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ping.c
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ping.c
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/*
* Copyright (c) 1989 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Mike Muuss.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1989 The Regents of the University of California.\n\
All rights reserved.\n";
#endif /* not lint */
/*
* P I N G . C
*
* Using the InterNet Control Message Protocol (ICMP) "ECHO" facility,
* measure round-trip-delays and packet loss across network paths.
*
* Author -
* Mike Muuss
* U. S. Army Ballistic Research Laboratory
* December, 1983
*
* Status -
* Public Domain. Distribution Unlimited.
* Bugs -
* More statistics could always be gathered.
* If kernel does not support non-raw ICMP sockets,
* this program has to run SUID to ROOT or with
* net_cap_raw enabled.
*/
#include "ping_common.h"
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#ifndef WITHOUT_IFADDRS
#include <ifaddrs.h>
#endif
#ifndef ICMP_FILTER
#define ICMP_FILTER 1
struct icmp_filter {
__u32 data;
};
#endif
#define MAXIPLEN 60
#define MAXICMPLEN 76
#define NROUTES 9 /* number of record route slots */
#define TOS_MAX 255 /* 8-bit TOS field */
#define MAX_HOSTNAMELEN NI_MAXHOST
static int ts_type;
static int nroute = 0;
static __u32 route[10];
struct sockaddr_in whereto; /* who to ping */
int optlen = 0;
int settos = 0; /* Set TOS, Precendence or other QOS options */
int icmp_sock; /* socket file descriptor */
extern int using_ping_socket;
u_char outpack[0x10000];
int maxpacket = sizeof(outpack);
static int broadcast_pings = 0;
static char *pr_addr(__u32);
static void pr_options(unsigned char * cp, int hlen);
static void pr_iph(struct iphdr *ip);
static void usage(void) __attribute__((noreturn));
static u_short in_cksum(const u_short *addr, int len, u_short salt);
static void pr_icmph(__u8 type, __u8 code, __u32 info, struct icmphdr *icp);
static int parsetos(char *str);
static struct {
struct cmsghdr cm;
struct in_pktinfo ipi;
} cmsg = { {sizeof(struct cmsghdr) + sizeof(struct in_pktinfo), SOL_IP, IP_PKTINFO},
{0, }};
int cmsg_len;
struct sockaddr_in source;
char *device;
int pmtudisc = -1;
int
main(int argc, char **argv)
{
struct hostent *hp;
int ch, hold, packlen;
int socket_errno;
u_char *packet;
char *target;
#ifdef USE_IDN
char *hnamebuf = NULL;
#else
char hnamebuf[MAX_HOSTNAMELEN];
#endif
char rspace[3 + 4 * NROUTES + 1]; /* record route space */
limit_capabilities();
#ifdef USE_IDN
setlocale(LC_ALL, "");
#endif
enable_capability_raw();
icmp_sock = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
disable_capability_raw();
if (icmp_sock < 0) {
icmp_sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP);
using_ping_socket = 1;
working_recverr = 1;
}
socket_errno = errno;
source.sin_family = AF_INET;
preload = 1;
