marvin.weiler/python-netfilterqueue
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work on new packet

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dowright 2021-08-25 15:45:04 -07:00 committed by DOWRIGHT
parent 57097b3371
commit 1c602981f0
2 changed files with 26 additions and 12 deletions
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4
new_packet.pxd
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@ -14,7 +14,7 @@ cdef enum:
# cython define
cdef struct iphdr:
u_int8_t ihl_ver
u_int8_t ver_ihl
u_int8_t tos
u_int16_t tot_len
u_int16_t id
@ -32,7 +32,7 @@ cdef struct tcphdr:
u_int32_t th_seq
u_int32_t th_ack
u_int8_t th_off
u_int8_t th_off
u_int8_t th_flags
u_int16_t th_win

34
new_packet.pyx
View File

@ -77,32 +77,46 @@ cdef class CPacket:
self.ip_header = <iphdr*>self.data
cdef u_int8_t iphdr_len = (self.ip_header.tos & 15) * 4
cdef u_int8_t hdr_shift = 4
cdef u_int8_t hdr_multiplier = 4
cdef u_int8_t hdr_xand = 15
cdef u_int8_t iphdr_len
iphdr_len = self.ip_header.ver_ihl & hdr_xand
iphdr_len = iphdr_len * hdr_multiplier
printf('ip header length=%f\n', iphdr_len)
cdef u_int8_t tcphdr_len
cdef u_int8_t udphdr_len
cdef u_int8_t udphdr_len = 8
cdef u_int8_t icmphdr_len = 4
cdef void *data = &self.data[iphdr_len]
cdef ptrdiff_t hdrptr = <u_int32_t*>data - <u_int32_t*>self.data
if (self.ip_header.protocol == IPPROTO_TCP):
self.tcp_header = <tcphdr*>data
self.tcp_header = <tcphdr*>&hdrptr
tcphdr_len = (self.tcp_header.th_off & 15) * 4
tcphdr_len = self.tcp_header.th_off >> hdr_shift
tcphdr_len = tcphdr_len & hdr_xand
tcphdr_len = tcphdr_len * hdr_multiplier
printf('TCP HEADER LEN=%f\n', tcphdr_len)
self.cmbhdr_len = iphdr_len + tcphdr_len
elif (self.ip_header.protocol == IPPROTO_UDP):
self.udp_header = <udphdr*>data
udphdr_len = 8
self.udp_header = <udphdr*>&hdrptr
self.cmbhdr_len = iphdr_len + udphdr_len
elif (self.ip_header.protocol == IPPROTO_ICMP):
self.icmp_header = <icmphdr*>data
self.icmp_header = <icmphdr*>&hdrptr
self.cmbhdr_len = iphdr_len + icmphdr_len
cdef void verdict(self, u_int32_t verdict):
'''Call appropriate set_verdict function on packet.'''
@ -245,7 +259,7 @@ cdef class CPacket:
cdef tuple ip_header
ip_header = (
self.ip_header.ihl_ver,
self.ip_header.ver_ihl,
self.ip_header.tos,
ntohs(self.ip_header.tot_len),
ntohs(self.ip_header.id),
@ -305,7 +319,7 @@ cdef class CPacket:
cdef object payload
payload = self.data[self.cmbhdr_len:self.data_len]
payload = self.data[<Py_ssize_t>self.cmbhdr_len:self.data_len]
return payload