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osmo-bsc
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Readd the dummy lapd header... this gives valid TEI/SAPI information 

Besides that the header is spoofed, we lose the information about
the channel (we will have to add our own encap type)
This commit is contained in:
Harald Welte 2009-01-03 03:28:10 +00:00
parent 4e0d137a2c
commit 599639eaf9
1 changed files with 22 additions and 2 deletions
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24
src/misdn.c
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@ -82,6 +82,15 @@ struct fake_linux_lapd_header {
int16_t protocol;
} __attribute__((packed));
struct lapd_header {
u_int8_t ea1 : 1;
u_int8_t cr : 1;
u_int8_t sapi : 6;
u_int8_t ea2 : 1;
u_int8_t tei : 7;
u_int8_t control_foo; /* fake UM's ... */
} __attribute__((packed));
static_assert((int)&((struct fake_linux_lapd_header*)NULL)->hatype == 2, hatype_offset);
static_assert((int)&((struct fake_linux_lapd_header*)NULL)->halen == 4, halen_offset);
static_assert((int)&((struct fake_linux_lapd_header*)NULL)->addr == 6, addr_offset);
@ -122,17 +131,27 @@ static void write_pcap_packet(int direction, struct sockaddr_mISDN* addr,
.pkttype = 4,
.hatype = 0,
.halen = 0,
.addr = 0x1,
.addr = direction == PCAP_OUTPUT ? 0x0 : 0x1,
.protocol = ntohs(48),
};
struct lapd_header lapd_header = {
.ea1 = 0,
.cr = direction == PCAP_OUTPUT ? 1 : 0,
.sapi = addr->sapi & 0x3F,
.ea2 = 1,
.tei = addr->tei & 0x7F,
.control_foo = 0x13 /* UI with P set */,
};
struct pcaprec_hdr payload_header = {
.ts_sec = 0,
.ts_usec = 0,
.incl_len = msg->len + sizeof(struct fake_linux_lapd_header)
+ sizeof(struct lapd_header)
- MISDN_HEADER_LEN,
.orig_len = msg->len + sizeof(struct fake_linux_lapd_header)
+ sizeof(struct lapd_header)
- MISDN_HEADER_LEN,
};
@ -143,6 +162,7 @@ static void write_pcap_packet(int direction, struct sockaddr_mISDN* addr,
ret = write(pcap_fd, &payload_header, sizeof(payload_header));
ret = write(pcap_fd, &header, sizeof(header));
ret = write(pcap_fd, &lapd_header, sizeof(lapd_header));
ret = write(pcap_fd, msg->data + MISDN_HEADER_LEN,
msg->len - MISDN_HEADER_LEN);
}