while ((ch = getopt(argc, argv, COMMON_OPTSTR "bRT:")) != EOF) {
switch(ch) {
case 'b':
broadcast_pings = 1;
break;
case 'Q':
settos = parsetos(optarg);
if (settos &&
(setsockopt(icmp_sock, IPPROTO_IP, IP_TOS,
(char *)&settos, sizeof(int)) < 0)) {
perror("ping: error setting QOS sockopts");
exit(2);
}
break;
case 'R':
if (options & F_TIMESTAMP) {
fprintf(stderr, "Only one of -T or -R may be used\n");
exit(2);
}
options |= F_RROUTE;
break;
case 'T':
if (options & F_RROUTE) {
fprintf(stderr, "Only one of -T or -R may be used\n");
exit(2);
}
options |= F_TIMESTAMP;
if (strcmp(optarg, "tsonly") == 0)
ts_type = IPOPT_TS_TSONLY;
else if (strcmp(optarg, "tsandaddr") == 0)
ts_type = IPOPT_TS_TSANDADDR;
else if (strcmp(optarg, "tsprespec") == 0)
ts_type = IPOPT_TS_PRESPEC;
else {
fprintf(stderr, "Invalid timestamp type\n");
exit(2);
}
break;
case 'I':
{
#if 0
char dummy;
int i1, i2, i3, i4;
if (sscanf(optarg, "%u.%u.%u.%u%c",
&i1, &i2, &i3, &i4, &dummy) == 4) {
__u8 *ptr;
ptr = (__u8*)&source.sin_addr;
ptr[0] = i1;
ptr[1] = i2;
ptr[2] = i3;
ptr[3] = i4;
options |= F_STRICTSOURCE;
} else {
device = optarg;
}
#else
if (inet_pton(AF_INET, optarg, &source.sin_addr) > 0)
options |= F_STRICTSOURCE;
else
device = optarg;
#endif
break;
}
case 'M':
if (strcmp(optarg, "do") == 0)
pmtudisc = IP_PMTUDISC_DO;
else if (strcmp(optarg, "dont") == 0)
pmtudisc = IP_PMTUDISC_DONT;
else if (strcmp(optarg, "want") == 0)
pmtudisc = IP_PMTUDISC_WANT;
else {
fprintf(stderr, "ping: wrong value for -M: do, dont, want are valid ones.\n");
exit(2);
}
break;
case 'V':
printf("ping utility, iputils-%s\n", SNAPSHOT);
exit(0);
COMMON_OPTIONS
common_options(ch);
break;
default:
usage();
}
}
argc -= optind;
argv += optind;
if (argc == 0)
usage();
if (argc > 1) {
if (options & F_RROUTE)
usage();
else if (options & F_TIMESTAMP) {
if (ts_type != IPOPT_TS_PRESPEC)
usage();
if (argc > 5)
usage();
} else {
if (argc > 10)
usage();
options |= F_SOURCEROUTE;
}
}
while (argc > 0) {
target = *argv;
memset((char *)&whereto, 0, sizeof(whereto));
whereto.sin_family = AF_INET;
if (inet_aton(target, &whereto.sin_addr) == 1) {
hostname = target;
if (argc == 1)
options |= F_NUMERIC;
} else {
char *idn;
#ifdef USE_IDN
int rc;
if (hnamebuf) {
free(hnamebuf);
hnamebuf = NULL;
}
rc = idna_to_ascii_lz(target, &idn, 0);
if (rc != IDNA_SUCCESS) {
fprintf(stderr, "ping: IDN encoding failed: %s\n", idna_strerror(rc));
exit(2);
}
#else
idn = target;
#endif
hp = gethostbyname(idn);
if (!hp) {
fprintf(stderr, "ping: unknown host %s\n", target);
exit(2);
}
#ifdef USE_IDN
free(idn);
#endif
memcpy(&whereto.sin_addr, hp->h_addr, 4);
#ifdef USE_IDN
if (idna_to_unicode_lzlz(hp->h_name, &hnamebuf, 0) != IDNA_SUCCESS) {
hnamebuf = strdup(hp->h_name);
if (!hnamebuf) {
perror("ping: strdup");
exit(-1);
}
}
#else
strncpy(hnamebuf, hp->h_name, sizeof(hnamebuf) - 1);
hnamebuf[sizeof(hnamebuf) - 1] = 0;
#endif
