Dave Barach
b7b929931a
Change-Id: Ied34720ca5a6e6e717eea4e86003e854031b6eab Signed-off-by: Dave Barach <dave@barachs.net>
110 lines
2.4 KiB
C
110 lines
2.4 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <string.h>
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#include <netinet/in.h>
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#include <netinet/ip.h>
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#include <netinet/ip_icmp.h>
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#include <arpa/inet.h>
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#include <net/if.h>
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#include <stdbool.h>
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#include <errno.h>
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static void
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usage (void) {
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fprintf(stderr,
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"Usage: health_check"
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" -d debug"
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" -I interface"
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"\n");
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exit(2);
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}
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int
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main (int argc, char **argv)
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{
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int sd, ch;
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uint8_t *opt, *pkt;
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struct ifreq ifr;
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char *interface = NULL;
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bool debug = false;
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while ((ch = getopt(argc, argv, "h?" "I:" "d")) != EOF) {
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switch(ch) {
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case 'I':
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interface = optarg;
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break;
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case 'd':
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debug = true;
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break;
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default:
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usage();
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break;
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}
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}
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argc -= optind;
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argv += optind;
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if (!interface)
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usage();
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/* Request a socket descriptor sd. */
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if ((sd = socket (AF_INET6, SOCK_RAW, IPPROTO_IPIP)) < 0) {
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perror ("Failed to get socket descriptor ");
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exit (EXIT_FAILURE);
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}
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clib_memset(&ifr, 0, sizeof(ifr));
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snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s", interface);
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/* Bind socket to interface of this node. */
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if (setsockopt (sd, SOL_SOCKET, SO_BINDTODEVICE, (void *) &ifr, sizeof (ifr)) < 0) {
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perror ("SO_BINDTODEVICE failed");
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exit (EXIT_FAILURE);
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}
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if (debug) printf("Binding to interface %s\n", interface);
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while (1) {
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struct sockaddr_in6 src_addr;
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socklen_t addrlen = sizeof(src_addr);
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char source[INET6_ADDRSTRLEN+1];
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int len;
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uint8_t inpack[IP_MAXPACKET];
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if ((len = recvfrom(sd, inpack, sizeof(inpack), 0, (struct sockaddr *)&src_addr, &addrlen)) < 0) {
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perror("recvfrom failed ");
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}
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if (inet_ntop(AF_INET6, &src_addr.sin6_addr, source, INET6_ADDRSTRLEN) == NULL) {
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perror("inet_ntop() failed.");
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exit(EXIT_FAILURE);
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}
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/* Reply */
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struct iphdr *ip = (struct iphdr *)inpack;
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uint32_t saddr;
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struct icmphdr *icmp;
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saddr = ip->saddr;
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ip->saddr = ip->daddr;
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ip->daddr = saddr;
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switch (ip->protocol) {
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case 1:
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if (debug) printf ("ICMP Echo request from %s\n", source);
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icmp = (struct icmphdr *)&ip[1];
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icmp->type = ICMP_ECHOREPLY;
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break;
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default:
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fprintf(stderr, "Unsupported protocol %d", ip->protocol);
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}
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if (len = sendto(sd, inpack, len, 0, (struct sockaddr *)&src_addr, addrlen) < 0) {
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perror("sendto failed ");
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}
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}
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close (sd);
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return (EXIT_SUCCESS);
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}
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