[Nagiosplug-devel] Fwd: Patch proposal for check_icmp
Holger Weiss
holger at CIS.FU-Berlin.DE
Thu Dec 20 20:48:12 CET 2007
* Patrick Cervicek <patrick.postfix at cervicek.de> [2007-12-20 20:27]:
> Ton Voon schrieb:
> > I got this email from Harald re: check_icmp specifying a source
> > address. I don't know too much about check_icmp, so can anyone else
> > look over this?
Looks fine to me (apart from the fact that it won't work with IPv6, but
check_icmp currently doesn't support IPv6 anyway; we should fix this
sometime). I cleaned things up a bit and added the possibility to
specify interface names (which doesn't require root-privileges). If
nobody objects, I'll commit the attached version of the patch.
> > +#include <netinet/in.h>
>
> 1) in.h is already included 5 lines higher. Is this #include necessary?
No.
> > + if (bind(icmp_sock, (struct sockaddr *) &src, sizeof(struct sockaddr_un)) == -1) {
>
> 2) Wouldn't it better to check before, if 'icmp_sock' or 'sockets' is >0 ?
That's not necessary. If icmp_sock wasn't created the bind(2) call will
fail and the plugin will spit out an error message such as "check_icmp:
Cannot bind to IP address 127.0.0.1: Bad file descriptor".
> 3) Is 'sizeof(struct sockaddr_UN)' good?
Nope.
Thanks to Harald for the patch and thanks to Patrick for looking into
it!
Holger
-------------- next part --------------
Index: check_icmp.c
===================================================================
--- check_icmp.c (revision 1880)
+++ check_icmp.c (working copy)
@@ -54,6 +54,7 @@
#include "netutils.h"
#include "utils.h"
+#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/types.h>
#include <stdio.h>
@@ -66,6 +67,7 @@
#include <ctype.h>
#include <netdb.h>
#include <sys/socket.h>
+#include <net/if.h>
#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip.h>
@@ -178,11 +180,13 @@
void print_usage (void);
static u_int get_timevar(const char *);
static u_int get_timevaldiff(struct timeval *, struct timeval *);
+static in_addr_t get_ip_address(const char *);
static int wait_for_reply(int, u_int);
static int recvfrom_wto(int, char *, unsigned int, struct sockaddr *, u_int *);
static int send_icmp_ping(int, struct rta_host *);
static int get_threshold(char *str, threshold *th);
static void run_checks(void);
+static void set_source_ip(char *);
static int add_target(char *);
static int add_target_ip(char *, struct in_addr *);
static int handle_random_icmp(struct icmp *, struct sockaddr_in *);
@@ -446,7 +450,7 @@
/* parse the arguments */
for(i = 1; i < argc; i++) {
- while((arg = getopt(argc, argv, "vhVw:c:n:p:t:H:i:b:I:l:m:")) != EOF) {
+ while((arg = getopt(argc, argv, "vhVw:c:n:p:t:H:S:i:b:I:l:m:")) != EOF) {
switch(arg) {
case 'v':
debug++;
@@ -489,6 +493,9 @@
crit_down = (unsigned char)strtoul(ptr + 1, NULL, 0);
}
break;
+ case 'S': /* specify source ip for ping */
+ set_source_ip(optarg);
+ break;
case 'V': /* version */
/*print_revision (progname, revision);*/ /* FIXME: Why? */
exit (STATE_OK);
@@ -1109,6 +1116,40 @@
return 0;
}
+
+static void
+set_source_ip(char *arg)
+{
+ struct sockaddr_in src;
+
+ memset(&src, 0, sizeof(src));
+ src.sin_family = AF_INET;
+ if((src.sin_addr.s_addr = inet_addr(arg)) == INADDR_NONE)
+ src.sin_addr.s_addr = get_ip_address(arg);
+ if (bind(icmp_sock, (struct sockaddr *)&src, sizeof(src)) == -1)
+ crash("Cannot bind to IP address %s", arg);
+}
+
+/* TODO: Move this to netutils.c and also change check_dhcp to use that. */
+static in_addr_t
+get_ip_address(const char *ifname)
+{
+#if defined(SIOCGIFADDR)
+ struct ifreq ifr;
+ struct in_addr ip;
+
+ strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name) - 1);
+ ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = '\0';
+ if (ioctl(icmp_sock, SIOCGIFADDR, &ifr) == -1)
+ crash("Cannot determine IP address of interface %s", ifname);
+ ip = ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr;
+ return ip.s_addr;
+#else
+ errno = 0;
+ crash("Cannot get interface IP address on this platform.");
+#endif
+}
+
/*
* u = micro
* m = milli
@@ -1225,6 +1266,8 @@
printf (" %s\n", "-H");
printf (" %s\n", _("specify a target"));
+ printf (" %s\n", "-S");
+ printf (" %s\n", _("specify a source IP address or device name"));
printf (" %s\n", "-w");
printf (" %s", _("warning threshold (currently "));
printf ("%0.3fms,%u%%)\n", (float)warn.rta / 1000 , warn.pl / 1000);
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