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| #include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <netinet/udp.h>
#define BUFSIZE 1500
struct rec{
u_short rec_seq;
u_short rec_ttl;
struct timeval rec_tv;
};
char recvbuf[BUFSIZE];
char sendbuf[BUFSIZE];
int datalen;
char *host;
u_short sport, dport;
int nsent;
pid_t pid;
int probe, nprobes;
int sendfd, recvfd;
int ttl, max_ttl;
int verbose;
int gotalarm;
const char *icmpcode_v4(int);
const char *icmpcode_v6(int);
int recv_v4(int ,struct timeval *);
int recv_v6(int ,struct timeval *);
void sig_alrm(int );
void traceloop(void);
void tv_sub(struct timeval *, struct timeval *);
struct proto {
const char *(*icmpcode)(int);
int (*recv)(int , struct timeval *);
struct sockaddr *sasend;
struct sockaddr *sarecv;
struct sockaddr *salast;
struct sockaddr *sabind;
socklen_t salen;
int icmpproto;
int ttllevel;
int ttloptname;
}*pr;
#ifdef IPV6
#include <netinet/ip6.h>
#include <netinet/icmp6.h>
#endif
struct proto proto_v4 = { icmpcode_v4, recv_v4, NULL, NULL, NULL, NULL, 0,
IPPROTO_ICMP, IPPROTO_IP, IP_TTL};
#ifdef IPV6
struct proto proto_v6 ={icmpcode_v6, recv_v6, NULL, NULL, NULL, 0,
IPPROTO_ICMPV6, IPPROTO_IPV6, IPV6_UNICAST_HOPS};
#endif
int datalen = sizeof(struct rec);
int max_ttl = 30;
int nprobes = 3;
u_short dport = 32768 + 666;
int main(int argc, char **argv)
{
int c;
struct addrinfo *a;
char *h;
opterr = 0;
while( ( c = getopt(argc, argv, "m:v")) != -1)
{
switch(c)
{
case 'm':
if( ( max_ttl = atoi(optarg)) <= 1)
printf("invalid -m value");
break;
case 'v':
verbose++;
break;
case '?':
printf("unrecognized option:%c", c);
}
}
if( optind != argc -1)
printf("usage : traceroute [ -m <maxttl> -v] <hostname>");
host = argv[optind];
pid = getpid();
signal(SIGALRM, sig_alrm);
ai = host_serv(host, NULL, 0, 0);
h = sock_ntop_host(ai->ai_addr, ai->ai_addrlen);
printf("traceroute to %s (%s): %d hops max, %d data bytes \n", ai->ai_canonname? ai->ai_canonname:h, h,max_ttl, datalen);
if ( ai->ai_family == AF_INET )
{
pr = &proto_v4;
#ifdef IPV6
}
else if (ai->ai_family == AF_INET6)
{
pr = &proto_v6;
if(IN6_IS_ADDR_V4MAPPED(&(((struct sockaddr_in6 *) ai->ai_addr)->sin6_addr)))
printf("cannot traceroute IPV4-mapped IPV6 address");
#endif
}
else
printf("unknown address family %d", ai->ai_family);
pr->sasend = ai->si_addr;
pr->sarecv = calloc(1, ai->ai_addrlen);
pr->salast = calloc(1, ai->ai_addrlen);
pr->sabind = calloc(1, ai->ai_addrlen);
pr->salen =ai->ai_addrlen;
traceloop();
exit();
}
void traceloop(void)
{
int seq, code, done;
double rtt;
struct rec *rec;
