--- pppd/demand.c.orig 2004-11-04 11:02:26.000000000 +0100
+++ pppd/demand.c 2007-07-29 03:52:41.000000000 +0200
@@ -36,6 +36,8 @@
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
+#include <unistd.h>
+#include <syslog.h>
#include <sys/param.h>
#include <sys/types.h>
#include <sys/wait.h>
@@ -43,6 +45,8 @@
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
#ifdef PPP_FILTER
#include <pcap-bpf.h>
#endif
@@ -221,6 +225,14 @@
int c, rv;
rv = 0;
+
+/* check for synchronous connection... */
+
+ if ( (p[0] == 0xFF) && (p[1] == 0x03) ) {
+ rv = loop_frame(p,n);
+ return rv;
+ }
+
for (; n > 0; --n) {
c = *p++;
if (c == PPP_FLAG) {
@@ -299,17 +311,102 @@
* loopback, now that the real serial link is up.
*/
void
-demand_rexmit(proto)
+demand_rexmit(proto, newip)
int proto;
+ u_int32_t newip;
{
struct packet *pkt, *prev, *nextpkt;
+ unsigned short checksum;
+ unsigned short pkt_checksum = 0;
+ unsigned iphdr;
+ struct timeval tv;
+ char cv = 0;
+ char ipstr[16];
prev = NULL;
pkt = pend_q;
pend_q = NULL;
+ tv.tv_sec = 1;
+ tv.tv_usec = 0;
+ select(0,NULL,NULL,NULL,&tv); /* Sleep for 1 Seconds */
for (; pkt != NULL; pkt = nextpkt) {
nextpkt = pkt->next;
if (PPP_PROTOCOL(pkt->data) == proto) {
+ if ( (proto == PPP_IP) && newip ) {
+ /* Get old checksum */
+
+ iphdr = (pkt->data[4] & 15) << 2;
+ checksum = *((unsigned short *) (pkt->data+14));
+ if (checksum == 0xFFFF) {
+ checksum = 0;
+ }
+
+
+ if (pkt->data[13] == 17) {
+ pkt_checksum = *((unsigned short *) (pkt->data+10+iphdr));
+ if (pkt_checksum) {
+ cv = 1;
+ if (pkt_checksum == 0xFFFF) {
+ pkt_checksum = 0;
+ }
+ }
+ else {
+ cv = 0;
+ }
+ }
+
+ if (pkt->data[13] == 6) {
+ pkt_checksum = *((unsigned short *) (pkt->data+20+iphdr));
+ cv = 1;
+ if (pkt_checksum == 0xFFFF) {
+ pkt_checksum = 0;
+ }
+ }
+
+ /* Delete old Source-IP-Address */
+ checksum -= *((unsigned short *) (pkt->data+16)) ^ 0xFFFF;
+ checksum -= *((unsigned short *) (pkt->data+18)) ^ 0xFFFF;
+
+ pkt_checksum -= *((unsigned short *) (pkt->data+16)) ^ 0xFFFF;
+ pkt_checksum -= *((unsigned short *) (pkt->data+18)) ^ 0xFFFF;
+
+ /* Change Source-IP-Address */
+ * ((u_int32_t *) (pkt->data + 16)) = newip;
+
+ /* Add new Source-IP-Address */
+ checksum += *((unsigned short *) (pkt->data+16)) ^ 0xFFFF;
+ checksum += *((unsigned short *) (pkt->data+18)) ^ 0xFFFF;
+
+ pkt_checksum += *((unsigned short *) (pkt->data+16)) ^ 0xFFFF;
+ pkt_checksum += *((unsigned short *) (pkt->data+18)) ^ 0xFFFF;
+
+ /* Write new checksum */
+ if (!checksum) {
+ checksum = 0xFFFF;
+ }
+ *((unsigned short *) (pkt->data+14)) = checksum;
+ if (pkt->data[13] == 6) {
+ *((unsigned short *) (pkt->data+20+iphdr)) = pkt_checksum;
+ }
+ if (cv && (pkt->data[13] == 17) ) {
+ *((unsigned short *) (pkt->data+10+iphdr)) = pkt_checksum;
+ }
+
+ /* Log Packet */
+ strcpy(ipstr,inet_ntoa(*( (struct in_addr *) (pkt->data+16))));
+ if (pkt->data[13] == 1) {
+ syslog(LOG_INFO,"Open ICMP %s -> %s\n",
+ ipstr,
+ inet_ntoa(*( (struct in_addr *) (pkt->data+20))));
+ } else {
+ syslog(LOG_INFO,"Open %s %s:%d -> %s:%d\n",
+ pkt->data[13] == 6 ? "TCP" : "UDP",
+ ipstr,
+ ntohs(*( (short *) (pkt->data+iphdr+4))),
+ inet_ntoa(*( (struct in_addr *) (pkt->data+20))),
+ ntohs(*( (short *) (pkt->data+iphdr+6))));
+ }
+ }
output(0, pkt->data, pkt->length);
free(pkt);
} else {
--- pppd/ipcp.c.orig 2007-07-29 03:52:41.000000000 +0200
+++ pppd/ipcp.c 2007-07-29 03:52:41.000000000 +0200
@@ -1796,7 +1796,7 @@
proxy_arp_set[f->unit] = 1;
}
- demand_rexmit(PPP_IP);
+ demand_rexmit(PPP_IP,go->ouraddr);
sifnpmode(f->unit, PPP_IP, NPMODE_PASS);
} else {
--- pppd/ipv6cp.c.orig 2004-11-13 03:28:15.000000000 +0100
+++ pppd/ipv6cp.c 2007-07-29 03:52:41.000000000 +0200
@@ -1232,7 +1232,7 @@
}
}
- demand_rexmit(PPP_IPV6);
+ demand_rexmit(PPP_IPV6,0);
sifnpmode(f->unit, PPP_IPV6, NPMODE_PASS);
} else {
--- pppd/pppd.h.orig 2007-07-29 03:52:41.000000000 +0200
+++ pppd/pppd.h 2007-07-29 03:52:41.000000000 +0200
@@ -563,7 +563,7 @@
void demand_block __P((void)); /* set all NPs to queue up packets */
void demand_unblock __P((void)); /* set all NPs to pass packets */
void demand_discard __P((void)); /* set all NPs to discard packets */
-void demand_rexmit __P((int)); /* retransmit saved frames for an NP */
+void demand_rexmit __P((int, u_int32_t)); /* retransmit saved frames for an NP*/
int loop_chars __P((unsigned char *, int)); /* process chars from loopback */
int loop_frame __P((unsigned char *, int)); /* should we bring link up? */