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-rw-r--r--src/plugins/examples/health_check.c109
1 files changed, 109 insertions, 0 deletions
diff --git a/src/plugins/examples/health_check.c b/src/plugins/examples/health_check.c
new file mode 100644
index 00000000000..5f0d85fec08
--- /dev/null
+++ b/src/plugins/examples/health_check.c
@@ -0,0 +1,109 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <netinet/in.h>
+#include <netinet/ip.h>
+#include <netinet/ip_icmp.h>
+#include <arpa/inet.h>
+#include <net/if.h>
+#include <stdbool.h>
+#include <errno.h>
+
+static void
+usage (void) {
+ fprintf(stderr,
+ "Usage: health_check"
+ " -d debug"
+ " -I interface"
+ "\n");
+ exit(2);
+}
+
+int
+main (int argc, char **argv)
+{
+ int sd, ch;
+ uint8_t *opt, *pkt;
+ struct ifreq ifr;
+ char *interface = NULL;
+ bool debug = false;
+
+ while ((ch = getopt(argc, argv, "h?" "I:" "d")) != EOF) {
+ switch(ch) {
+ case 'I':
+ interface = optarg;
+ break;
+ case 'd':
+ debug = true;
+ break;
+ default:
+ usage();
+ break;
+ }
+ }
+
+ argc -= optind;
+ argv += optind;
+
+ if (!interface)
+ usage();
+
+ /* Request a socket descriptor sd. */
+ if ((sd = socket (AF_INET6, SOCK_RAW, IPPROTO_IPIP)) < 0) {
+ perror ("Failed to get socket descriptor ");
+ exit (EXIT_FAILURE);
+ }
+
+ memset(&ifr, 0, sizeof(ifr));
+ snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s", interface);
+
+ /* Bind socket to interface of this node. */
+ if (setsockopt (sd, SOL_SOCKET, SO_BINDTODEVICE, (void *) &ifr, sizeof (ifr)) < 0) {
+ perror ("SO_BINDTODEVICE failed");
+ exit (EXIT_FAILURE);
+ }
+ if (debug) printf("Binding to interface %s\n", interface);
+
+ while (1) {
+ struct sockaddr_in6 src_addr;
+ socklen_t addrlen = sizeof(src_addr);
+ char source[INET6_ADDRSTRLEN+1];
+ int len;
+ uint8_t inpack[IP_MAXPACKET];
+
+ if ((len = recvfrom(sd, inpack, sizeof(inpack), 0, (struct sockaddr *)&src_addr, &addrlen)) < 0) {
+ perror("recvfrom failed ");
+ }
+ if (inet_ntop(AF_INET6, &src_addr.sin6_addr, source, INET6_ADDRSTRLEN) == NULL) {
+ perror("inet_ntop() failed.");
+ exit(EXIT_FAILURE);
+ }
+
+ /* Reply */
+ struct iphdr *ip = (struct iphdr *)inpack;
+ uint32_t saddr;
+ struct icmphdr *icmp;
+
+ saddr = ip->saddr;
+ ip->saddr = ip->daddr;
+ ip->daddr = saddr;
+
+ switch (ip->protocol) {
+ case 1:
+ if (debug) printf ("ICMP Echo request from %s\n", source);
+ icmp = (struct icmphdr *)&ip[1];
+ icmp->type = ICMP_ECHOREPLY;
+ break;
+ default:
+ fprintf(stderr, "Unsupported protocol %d", ip->protocol);
+ }
+ if (len = sendto(sd, inpack, len, 0, (struct sockaddr *)&src_addr, addrlen) < 0) {
+ perror("sendto failed ");
+ }
+ }
+
+ close (sd);
+
+ return (EXIT_SUCCESS);
+}