hostname = hnamebuf;
}
if (argc > 1)
route[nroute++] = whereto.sin_addr.s_addr;
argc--;
argv++;
}
if (source.sin_addr.s_addr == 0) {
socklen_t alen;
struct sockaddr_in dst = whereto;
int probe_fd = socket(AF_INET, SOCK_DGRAM, 0);
if (probe_fd < 0) {
perror("socket");
exit(2);
}
if (device) {
struct ifreq ifr;
int rc;
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, device, IFNAMSIZ-1);
enable_capability_raw();
rc = setsockopt(probe_fd, SOL_SOCKET, SO_BINDTODEVICE, device, strlen(device)+1);
disable_capability_raw();
if (rc == -1) {
if (IN_MULTICAST(ntohl(dst.sin_addr.s_addr))) {
struct ip_mreqn imr;
if (ioctl(probe_fd, SIOCGIFINDEX, &ifr) < 0) {
fprintf(stderr, "ping: unknown iface %s\n", device);
exit(2);
}
memset(&imr, 0, sizeof(imr));
imr.imr_ifindex = ifr.ifr_ifindex;
if (setsockopt(probe_fd, SOL_IP, IP_MULTICAST_IF, &imr, sizeof(imr)) == -1) {
perror("ping: IP_MULTICAST_IF");
exit(2);
}
} else {
perror("ping: SO_BINDTODEVICE");
exit(2);
}
}
}
if (settos &&
setsockopt(probe_fd, IPPROTO_IP, IP_TOS, (char *)&settos, sizeof(int)) < 0)
perror("Warning: error setting QOS sockopts");
dst.sin_port = htons(1025);
if (nroute)
dst.sin_addr.s_addr = route[0];
if (connect(probe_fd, (struct sockaddr*)&dst, sizeof(dst)) == -1) {
if (errno == EACCES) {
if (broadcast_pings == 0) {
fprintf(stderr, "Do you want to ping broadcast? Then -b\n");
exit(2);
}
fprintf(stderr, "WARNING: pinging broadcast address\n");
if (setsockopt(probe_fd, SOL_SOCKET, SO_BROADCAST,
&broadcast_pings, sizeof(broadcast_pings)) < 0) {
perror ("can't set broadcasting");
exit(2);
}
if (connect(probe_fd, (struct sockaddr*)&dst, sizeof(dst)) == -1) {
perror("connect");
exit(2);
}
} else {
perror("connect");
exit(2);
}
}
alen = sizeof(source);
if (getsockname(probe_fd, (struct sockaddr*)&source, &alen) == -1) {
perror("getsockname");
exit(2);
}
source.sin_port = 0;
#ifndef WITHOUT_IFADDRS
if (device) {
struct ifaddrs *ifa0, *ifa;
int ret;
ret = getifaddrs(&ifa0);
if (ret) {
fprintf(stderr, "gatifaddrs() failed.\n");
exit(2);
}
for (ifa = ifa0; ifa; ifa = ifa->ifa_next) {
if (!ifa->ifa_addr || ifa->ifa_addr->sa_family != AF_INET)
continue;
if (!strncmp(ifa->ifa_name, device, sizeof(device) - 1) &&
!memcmp(&((struct sockaddr_in *)ifa->ifa_addr)->sin_addr,
&source.sin_addr, sizeof(source.sin_addr)))
break;
}
freeifaddrs(ifa0);
if (!ifa)
fprintf(stderr, "ping: Warning: source address might be selected on device other than %s.\n", device);
}
#endif
close(probe_fd);
} while (0);
if (whereto.sin_addr.s_addr == 0)
whereto.sin_addr.s_addr = source.sin_addr.s_addr;
if (icmp_sock < 0) {
errno = socket_errno;
perror("ping: icmp open socket");
exit(2);
}
if (device) {
struct ifreq ifr;
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, device, IFNAMSIZ-1);
if (ioctl(icmp_sock, SIOCGIFINDEX, &ifr) < 0) {
fprintf(stderr, "ping: unknown iface %s\n", device);
exit(2);
}
