#ifdef __linux#include <stdlib.h>#include <string.h>#include <sys/socket.h>#include <arpa/inet.h>#include <netdb.h>#include "linux.h"#else#include <u.h>#include <libc.h>#endif #include "dat.h"#include "fns.h" flapconn* newflapconn(char *addr){	flapconn *ret = calloc(1, sizeof(flapconn));#ifdef __linux	struct sockaddr_in inet_addr;	struct hostent *host_addr;	char *ptr2;	int port;	char *ptr = strchr(addr, '!');	if (ptr == NULL)		exits("addr0");	ptr++;	if (*ptr == '\0')		exits("addr1"); 	ptr2 = strchr(ptr, '!');	if (ptr2 == NULL)		exits("addr2");	*ptr2 = '\0';	ptr2++;	if (*ptr2 == '\0')		exits("addr3");	port = atoi(ptr2); 	if ((host_addr = gethostbyname(ptr)) == NULL)		exits("gethostbyname"); 	if ((ret->fd = socket(AF_INET, SOCK_STREAM, 0)) == -1)		exits("socket"); 	inet_addr.sin_family = AF_INET;	inet_addr.sin_port = htons(port);	inet_addr.sin_addr = *((struct in_addr*) host_addr->h_addr);	memset(&(inet_addr.sin_zero), '\0', 8); 	if ((connect(ret->fd, (struct sockaddr *)&inet_addr,			    sizeof(struct sockaddr))) == -1)		exits("connect");#else	ret->fd = dial(addr, nil, nil, nil);#endif	if (ret->fd < 0) {		exits("dial");	}	srand(time(nil));	ret->seq = rand() % 0x8000; 	return ret;} int sendflap(flapconn *fc, flap *f){	uchar byte[1] = { 0x2a }; 	if (write(fc->fd, byte, 1) < 1){		exits("sendflap: write 0x2A");	}	if (write(fc->fd, &f->channel, 1) < 1){		exits("sendflap: write f->channel");	} 	byte[0] = fc->seq >> 8;	write(fc->fd, byte, 1);	byte[0] = fc->seq & 0xFF;	write (fc->fd, byte, 1); 	fc->seq++;	if (fc->seq >= 0x8000)		fc->seq = 0; 	byte[0] = f->length >> 8;	write(fc->fd, byte, 1);	byte[0] = f->length & 0xFF;	write(fc->fd, byte, 1); 	if (f->length) {		write(fc->fd, f->data, f->length);	} 	return 0;} flap* newflap(uchar channel){	flap *ret = calloc(1, sizeof(flap)); 	ret->channel = channel; 	return ret;} void freeflap(flap *f){	if (f->data)		free(f->data);	free (f);} int recvflap(flapconn *fc, flap *f){	int i, r;	char buf[10];	f->offset = 0; 	r = read(fc->fd, buf, 1);	if (r != 1)		exits("recvflap: first char\n");	if (buf[0] != 0x2A)		exits("recvflap: first char != *\n"); 	r = read(fc->fd, &buf[1], 1);	if (r != 1)		exits("recvflap: channel\n");	f->channel = (uchar)buf[1]; 	r = read(fc->fd, &buf[2], 2);	if (r != 2)		exits("recvflap: sequence number\n");// TODO sequence number 	r = read(fc->fd, &buf[4], 2);	if (r != 2)		exits("recvflap: error reading length\n");	f->length = (uchar)buf[4] << 8 | (uchar)buf[5]; 	f->data = calloc(1, f->length); //	print("0x%x\n", f->length);		for (i = 0; i < f->length; i += r) {		r = read(fc->fd, &f->data[i], f->length - i);		if (r < 1)			exits("recvflap: error reading data\n");	} 	return 0;} ushort get2(flap *f){	if ((f->length - 2) < f->offset)		exits("short get2"); 	return (f->data[f->offset++] << 8 | f->data[f->offset++]);} uint get4(flap *f) {	uint ret = (uint)get2(f) << 16;	ret |= get2(f);	return ret;} unsigned long long get8(flap *f) {	unsigned long long ret = (unsigned long long)get4(f) << 32;	ret |= get4(f);	return ret;} void put1(flap *f, uchar c) {	while (f->offset >= f->length) {		f->length++;		f->data = realloc(f->data, f->length);	}	f->data[f->offset++] = c;} void put2(flap *f, ushort u){	put1(f, u >> 8);	put1(f, u & 0xFF);} void put4(flap *f, uint i) {	put2(f, i >> 16);	put2(f, i & 0xFFFF);} void put8(flap *f, unsigned long long i) {	put4(f, i >> 32);	put4(f, i & 0xFFFFFFFF);}