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gatppp: Refactor rx path

This commit is contained in:
Denis Kenzior 2011-06-29 03:32:51 -05:00
parent 12338faabd
commit bc37c74653
2 changed files with 32 additions and 33 deletions
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54
gatchat/gatppp.c
View File

@ -170,38 +170,48 @@ static inline gboolean ppp_drop_packet(GAtPPP *ppp, guint16 protocol)
static void ppp_receive(const unsigned char *buf, gsize len, void *data)
{
GAtPPP *ppp = data;
struct ppp_header *header = (struct ppp_header *) buf;
gboolean acfc_frame = (header->address != PPP_ADDR_FIELD
|| header->control != PPP_CTRL);
gboolean pfc_frame = FALSE;
unsigned int offset = 0;
guint16 protocol;
const guint8 *packet;
if (acfc_frame) {
protocol = ppp_acfc_proto(buf);
packet = ppp_acfc_info(buf);
if (len == 0)
return;
if (buf[0] == PPP_ADDR_FIELD && len >= 2 && buf[1] == PPP_CTRL)
offset = 2;
if (len < offset + 1)
return;
/* From RFC 1661:
* the Protocol field uses an extension mechanism consistent with the
* ISO 3309 extension mechanism for the Address field; the Least
* Significant Bit (LSB) of each octet is used to indicate extension
* of the Protocol field. A binary "0" as the LSB indicates that the
* Protocol field continues with the following octet. The presence
* of a binary "1" as the LSB marks the last octet of the Protocol
* field.
*
* To check for compression we simply check the LSB of the first
* protocol byte.
*/
if (buf[offset] & 0x1) {
protocol = buf[offset];
offset += 1;
} else {
protocol = ppp_proto(buf);
packet = ppp_info(buf);
}
if (len < offset + 2)
return;
pfc_frame = (protocol != LCP_PROTOCOL && protocol != CHAP_PROTOCOL &&
protocol != IPCP_PROTO && protocol != PPP_IP_PROTO);
if (pfc_frame) {
guint8 proto = (protocol >> 8) & 0xFF ;
packet = packet - 1;
/*
* The only protocol that can be compressed is PPP_IP_PROTO
* because first byte is 0x00.
*/
if (proto == PPP_IP_COMPRESSED_PROTO)
protocol = PPP_IP_PROTO;
protocol = get_host_short(buf + offset);
offset += 2;
}
if (ppp_drop_packet(ppp, protocol))
return;
packet = buf + offset;
switch (protocol) {
case PPP_IP_PROTO:
ppp_net_process_packet(ppp->net, packet);

11
gatchat/ppp.h
View File

@ -27,8 +27,6 @@
#define PPP_IP_PROTO 0x0021
#define MD5 5
#define PPP_IP_COMPRESSED_PROTO 0x21
#define DBG(p, fmt, arg...) do { \
char *str = g_strdup_printf("%s:%s() " fmt, __FILE__, \
__FUNCTION__ , ## arg); \
@ -81,18 +79,9 @@ static inline void __put_unaligned_short(void *p, guint16 val)
#define put_network_short(p, val) \
(__put_unaligned_short(p, htons(val)))
#define ppp_info(packet) \
(packet + 4)
#define ppp_proto(packet) \
(get_host_short(packet + 2))
#define ppp_acfc_info(packet) \
(packet + 2)
#define ppp_acfc_proto(packet) \
(get_host_short(packet))
/* LCP related functions */
struct pppcp_data *lcp_new(GAtPPP *ppp, gboolean dormant);
void lcp_free(struct pppcp_data *lcp);