cmsg.ipi.ipi_ifindex = ifr.ifr_ifindex;
cmsg_len = sizeof(cmsg);
}
if (broadcast_pings || IN_MULTICAST(ntohl(whereto.sin_addr.s_addr))) {
if (uid) {
if (interval < 1000) {
fprintf(stderr, "ping: broadcast ping with too short interval.\n");
exit(2);
}
if (pmtudisc >= 0 && pmtudisc != IP_PMTUDISC_DO) {
fprintf(stderr, "ping: broadcast ping does not fragment.\n");
exit(2);
}
}
if (pmtudisc < 0)
pmtudisc = IP_PMTUDISC_DO;
}
if (pmtudisc >= 0) {
if (setsockopt(icmp_sock, SOL_IP, IP_MTU_DISCOVER, &pmtudisc, sizeof(pmtudisc)) == -1) {
perror("ping: IP_MTU_DISCOVER");
exit(2);
}
}
if ((options&F_STRICTSOURCE) &&
bind(icmp_sock, (struct sockaddr*)&source, sizeof(source)) == -1) {
perror("bind");
exit(2);
}
if (!using_ping_socket) {
struct icmp_filter filt;
filt.data = ~((1<<ICMP_SOURCE_QUENCH)|
(1<<ICMP_DEST_UNREACH)|
(1<<ICMP_TIME_EXCEEDED)|
(1<<ICMP_PARAMETERPROB)|
(1<<ICMP_REDIRECT)|
(1<<ICMP_ECHOREPLY));
if (setsockopt(icmp_sock, SOL_RAW, ICMP_FILTER, (char*)&filt, sizeof(filt)) == -1)
perror("WARNING: setsockopt(ICMP_FILTER)");
}
hold = 1;
if (setsockopt(icmp_sock, SOL_IP, IP_RECVERR, (char *)&hold, sizeof(hold)))
fprintf(stderr, "WARNING: your kernel is veeery old. No problems.\n");
if (using_ping_socket) {
if (setsockopt(icmp_sock, SOL_IP, IP_RECVTTL,
(char *)&hold, sizeof(hold)))
perror("WARNING: setsockopt(IP_RECVTTL)");
if (setsockopt(icmp_sock, SOL_IP, IP_RETOPTS,
(char *)&hold, sizeof(hold)))
perror("WARNING: setsockopt(IP_RETOPTS)");
}
/* record route option */
if (options & F_RROUTE) {
memset(rspace, 0, sizeof(rspace));
rspace[0] = IPOPT_NOP;
rspace[1+IPOPT_OPTVAL] = IPOPT_RR;
rspace[1+IPOPT_OLEN] = sizeof(rspace)-1;
rspace[1+IPOPT_OFFSET] = IPOPT_MINOFF;
optlen = 40;
if (setsockopt(icmp_sock, IPPROTO_IP, IP_OPTIONS, rspace, sizeof(rspace)) < 0) {
perror("ping: record route");
exit(2);
}
}
if (options & F_TIMESTAMP) {
memset(rspace, 0, sizeof(rspace));
rspace[0] = IPOPT_TIMESTAMP;
rspace[1] = (ts_type==IPOPT_TS_TSONLY ? 40 : 36);
rspace[2] = 5;
rspace[3] = ts_type;
if (ts_type == IPOPT_TS_PRESPEC) {
int i;
rspace[1] = 4+nroute*8;
for (i=0; i<nroute; i++)
*(__u32*)&rspace[4+i*8] = route[i];
}
if (setsockopt(icmp_sock, IPPROTO_IP, IP_OPTIONS, rspace, rspace[1]) < 0) {
rspace[3] = 2;
if (setsockopt(icmp_sock, IPPROTO_IP, IP_OPTIONS, rspace, rspace[1]) < 0) {
perror("ping: ts option");
exit(2);
}
}
optlen = 40;
}
if (options & F_SOURCEROUTE) {
int i;
memset(rspace, 0, sizeof(rspace));
rspace[0] = IPOPT_NOOP;
rspace[1+IPOPT_OPTVAL] = (options & F_SO_DONTROUTE) ? IPOPT_SSRR
: IPOPT_LSRR;
rspace[1+IPOPT_OLEN] = 3 + nroute*4;
rspace[1+IPOPT_OFFSET] = IPOPT_MINOFF;
for (i=0; i<nroute; i++)
*(__u32*)&rspace[4+i*4] = route[i];
if (setsockopt(icmp_sock, IPPROTO_IP, IP_OPTIONS, rspace, 4 + nroute*4) < 0) {
perror("ping: record route");
exit(2);
}
optlen = 40;
}
/* Estimate memory eaten by single packet. It is rough estimate.
