Hello, Sam And Linux-Net-izens....
I have a question about IPIP + SOCK_PACKET....
I want to process all of IP-in-IP Encapsulated packet
outgoing as well as incoming
....
I used SOCK_PACKET and recvfrom() ....
partial source codes are below ....
I succeeded in getting all of outgoing IP-in-IP packet
....
But I could not get any incoming IP-in-IP
packet ....
Does IPIP module decapsulate incoming IP-in-IP packet
before recvfrom() by SOCK_PACKET
?
If IPIP does act as above, how can I get incoming IP-in-IP
packet ?
Any comments are really appreciated ....
Thanks in advance ....
================================================================
cf. data->buf[12] = 8;
data->buf[13] = 0; /*
0x80 IP Packet type (Ethernet Frame)
*/
data->buf[23] = 4; /*
IPPROTO_IPIP */
================================================================
/* Partial Source Code */
unsigned char
buf[MAXDLBUF];
struct strbuf data;
struct strbuf data;
/* struct strbuf
{
int len;
char *buf;
int maxlen;
}
*/
int flags;
int i, fd, maxfd;
fd_set fdvec;
struct timeval tv;
struct sockaddr from;
int fromlen, len;
int flags;
int i, fd, maxfd;
fd_set fdvec;
struct timeval tv;
struct sockaddr from;
int fromlen, len;
if ((fd = socket(AF_INET, SOCK_PACKET, htons(ETH_P_ALL))) <
0) {
printf("Error_in_opening_SOCK_PACKET_socket_for_agent_adv_..\n");
exit(-1);
}
data.buf = (char *) buf;
data.maxlen = MAXDLBUF;
/* Read packets.*/
while (1) {
tv.tv_sec = 0;
tv.tv_usec = 0;
FD_ZERO(&fdvec);
FD_SET(fd, &fdvec);
maxfd = fd+1;
if ((i = select(maxfd, &fdvec, NULL, NULL, &tv)) < 0) {
if ((errno != EINTR) && (errno != ERESTART)) {
printf("select_failed_but_not_due_to_EINTR_or_ERESTART_\n");
printf("Error_in_opening_SOCK_PACKET_socket_for_agent_adv_..\n");
exit(-1);
}
data.buf = (char *) buf;
data.maxlen = MAXDLBUF;
/* Read packets.*/
while (1) {
tv.tv_sec = 0;
tv.tv_usec = 0;
FD_ZERO(&fdvec);
FD_SET(fd, &fdvec);
maxfd = fd+1;
if ((i = select(maxfd, &fdvec, NULL, NULL, &tv)) < 0) {
if ((errno != EINTR) && (errno != ERESTART)) {
printf("select_failed_but_not_due_to_EINTR_or_ERESTART_\n");
} else
{
printf("select_failed_due_to_EINTR_or_ERESTART\n");
}
} else if (FD_ISSET(fd, &fdvec)) {
data.len = MAXDLBUF;
fromlen = sizeof(struct sockaddr);
do {
len = recvfrom(fd, buf, data.len, 0, &from, &fromlen);
} while ((len < 0) && (errno == EINTR));
if (len < 0) {
printf("Recvfrom_failed_in_monitor()\n");
} else {
data.len = len;
printf("select_failed_due_to_EINTR_or_ERESTART\n");
}
} else if (FD_ISSET(fd, &fdvec)) {
data.len = MAXDLBUF;
fromlen = sizeof(struct sockaddr);
do {
len = recvfrom(fd, buf, data.len, 0, &from, &fromlen);
} while ((len < 0) && (errno == EINTR));
if (len < 0) {
printf("Recvfrom_failed_in_monitor()\n");
} else {
data.len = len;
blah~
blah~
blah~
-------------------------------------
Park, Hyun Seo
Graduate Student
Department of Computer Engineering, Chungnam National University
220 Gung-dong,YuSeong-Gu, Taejon, 305764, Korea
E-mail: hspark@ce.cnu.ac.kr
ICQ # : 28055093
Phone : +82-42-823-6049
-------------------------------------
Park, Hyun Seo
Graduate Student
Department of Computer Engineering, Chungnam National University
220 Gung-dong,YuSeong-Gu, Taejon, 305764, Korea
E-mail: hspark@ce.cnu.ac.kr
ICQ # : 28055093
Phone : +82-42-823-6049
