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- /*
- * ZMap Copyright 2013 Regents of the University of Michigan
- *
- * Licensed under the Apache License, Version 2.0 (the "License"); you may not
- * use this file except in compliance with the License. You may obtain a copy
- * of the License at http://www.apache.org/licenses/LICENSE-2.0
- */
- #include <stdlib.h>
- #include <stdio.h>
- #include <string.h>
- #include <assert.h>
- #include "../../lib/includes.h"
- #include "../../lib/xalloc.h"
- #include "packet.h"
- #include "../state.h"
- #ifndef NDEBUG
- void print_macaddr(struct ifreq* i)
- {
- printf("Device %s -> Ethernet %02x:%02x:%02x:%02x:%02x:%02x\n",
- i->ifr_name,
- (int) ((unsigned char *) &i->ifr_addr.sa_data)[0],
- (int) ((unsigned char *) &i->ifr_addr.sa_data)[1],
- (int) ((unsigned char *) &i->ifr_addr.sa_data)[2],
- (int) ((unsigned char *) &i->ifr_addr.sa_data)[3],
- (int) ((unsigned char *) &i->ifr_addr.sa_data)[4],
- (int) ((unsigned char *) &i->ifr_addr.sa_data)[5]);
- }
- #endif /* NDEBUG */
- #define IP_ADDR_LEN_STR 20
- void fprintf_ip_header(FILE *fp, struct ip *iph)
- {
- struct in_addr *s = (struct in_addr *) &(iph->ip_src);
- struct in_addr *d = (struct in_addr *) &(iph->ip_dst);
- char srcip[IP_ADDR_LEN_STR+1];
- char dstip[IP_ADDR_LEN_STR+1];
- // inet_ntoa is a const char * so we if just call it in
- // fprintf, you'll get back wrong results since we're
- // calling it twice.
- strncpy(srcip, inet_ntoa(*s), IP_ADDR_LEN_STR - 1);
- strncpy(dstip, inet_ntoa(*d), IP_ADDR_LEN_STR - 1);
- srcip[IP_ADDR_LEN_STR] = '\0';
- dstip[IP_ADDR_LEN_STR] = '\0';
- fprintf(fp, "ip { saddr: %s | daddr: %s | checksum: %#04X }\n",
- srcip,
- dstip,
- ntohs(iph->ip_sum));
- }
- void fprintf_eth_header(FILE *fp, struct ether_header *ethh)
- {
- fprintf(fp, "eth { shost: %02x:%02x:%02x:%02x:%02x:%02x | "
- "dhost: %02x:%02x:%02x:%02x:%02x:%02x }\n",
- (int) ((unsigned char *) ethh->ether_shost)[0],
- (int) ((unsigned char *) ethh->ether_shost)[1],
- (int) ((unsigned char *) ethh->ether_shost)[2],
- (int) ((unsigned char *) ethh->ether_shost)[3],
- (int) ((unsigned char *) ethh->ether_shost)[4],
- (int) ((unsigned char *) ethh->ether_shost)[5],
- (int) ((unsigned char *) ethh->ether_dhost)[0],
- (int) ((unsigned char *) ethh->ether_dhost)[1],
- (int) ((unsigned char *) ethh->ether_dhost)[2],
- (int) ((unsigned char *) ethh->ether_dhost)[3],
- (int) ((unsigned char *) ethh->ether_dhost)[4],
- (int) ((unsigned char *) ethh->ether_dhost)[5]);
- }
- void make_eth_header(struct ether_header *ethh, macaddr_t *src, macaddr_t *dst)
- {
- memcpy(ethh->ether_shost, src, ETHER_ADDR_LEN);
- memcpy(ethh->ether_dhost, dst, ETHER_ADDR_LEN);
- ethh->ether_type = htons(ETHERTYPE_IP);
- }
- void make_ip_header(struct ip *iph, uint8_t protocol, uint16_t len)
- {
- iph->ip_hl = 5; // Internet Header Length
- iph->ip_v = 4; // IPv4
- iph->ip_tos = 0; // Type of Service
- iph->ip_len = len;
- iph->ip_id = htons(54321); // identification number
- iph->ip_off = 0; //fragmentation flag
- iph->ip_ttl = MAXTTL; // time to live (TTL)
- iph->ip_p = protocol; // upper layer protocol => TCP
- // we set the checksum = 0 for now because that's
- // what it needs to be when we run the IP checksum
- iph->ip_sum = 0;
- }
- void make_icmp_header(struct icmp *buf)
- {
- buf->icmp_type = ICMP_ECHO;
- buf->icmp_code = 0;
- buf->icmp_seq = 0;
- }
- void make_tcp_header(struct tcphdr *tcp_header, port_h_t dest_port)
- {
- tcp_header->th_seq = random();
- tcp_header->th_ack = 0;
- tcp_header->th_x2 = 0;
- tcp_header->th_off = 5; // data offset
- tcp_header->th_flags = 0;
- tcp_header->th_flags |= TH_SYN;
- tcp_header->th_win = htons(65535); // largest possible window
- tcp_header->th_sum = 0;
- tcp_header->th_urp = 0;
- tcp_header->th_dport = htons(dest_port);
- }
- void make_udp_header(struct udphdr *udp_header, port_h_t dest_port,
- uint16_t len)
- {
- udp_header->uh_dport = htons(dest_port);
- udp_header->uh_ulen = htons(len);
- // checksum ignored in IPv4 if 0
- udp_header->uh_sum = 0;
- }
- // Note: caller must free return value
- char *make_ip_str(uint32_t ip)
- {
- struct in_addr t;
- t.s_addr = ip;
- const char *temp = inet_ntoa(t);
- char *retv = xmalloc(strlen(temp)+1);
- strcpy(retv, temp);
- return retv;
- }
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