* Actually, for small datalen's it depends on kernel side a lot. */
hold = datalen + 8;
hold += ((hold+511)/512)*(optlen + 20 + 16 + 64 + 160);
sock_setbufs(icmp_sock, hold);
if (broadcast_pings) {
if (setsockopt(icmp_sock, SOL_SOCKET, SO_BROADCAST,
&broadcast_pings, sizeof(broadcast_pings)) < 0) {
perror ("ping: can't set broadcasting");
exit(2);
}
}
if (options & F_NOLOOP) {
int loop = 0;
if (setsockopt(icmp_sock, IPPROTO_IP, IP_MULTICAST_LOOP,
&loop, 1) == -1) {
perror ("ping: can't disable multicast loopback");
exit(2);
}
}
if (options & F_TTL) {
int ittl = ttl;
if (setsockopt(icmp_sock, IPPROTO_IP, IP_MULTICAST_TTL,
&ttl, 1) == -1) {
perror ("ping: can't set multicast time-to-live");
exit(2);
}
if (setsockopt(icmp_sock, IPPROTO_IP, IP_TTL,
&ittl, sizeof(ittl)) == -1) {
perror ("ping: can't set unicast time-to-live");
exit(2);
}
}
if (datalen > 0xFFFF - 8 - optlen - 20) {
if (uid || datalen > sizeof(outpack)-8) {
fprintf(stderr, "Error: packet size %d is too large. Maximum is %d\n", datalen, 0xFFFF-8-20-optlen);
exit(2);
}
/* Allow small oversize to root yet. It will cause EMSGSIZE. */
fprintf(stderr, "WARNING: packet size %d is too large. Maximum is %d\n", datalen, 0xFFFF-8-20-optlen);
}
if (datalen >= sizeof(struct timeval)) /* can we time transfer */
timing = 1;
packlen = datalen + MAXIPLEN + MAXICMPLEN;
if (!(packet = (u_char *)malloc((u_int)packlen))) {
fprintf(stderr, "ping: out of memory.\n");
exit(2);
}
printf("PING %s (%s) ", hostname, inet_ntoa(whereto.sin_addr));
if (device || (options&F_STRICTSOURCE))
printf("from %s %s: ", inet_ntoa(source.sin_addr), device ?: "");
printf("%d(%d) bytes of data.\n", datalen, datalen+8+optlen+20);
setup(icmp_sock);
main_loop(icmp_sock, packet, packlen);
}
int receive_error_msg()
{
int res;
char cbuf[512];
struct iovec iov;
struct msghdr msg;
struct cmsghdr *cmsg;
struct sock_extended_err *e;
struct icmphdr icmph;
struct sockaddr_in target;
int net_errors = 0;
int local_errors = 0;
int saved_errno = errno;
iov.iov_base = &icmph;
iov.iov_len = sizeof(icmph);
msg.msg_name = (void*)⌖
msg.msg_namelen = sizeof(target);
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_flags = 0;
msg.msg_control = cbuf;
msg.msg_controllen = sizeof(cbuf);
res = recvmsg(icmp_sock, &msg, MSG_ERRQUEUE|MSG_DONTWAIT);
if (res < 0)
goto out;
e = NULL;
for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
if (cmsg->cmsg_level == SOL_IP) {
if (cmsg->cmsg_type == IP_RECVERR)
e = (struct sock_extended_err *)CMSG_DATA(cmsg);
}
}
if (e == NULL)
abort();
if (e->ee_origin == SO_EE_ORIGIN_LOCAL) {
local_errors++;
if (options & F_QUIET)
goto out;
if (options & F_FLOOD)
write_stdout("E", 1);
else if (e->ee_errno != EMSGSIZE)
fprintf(stderr, "ping: local error: %s\n", strerror(e->ee_errno));
else
fprintf(stderr, "ping: local error: Message too long, mtu=%u\n", e->ee_info);
