pingu_ping: initial implementation

1 files changed, 133 insertions, 0 deletions

diff --git a/pingu_ping.c b/pingu_ping.c
new file mode 100644
index 0000000..c6ac66d
--- /dev/null
+++ b/pingu_ping.c
@@ -0,0 +1,133 @@
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <netinet/ip.h>
+#include <netinet/ip_icmp.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <ev.h>
+
+#include "icmp.h"
+#include "list.h"
+#include "log.h"
+#include "pingu_burst.h"
+#include "pingu_host.h"
+#include "pingu_iface.h"
+#include "pingu_ping.h"
+
+#define SOCK_ADDR_IN_PTR(sa)	((struct sockaddr_in *)(sa))
+#define SOCK_ADDR_IN_ADDR(sa)	SOCK_ADDR_IN_PTR(sa)->sin_addr
+
+#define PING_SEQ_MAX 32000
+
+static int pingu_ping_get_seq(void)
+{
+	static int seq = 0;
+	seq = (seq + 1) % PING_SEQ_MAX;
+	return seq;
+}
+
+static void pingu_ping_timeout_cb(struct ev_loop *loop, ev_timer *w,
+				  int revents)
+{
+	struct pingu_ping *ping = container_of(w, struct pingu_ping, timeout_watcher);
+	log_debug("%s: seq %i timed out", ping->host->host, ping->seq);
+	list_del(&ping->ping_list_entry);
+	pingu_host_verify_status(loop, ping->host);
+	free(ping);
+}
+
+static struct pingu_ping *pingu_ping_add(struct ev_loop *loop,
+					 struct pingu_host *host, int seq)
+{
+	struct pingu_ping *ping = calloc(1, sizeof(struct pingu_ping));
+	if (ping == NULL)
+		return NULL;
+	ping->seq = seq;
+	ping->host = host;
+	ev_timer_init(&ping->timeout_watcher, pingu_ping_timeout_cb,
+		      host->timeout, 0);
+	ev_timer_start(loop, &ping->timeout_watcher);
+	list_add(&ping->ping_list_entry, &host->iface->ping_list);
+	return ping;
+}
+
+static int sockaddr_cmp(struct sockaddr *a, struct sockaddr *b)
+{
+	if (a->sa_family != b->sa_family)
+		return -1;
+	switch (a->sa_family) {
+	case AF_INET:
+		return (SOCK_ADDR_IN_ADDR(a).s_addr - SOCK_ADDR_IN_ADDR(b).s_addr);
+		break;
+	}
+	return -1;
+}
+
+static struct pingu_ping *pingu_ping_find(struct icmphdr *icp,
+					  struct sockaddr *from,
+					  struct list_head *ping_list)
+{
+	struct pingu_ping *ping;
+	if (icp->type != ICMP_ECHOREPLY || icp->un.echo.id != getpid())
+		return NULL;
+	
+	list_for_each_entry(ping, ping_list, ping_list_entry) {
+		if (sockaddr_cmp(&ping->host->burst.saddr, from) == 0
+		    && ping->seq == ntohs(icp->un.echo.sequence))
+			return ping;
+	}
+	return NULL;
+}
+
+static void pingu_ping_handle_reply(struct ev_loop *loop,
+				    struct pingu_ping *ping)
+{
+	log_debug("%s: got seq %i", ping->host->host, ping->seq);
+	ping->host->burst.pings_replied++;
+	list_del(&ping->ping_list_entry);
+	ev_timer_stop(&ping->timeout_watcher, loop);
+	pingu_host_verify_status(loop, ping->host);
+	free(ping);
+}
+
+int pingu_ping_send(struct ev_loop *loop, struct pingu_host *host)
+{
+	int packetlen = sizeof(struct iphdr) + sizeof(struct icmphdr);
+	struct pingu_ping *ping;
+	int seq, r;
+
+	seq = pingu_ping_get_seq();
+	r = icmp_send_ping(host->iface->fd, &host->burst.saddr,
+			       sizeof(host->burst.saddr), seq, packetlen);
+	if (r < 0)
+		return -1;
+
+	ping = pingu_ping_add(loop, host, seq);
+	return ping == NULL ? -1 : 0;
+}
+
+void pingu_ping_read_reply(struct ev_loop *loop, struct pingu_iface *iface)
+{
+	struct sockaddr from;
+	unsigned char buf[1500];
+	struct iphdr *ip = (struct iphdr *) buf;
+	struct pingu_ping *ping;
+
+	int len = icmp_read_reply(iface->fd, &from, sizeof(from), buf,
+				  sizeof(buf));
+	if (len <= 0)
+		return;
+	
+	ping = pingu_ping_find((struct icmphdr *) &buf[ip->ihl * 4], &from,
+			       &iface->ping_list);
+	if (ping == NULL)
+		return;
+
+	pingu_ping_handle_reply(loop, ping);
+}
+