struct timeval tvrecv;
recvfd = socket(pr->sasend->sa_family, SOCK_RAW, pr->icmpproto); /*创建两个套接字*/
setuid(getuid());
#ifdef IPV6
if ( pr->sasend->sa_family == AF_INET6 && verbose == 0) /*设置ICMPv6接收过滤器*/
{
struct icmp6_filter myfilt;
ICMP6_FILTER_SETBLOCKALL(&myfilt);
ICMP6_FILTER_SETPASS(ICMP6_TIME_EXCEEDED, &myfilt);
ICMP6_FILTER_SETPASS(ICMP6_DST_UNREACH, &myfilt);
setsockopt(recvfd, IPPROTO_IPV6, ICMP6_FILTER,
&myfilt, sizeof(myfilt));
}
#endif
sendfd = socket(pr->sasend->sa_family,SOCK_DGRAM, 0); /*给UDP套接字捆绑源端口*/
pr->sabind->sa_family = pr->sasend->sa_family;
sport = (getpid() &0xffff) | 0x8000;
sock_set_port(pr->sabind, pr->salen, htons(sport));
bind(sendfd, pr->sabind, pr->salen);
sig_alrm(SIGALRM); /*建立SIGALRM的信号处理函数*/
seq = 0;
done = 0;
for (ttl = 1; ttl < max_ttl && done ==0; ttl ++) /*主循环,设置TTL或跳限并发送3个探测分组*/
{
setsockopt(sendfd, pr->ttllevel, pr->ttloptname, &ttl, sizeof(int));
bzero( pr->salast , pr->salen);
printf("%2d", ttl );
fflush(stdout);
for( probe = 0; probe < nprobes; probe ++)
{
rec = (struct rec*) sendbuf;
rec->rec_seq = ++seq;
rec->rec_ttl = ttl;
gettimeofday(&rec->rec_tv, NULL);
sock_set_port(pr->sasend, pr->salen, htons(dport+ seq)); /*设置目的端口并发送UDP数据报*/
sendto(sendfd, sendbuf,datalen, 0, pr->sasend, pr->salen);
if( ( code = (*pr->recv)(seq, &tvrecv)) == -3) /*读取ICMP消息*/
printf(" * ");
else /*显示应答*/
{
char str[NI_MAXHOST];
if( sock_cmp_addr( pr->sarecv, pr->salast, pr->salen ) != 0)
{
if( getnameinfo(pr->sarecv, pr->salen, str, sizeof(str),NULL, 0, 0) == 0)
{
printf(" %s (%s)", str, sock_ntop_host(pr->sarecv, pr->salen));
}
else
printf("%s", sock_ntop_host(pr->sarecv, pr->salen));
memcpy( pr->salast, pr->sarecv, pr->salen);
}
tv_sub(&tvrecv, &rec->rec_tv);
rtt = tvrecv.tv_sec*1000.0 + tvrecv.tv_usec/1000.0;
printf(" %.3f ms", rtt);
if( code == -1)
done++;
else if(code >= 0)
printf(" (ICMP %s)", (*pr->icmpcode)(code));
}
fflush(stdout);
}
printf("\n");
}
}
int recv_v4(int seq, struct timeval *tv)
{
int hlen1, hlen2, icmplen ,ret;
socklen_t len;
ssize_t n;
struct ip *ip, *hip;
struct icmp *icmp;
struct udphdr *udp;
gotalarm = 0;
alarm(3); /*设置报警时钟并读入每个ICMP消息*/
for( ; ;)
{
if(gotalarm)
return (-3);
len = pr->salen;
n = recvfrom(recvfd, recvbuf, sizeof(recvbuf), 0, pr->sarecv, &len);
if( n < 0)
{
if ( errno == EINTR)
continue;
else
printf("recvfrom error");
}
ip = (struct ip *) recvbuf; /*获取ICMP首部指针*/
hlen1 = ip->ip_hl << 2;
icmp = (struct icmp *) (recvbuf + hlen1);
if( (icmplen = n - hlen1 ) < 8)
continue;
if( icmp->icmp_type == ICMP_TIMXCEED &&
icmp->icmp_code == ICMP_TIMXCEED_INTRANS) /*处理ICMP传输中超时错误*/