nerrors++;
} else if (e->ee_origin == SO_EE_ORIGIN_ICMP) {
struct sockaddr_in *sin = (struct sockaddr_in*)(e+1);
if (res < sizeof(icmph) ||
target.sin_addr.s_addr != whereto.sin_addr.s_addr ||
icmph.type != ICMP_ECHO ||
!is_ours(icmph.un.echo.id)) {
/* Not our error, not an error at all. Clear. */
saved_errno = 0;
goto out;
}
acknowledge(ntohs(icmph.un.echo.sequence));
if (!using_ping_socket && !working_recverr) {
struct icmp_filter filt;
working_recverr = 1;
/* OK, it works. Add stronger filter. */
filt.data = ~((1<<ICMP_SOURCE_QUENCH)|
(1<<ICMP_REDIRECT)|
(1<<ICMP_ECHOREPLY));
if (setsockopt(icmp_sock, SOL_RAW, ICMP_FILTER, (char*)&filt, sizeof(filt)) == -1)
perror("\rWARNING: setsockopt(ICMP_FILTER)");
}
net_errors++;
nerrors++;
if (options & F_QUIET)
goto out;
if (options & F_FLOOD) {
write_stdout("\bE", 2);
} else {
print_timestamp();
printf("From %s icmp_seq=%u ", pr_addr(sin->sin_addr.s_addr), ntohs(icmph.un.echo.sequence));
pr_icmph(e->ee_type, e->ee_code, e->ee_info, NULL);
fflush(stdout);
}
}
out:
errno = saved_errno;
return net_errors ? : -local_errors;
}
/*
* pinger --
* Compose and transmit an ICMP ECHO REQUEST packet. The IP packet
* will be added on by the kernel. The ID field is our UNIX process ID,
* and the sequence number is an ascending integer. The first 8 bytes
* of the data portion are used to hold a UNIX "timeval" struct in VAX
* byte-order, to compute the round-trip time.
*/
int send_probe()
{
struct icmphdr *icp;
int cc;
int i;
icp = (struct icmphdr *)outpack;
icp->type = ICMP_ECHO;
icp->code = 0;
icp->checksum = 0;
icp->un.echo.sequence = htons(ntransmitted+1);
icp->un.echo.id = ident; /* ID */
rcvd_clear(ntransmitted+1);
if (timing) {
if (options&F_LATENCY) {
struct timeval tmp_tv;
gettimeofday(&tmp_tv, NULL);
memcpy(icp+1, &tmp_tv, sizeof(tmp_tv));
} else {
memset(icp+1, 0, sizeof(struct timeval));
}
}
cc = datalen + 8; /* skips ICMP portion */
/* compute ICMP checksum here */
icp->checksum = in_cksum((u_short *)icp, cc, 0);
if (timing && !(options&F_LATENCY)) {
struct timeval tmp_tv;
gettimeofday(&tmp_tv, NULL);
memcpy(icp+1, &tmp_tv, sizeof(tmp_tv));
icp->checksum = in_cksum((u_short *)&tmp_tv, sizeof(tmp_tv), ~icp->checksum);
}
do {
static struct iovec iov = {outpack, 0};
static struct msghdr m = { &whereto, sizeof(whereto),
&iov, 1, &cmsg, 0, 0 };
m.msg_controllen = cmsg_len;
iov.iov_len = cc;
i = sendmsg(icmp_sock, &m, confirm);
confirm = 0;
} while (0);
return (cc == i ? 0 : i);
}
/*
* parse_reply --
* Print out the packet, if it came from us. This logic is necessary
* because ALL readers of the ICMP socket get a copy of ALL ICMP packets
* which arrive ('tis only fair). This permits multiple copies of this
* program to be run without having intermingled output (or statistics!).
