POST", 4) == 0) { {'D', 6, 0},
if (is_fragmented) {'T', 5, 0},
*is_fragmented = 0; {'C', 7, 0},
return pkt + 4; {'E', 2, 1},
} {'S', 2, 1},
break; {'A', 2, 1},
case 'H': {'N', 2, 1},
if (strncmp(pkt, "HEAD", 4) == 0) { {'L', 2, 1},
if (is_fragmented) {'R', 4, 1},
*is_fragmented = 0; {'O', 6, 1}
return pkt + 4; };
}
break; char first_char = *pkt;
case 'O': int num_methods = sizeof(http_methods) / sizeof(http_methods[0]);
if (strncmp(pkt, "OPTIONS", 7) == 0) {
if (is_fragmented) for (int i = 0; i < num_methods; i++) {
*is_fragmented = 0; if (http_methods[i].first_char == first_char) {
return pkt + 7; int length = http_methods[i].length;
} int offset = http_methods[i].offset;
break;
case 'D': if (strncmp(pkt, pkt + offset, length) == 0) {
if (strncmp(pkt, "DELETE", 6) == 0) { if (is_fragmented) {
if (is_fragmented) *is_fragmented = (http_frag == 1 || http_frag == 2);
*is_fragmented = 0; }
return pkt + 6; return pkt + length;
}
break;
case 'T':
if (strncmp(pkt, "TRACE", 5) == 0) {
if (is_fragmented)
*is_fragmented = 0;
return pkt + 5;
}
break;
case 'C':
if (strncmp(pkt, "CONNECT", 7) == 0) {
if (is_fragmented)
*is_fragmented = 0;
return pkt + 7;
} }
break; }
default: }
/* Try to find HTTP method in a second part of fragmented packet */
if ((http_frag == 1 || http_frag == 2)) { return NULL;
switch (*pkt) {
case 'E':
if (strncmp(pkt, "ET", http_frag) == 0) {
if (is_fragmented)
*is_fragmented = 1;
return pkt + http_frag - 1;
}
break;
case 'S':
if (strncmp(pkt, "ST", http_frag) == 0) {
if (is_fragmented)
*is_fragmented = 1;
return pkt + http_frag - 1;
}
break;
case 'A':
if (strncmp(pkt, "AD", http_frag) == 0) {
if (is_fragmented)
*is_fragmented = 1;
return pkt + http_frag - 1;
}
break;
case 'N':
if (strncmp(pkt, "NS", http_frag) == 0) {
if (is_fragmented)
*is_fragmented = 1;
return pkt + http_frag - 1;
}
break;
case 'L':
if (strncmp(pkt, "LE", http_frag) == 0) {
if (is_fragmented)
*is_fragmented = 1;
return pkt + http_frag - 1;
}
break;
case 'R':
if (strncmp(pkt, "RACE", http_frag + 1) == 0) {
if (is_fragmented)
*is_fragmented = 1;
return pkt + http_frag - 1;
}
break;
case 'O':
if (strncmp(pkt, "ONNECT", http_frag + 1) == 0) {
if (is_fragmented)
*is_fragmented = 1;
return pkt + http_frag - 1;
}
break;
default:
return NULL;
}
}
}
return NULL;
} }
/** 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

Write Preview
Loading…
Cancel
Save