{
if( icmplen < 8 + sizeof(struct ip))
continue;
hip = (struct ip *)( recvbuf + hlen1 + 8);
hlen2 = hip->ip_hl << 2;
if( icmplen < 8 + hlen2 + 4)
continue;
udp = (struct udphdr *) (recvbuf + hlen1 + 8 + hlen2);
if( hip->ip_p == IPPROTO_UDP && udp->uh_sport == htons(sport)
&& udp->uh_dport == htons(dport + seq))
{
ret = -2;
break;
}
}
else if ( icmp->icmp_type == ICMP_UNREACH)/*处理ICMP传输中不可达错误*/
{
if ( icmplen < 8 + sizeof( struct ip) )
continue;
hip = (struct ip *)(recvbuf + hlen1 + 8);
hlen2 = hip->ip_hl << 2;
if( icmplen < 8 + hlen2 + 4)
continue;
udp = (struct udphdr *) (recvbuf + hlen1 + 8 + hlen2);
if( hip->ip_p == IPPROTO_UDP && udp->uh_sport == htons(sport)
&& udp->uh_dport == htons(dport + seq))
{
if( icmp->icmp_code == ICMP_UNREACH_PORT)
ret = -1;
else
ret = icmp->icmp_code;
break;
}
}
if( verbose)
{
printf(" (from %s: type = %d, code = %d)\n",sock_ntop_host(pr->sarecv, pr->salen),
icmp->icmp_type, icmp->icmp_code);
}
}
alarm(0);
gettimeofday(tv, NULL);
return (ret);
}
void sig_alrm(int signo)
{
gotalarm = 1;
return;
}
int recv_v6(int seq, struct timeval *tv)
{
#ifdef IPV6
int hlen2, icmp6len ,ret;
socklen_t len;
ssize_t n;
struct ip6_hdr *hip6;
struct icmp6_hdr *icmp6;
struct udphdr *udp;
gotalarm = 0;
alarm(3);
for( ; ;)
{
if(gotalarm)
return (-3);
len = pr->salen;
n = recvfrom(recvfd, recvbuf, sizeof(recvbuf), 0, pr->sarecv, &len);
if( n < 0)
{
if ( errno == EINTR)
continue;
else
printf("recvfrom error");
}
icmp6 = (struct icmp6_hdr *) recvbuf ;
if( (icmp6len = n ) < 8)
continue;
if( icmp6->icmp6_type == ICMP6_TIME_EXCEEDED &&
icmp6->icmp6_code == CMP6_TIME_EXCEEDED_INTRANS)
{
if( icmp6len < 8 + sizeof(struct ip6_hdr) + 4)
continue;
hip6 = (struct ip6_hdr *)( recvbuf+ 8);
hlen2 = sizeof( struct ip6_hdr);
udp = (struct udphdr *) (recvbuf + 8 + hlen2);
if( hip6->ip6_nxt == IPPROTO_UDP && udp->uh_sport == htons(sport)
&& udp->uh_dport == htons(dport + seq))
{
ret = -2;
break;
}
}
else if ( icmp6->icmp6_type == ICMP6_DST_UNREACH)
{
if ( icmp6len < 8 + sizeof( struct ip6_hdr) + 4) )
continue;
hip6 = (struct ip6_hdr *)( recvbuf+ 8);
hlen2 = sizeof( struct ip6_hdr);
udp = (struct udphdr *) (recvbuf + 8 + hlen2);
if( hip6->ip6_nxt == IPPROTO_UDP && udp->uh_sport == htons(sport)
&& udp->uh_dport == htons(dport + seq))
{
if( icmp6->icmp6_code == ICMP6_DST_UNREACH_NOPORT)
ret = -1;
else
ret = icmp6->icmp6_code;
break;
}
}
if( verbose)
{
printf(" (from %s: type = %d, code = %d)\n",sock_ntop_host(pr->sarecv, pr->salen),
icmp6->icmp6_type, icmp6->icmp6_code);
}
}
alarm(0);
gettimeofday(tv, NULL);
return (ret);
#endif
}
|