*/
void pr_echo_reply(__u8 *_icp, int len)
{
struct icmphdr *icp = (struct icmphdr *)_icp;
printf(" icmp_seq=%u", ntohs(icp->un.echo.sequence));
}
int
parse_reply(struct msghdr *msg, int cc, void *addr, struct timeval *tv)
{
struct sockaddr_in *from = addr;
__u8 *buf = msg->msg_iov->iov_base;
struct icmphdr *icp;
struct iphdr *ip;
int hlen;
int csfailed;
struct cmsghdr *cmsg;
int ttl;
__u8 *opts;
int optlen;
/* Check the IP header */
ip = (struct iphdr *)buf;
if (!using_ping_socket) {
hlen = ip->ihl*4;
if (cc < hlen + 8 || ip->ihl < 5) {
if (options & F_VERBOSE)
fprintf(stderr, "ping: packet too short (%d bytes) from %s\n", cc,
pr_addr(from->sin_addr.s_addr));
return 1;
}
ttl = ip->ttl;
opts = buf + sizeof(struct iphdr);
optlen = hlen - sizeof(struct iphdr);
} else {
hlen = 0;
ttl = 0;
opts = buf;
optlen = 0;
for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
if (cmsg->cmsg_level != SOL_IP)
continue;
if (cmsg->cmsg_type == IP_TTL) {
if (cmsg->cmsg_len < sizeof(int))
continue;
ttl = *(int *) CMSG_DATA(cmsg);
} else if (cmsg->cmsg_type == IP_RETOPTS) {
opts = (__u8 *) CMSG_DATA(cmsg);
optlen = cmsg->cmsg_len;
}
}
}
/* Now the ICMP part */
cc -= hlen;
icp = (struct icmphdr *)(buf + hlen);
csfailed = in_cksum((u_short *)icp, cc, 0);
if (icp->type == ICMP_ECHOREPLY) {
if (!is_ours(icp->un.echo.id))
return 1; /* 'Twas not our ECHO */
if (gather_statistics((__u8*)icp, sizeof(*icp), cc,
ntohs(icp->un.echo.sequence),
ttl, 0, tv, pr_addr(from->sin_addr.s_addr),
pr_echo_reply))
return 0;
} else {
/* We fall here when a redirect or source quench arrived.
* Also this branch processes icmp errors, when IP_RECVERR
* is broken. */
switch (icp->type) {
case ICMP_ECHO:
/* MUST NOT */
return 1;
case ICMP_SOURCE_QUENCH:
case ICMP_REDIRECT:
case ICMP_DEST_UNREACH:
case ICMP_TIME_EXCEEDED:
case ICMP_PARAMETERPROB:
{
struct iphdr * iph = (struct iphdr *)(&icp[1]);
struct icmphdr *icp1 = (struct icmphdr*)((unsigned char *)iph + iph->ihl*4);
int error_pkt;
if (cc < 8+sizeof(struct iphdr)+8 ||
cc < 8+iph->ihl*4+8)
return 1;
if (icp1->type != ICMP_ECHO ||
iph->daddr != whereto.sin_addr.s_addr ||
!is_ours(icp1->un.echo.id))
return 1;
error_pkt = (icp->type != ICMP_REDIRECT &&
icp->type != ICMP_SOURCE_QUENCH);
if (error_pkt) {
acknowledge(ntohs(icp1->un.echo.sequence));
if (working_recverr) {
return 0;
} else {
static int once;
/* Sigh, IP_RECVERR for raw socket
* was broken until 2.4.9. So, we ignore
* the first error and warn on the second.
