Annotation of embedaddon/hping2/sendtcp.c, revision 1.1.1.1
1.1 misho 1: /*
2: * $smu-mark$
3: * $name: sendtcp.c$
4: * $author: Salvatore Sanfilippo <antirez@invece.org>$
5: * $copyright: Copyright (C) 1999 by Salvatore Sanfilippo$
6: * $license: This software is under GPL version 2 of license$
7: * $date: Fri Nov 5 11:55:49 MET 1999$
8: * $rev: 8$
9: */
10:
11: #include <stdio.h>
12: #include <string.h>
13: #include <stdlib.h>
14: #include <time.h>
15: #include <sys/time.h>
16: #include <unistd.h>
17: #include <signal.h>
18:
19: #include "hping2.h"
20: #include "globals.h"
21:
22: void send_tcp(void)
23: {
24: int packet_size;
25: int tcp_opt_size = 0;
26: char *packet, *data;
27: struct mytcphdr *tcp;
28: struct pseudohdr *pseudoheader;
29: unsigned char *tstamp;
30:
31: if (opt_tcp_timestamp)
32: tcp_opt_size = 12;
33:
34: packet_size = TCPHDR_SIZE + tcp_opt_size + data_size;
35: packet = malloc(PSEUDOHDR_SIZE + packet_size);
36: if (packet == NULL) {
37: perror("[send_tcphdr] malloc()");
38: return;
39: }
40: pseudoheader = (struct pseudohdr*) packet;
41: tcp = (struct mytcphdr*) (packet+PSEUDOHDR_SIZE);
42: tstamp = (unsigned char*) (packet+PSEUDOHDR_SIZE+TCPHDR_SIZE);
43: data = (char*) (packet+PSEUDOHDR_SIZE+TCPHDR_SIZE+tcp_opt_size);
44:
45: memset(packet, 0, PSEUDOHDR_SIZE+packet_size);
46:
47: /* tcp pseudo header */
48: memcpy(&pseudoheader->saddr, &local.sin_addr.s_addr, 4);
49: memcpy(&pseudoheader->daddr, &remote.sin_addr.s_addr, 4);
50: pseudoheader->protocol = 6; /* tcp */
51: pseudoheader->lenght = htons(TCPHDR_SIZE+tcp_opt_size+data_size);
52:
53: /* tcp header */
54: tcp->th_dport = htons(dst_port);
55: tcp->th_sport = htons(src_port);
56:
57: /* sequence number and ack are random if not set */
58: tcp->th_seq = (set_seqnum) ? htonl(tcp_seqnum) : htonl(rand());
59: tcp->th_ack = (set_ack) ? htonl(tcp_ack) : htonl(rand());
60:
61: tcp->th_off = src_thoff + (tcp_opt_size >> 2);
62: tcp->th_win = htons(src_winsize);
63: tcp->th_flags = tcp_th_flags;
64:
65: /* tcp timestamp option */
66: if (opt_tcp_timestamp) {
67: __u32 randts = rand() ^ (rand() << 16);
68: tstamp[0] = tstamp[1] = 1; /* NOOP */
69: tstamp[2] = 8;
70: tstamp[3] = 10; /* 10 bytes, kind+len+T1+T2 */
71: memcpy(tstamp+4, &randts, 4); /* random */
72: memset(tstamp+8, 0, 4); /* zero */
73: }
74:
75: /* data */
76: data_handler(data, data_size);
77:
78: /* compute checksum */
79: #ifdef STUPID_SOLARIS_CHECKSUM_BUG
80: tcp->th_sum = packet_size;
81: #else
82: tcp->th_sum = cksum((u_short*) packet, PSEUDOHDR_SIZE +
83: packet_size);
84: #endif
85:
86: /* adds this pkt in delaytable */
87: delaytable_add(sequence, src_port, time(NULL), get_usec(), S_SENT);
88:
89: /* send packet */
90: send_ip_handler(packet+PSEUDOHDR_SIZE, packet_size);
91: free(packet);
92:
93: sequence++; /* next sequence number */
94: if (!opt_keepstill)
95: src_port = (sequence + initsport) % 65536;
96:
97: if (opt_force_incdport)
98: dst_port++;
99: }
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