146 lines
3.7 KiB
C
146 lines
3.7 KiB
C
/* ************************************************************************** */
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/* */
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/* ::: :::::::: */
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/* main.c :+: :+: :+: */
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/* +:+ +:+ +:+ */
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/* By: jhalford <jack@crans.org> +#+ +:+ +#+ */
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/* +#+#+#+#+#+ +#+ */
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/* Created: 2017/04/22 14:10:24 by jhalford #+# #+# */
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/* Updated: 2017/04/23 18:18:41 by jhalford ### ########.fr */
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/* */
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/* ************************************************************************** */
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#include "ft_ping.h"
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int g_pid=-1;
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unsigned short checksum(void *b, int len)
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{
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unsigned short *buf = b;
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unsigned int sum=0;
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unsigned short result;
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for (sum = 0; len > 1; len -= 2)
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sum += *buf++;
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if (len == 1)
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sum += *(unsigned char*)buf;
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sum = (sum >> 16) + (sum & 0xFFFF);
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sum += (sum >> 16);
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result = ~sum;
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return (result);
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}
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void display(void *buf, int bytes, struct sockaddr_in *addr)
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{
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int i;
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struct ip *ip = buf;
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struct icmp *icmp = buf + ip->ip_hl*4;
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printf("%d bytes from %s: ttl=%i\n",
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ip->ip_len, inet_ntoa(addr->sin_addr), ip->ip_ttl);
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printf("IPv%d: hrd-size=%d, pkt-size=%d, id=%d, frag-off=%d, protocol=%c\n, ttl=%i",
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ip->ip_v, ip->ip_hl, ip->ip_len, ip->ip_id, ip->ip_off, ip->ip_p, ip->ip_ttl);
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if (icmp->icmp_hun.ih_idseq.icd_id == g_pid)
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{
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printf("ICMP: type[%d/%d] checksum[%d] id[%d] seq[%d]\n",
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icmp->icmp_type, icmp->icmp_code, ntohs(icmp->icmp_cksum),
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icmp->icmp_hun.ih_idseq.icd_id, icmp->icmp_hun.ih_idseq.icd_seq);
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(void)bytes;
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}
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for (i=0; i < bytes; i++)
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{
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if ( !(i & 15) ) printf("\n%i: ", i);
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printf("%c ", ((char*)buf)[i]);
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}
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printf("\n");
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}
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void listener(struct sockaddr_in *addr)
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{
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int sd;
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struct sockaddr_in r_addr;
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int bytes;
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socklen_t len;
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unsigned char buf[1024];
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if ((sd = socket(PF_INET, SOCK_DGRAM, IPPROTO_ICMP)) < 0)
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{
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perror("socket");
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exit(0);
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}
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for (;;)
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{
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bzero(buf, sizeof(buf));
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len = sizeof(r_addr);
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bytes = recvfrom(sd, buf, sizeof(buf), 0, (struct sockaddr*)&r_addr, &len);
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if (bytes > 0)
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display(buf, bytes, addr);
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else
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perror("recvfrom");
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}
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}
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void ping(struct sockaddr_in *addr)
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{
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const int val;
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int i;
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int sd;
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int cnt;
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socklen_t len;
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struct s_packet pkt;
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struct sockaddr_in r_addr;
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if ((sd = socket(PF_INET, SOCK_DGRAM, IPPROTO_ICMP)) < 0)
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{
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perror("socket");
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return ;
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}
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if (setsockopt(sd, 0, IP_TTL, &val, sizeof(val)) != 0)
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perror("set TTL option");
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if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0)
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perror("Request non blocking IO");
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cnt = 1;
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while (1)
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{
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len = sizeof(r_addr);
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recvfrom(sd, &pkt, sizeof(pkt), 0, (struct sockaddr*)&r_addr, &len);
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bzero(&pkt, sizeof(pkt));
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pkt.icmp.icmp_type = ICMP_ECHO;
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pkt.icmp.icmp_hun.ih_idseq.icd_id = g_pid;
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for (i=0; i < (int)sizeof(pkt.msg); i++)
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pkt.msg[i] = i+'0';
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pkt.msg[i] = 0;
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pkt.icmp.icmp_hun.ih_idseq.icd_seq = cnt++;
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pkt.icmp.icmp_cksum = checksum(&pkt, sizeof(pkt));
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if (sendto(sd, &pkt, sizeof(pkt), 0, (struct sockaddr*)addr, sizeof(*addr)) <= 0)
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perror("sendto");
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sleep(1);
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}
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}
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int main(int ac, char **av)
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{
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struct sockaddr_in *addr;
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struct addrinfo *result;
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if (ac != 2)
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{
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printf("usage: %s <addr>\n", av[0]);
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exit(1);
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}
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if (getaddrinfo(av[1], NULL, NULL, &result) != 0)
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{
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perror("getaddrinfo");
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exit(1);
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}
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addr = (struct sockaddr_in*)result->ai_addr;
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if (fork() == 0)
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{
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listener(addr);
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exit(0);
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}
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else
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ping(addr);
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wait(0);
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return (0);
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}
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