*/
if (once++ == 1)
fprintf(stderr, "\rWARNING: kernel is not very fresh, upgrade is recommended.\n");
if (once == 1)
return 0;
}
}
nerrors+=error_pkt;
if (options&F_QUIET)
return !error_pkt;
if (options & F_FLOOD) {
if (error_pkt)
write_stdout("\bE", 2);
return !error_pkt;
}
print_timestamp();
printf("From %s: icmp_seq=%u ",
pr_addr(from->sin_addr.s_addr),
ntohs(icp1->un.echo.sequence));
if (csfailed)
printf("(BAD CHECKSUM)");
pr_icmph(icp->type, icp->code, ntohl(icp->un.gateway), icp);
return !error_pkt;
}
default:
/* MUST NOT */
break;
}
if ((options & F_FLOOD) && !(options & (F_VERBOSE|F_QUIET))) {
if (!csfailed)
write_stdout("!E", 2);
else
write_stdout("!EC", 3);
return 0;
}
if (!(options & F_VERBOSE) || uid)
return 0;
if (options & F_PTIMEOFDAY) {
struct timeval recv_time;
gettimeofday(&recv_time, NULL);
printf("%lu.%06lu ", (unsigned long)recv_time.tv_sec, (unsigned long)recv_time.tv_usec);
}
printf("From %s: ", pr_addr(from->sin_addr.s_addr));
if (csfailed) {
printf("(BAD CHECKSUM)\n");
return 0;
}
pr_icmph(icp->type, icp->code, ntohl(icp->un.gateway), icp);
return 0;
}
if (options & F_AUDIBLE) {
putchar('\a');
if (options & F_FLOOD)
fflush(stdout);
}
if (!(options & F_FLOOD)) {
pr_options(opts, optlen + sizeof(struct iphdr));
putchar('\n');
fflush(stdout);
}
return 0;
}
#if BYTE_ORDER == LITTLE_ENDIAN
# define ODDBYTE(v) (v)
#elif BYTE_ORDER == BIG_ENDIAN
# define ODDBYTE(v) ((u_short)(v) << 8)
#else
# define ODDBYTE(v) htons((u_short)(v) << 8)
#endif
u_short
in_cksum(const u_short *addr, register int len, u_short csum)
{
register int nleft = len;
const u_short *w = addr;
register u_short answer;
register int sum = csum;
/*
* Our algorithm is simple, using a 32 bit accumulator (sum),
* we add sequential 16 bit words to it, and at the end, fold
* back all the carry bits from the top 16 bits into the lower
* 16 bits.
*/
while (nleft > 1) {
sum += *w++;
nleft -= 2;
}
/* mop up an odd byte, if necessary */
if (nleft == 1)
sum += ODDBYTE(*(u_char *)w); /* le16toh() may be unavailable on old systems */
/*
* add back carry outs from top 16 bits to low 16 bits
*/
sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
sum += (sum >> 16); /* add carry */
answer = ~sum; /* truncate to 16 bits */
return (answer);
}
/*
* pr_icmph --
* Print a descriptive string about an ICMP header.
*/
void pr_icmph(__u8 type, __u8 code, __u32 info, struct icmphdr *icp)
{
switch(type) {
case ICMP_ECHOREPLY:
printf("Echo Reply\n");
/* XXX ID + Seq + Data */
break;
case ICMP_DEST_UNREACH:
switch(code) {
case ICMP_NET_UNREACH:
printf("Destination Net Unreachable\n");
break;
case ICMP_HOST_UNREACH:
printf("Destination Host Unreachable\n");
break;
case ICMP_PROT_UNREACH:
printf("Destination Protocol Unreachable\n");
break;
case ICMP_PORT_UNREACH:
printf("Destination Port Unreachable\n");
break;
case ICMP_FRAG_NEEDED: