Files
glorytun/src/main.c
2015-12-04 11:13:46 +01:00

1068 lines
26 KiB
C

#include <inttypes.h>
#include <limits.h>
#include <stdio.h>
#include <signal.h>
#include <poll.h>
#include <sys/time.h>
#include <sys/fcntl.h>
#include <sys/socket.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <sodium.h>
#include "common-static.h"
#include "ip-static.h"
#include "option.h"
#include "tun.h"
#ifndef O_CLOEXEC
#define O_CLOEXEC 0
#endif
#define GT_BUFFER_SIZE (4*1024*1024)
#define GT_TIMEOUT (5000)
#define GT_MTU_MAX (1500)
#define GT_TUNR_SIZE (0x7FFF-16)
#define GT_TUNW_SIZE (0x7FFF)
struct fdbuf {
int fd;
buffer_t read;
buffer_t write;
};
struct blk {
size_t size;
uint8_t data[GT_MTU_MAX] _align_(16);
};
struct crypto_ctx {
struct {
crypto_aead_aes256gcm_state state;
uint8_t nonce[crypto_aead_aes256gcm_NPUBBYTES];
} write, read;
uint8_t skey[crypto_generichash_KEYBYTES];
};
volatile sig_atomic_t gt_close = 0;
volatile sig_atomic_t gt_info = 0;
static int64_t dt_ms (struct timeval *ta, struct timeval *tb)
{
const int64_t s = ta->tv_sec-tb->tv_sec;
const int64_t n = ta->tv_usec-tb->tv_usec;
return s*1000LL+n/1000LL;
}
static void fd_set_nonblock (int fd)
{
int ret;
do {
ret = fcntl(fd, F_GETFL, 0);
} while (ret==-1 && errno==EINTR);
int flags = (ret==-1)?0:ret;
do {
ret = fcntl(fd, F_SETFL, flags|O_NONBLOCK);
} while (ret==-1 && errno==EINTR);
if (ret==-1)
perror("fcntl O_NONBLOCK");
}
enum sk_opt {
sk_nodelay,
sk_reuseaddr,
sk_keepalive,
sk_keepcnt,
sk_keepidle,
sk_keepintvl,
sk_congestion,
sk_defer_accept,
sk_quickack,
};
static void sk_set (int fd, enum sk_opt opt, const void *val, socklen_t len)
{
if (!val || len<=0)
return;
struct {
const char *name;
const int present;
const int level;
const int option;
} opts[] = {
[sk_nodelay] = { "TCP_NODELAY", 1, IPPROTO_TCP, TCP_NODELAY, },
[sk_reuseaddr] = { "SO_REUSEADDR", 1, SOL_SOCKET, SO_REUSEADDR, },
[sk_keepalive] = { "SO_KEEPALIVE", 1, SOL_SOCKET, SO_KEEPALIVE, },
[sk_keepcnt] = { "TCP_KEEPCNT",
#ifdef TCP_KEEPCNT
1, IPPROTO_TCP, TCP_KEEPCNT,
#endif
},
[sk_keepidle] = { "TCP_KEEPIDLE",
#ifdef TCP_KEEPIDLE
1, IPPROTO_TCP, TCP_KEEPIDLE,
#endif
},
[sk_keepintvl] = { "TCP_KEEPINTVL",
#ifdef TCP_KEEPINTVL
1, IPPROTO_TCP, TCP_KEEPINTVL,
#endif
},
[sk_congestion] = { "TCP_CONGESTION",
#ifdef TCP_CONGESTION
1, IPPROTO_TCP, TCP_CONGESTION,
#endif
},
[sk_defer_accept] = { "TCP_DEFER_ACCEPT",
#ifdef TCP_DEFER_ACCEPT
1, IPPROTO_TCP, TCP_DEFER_ACCEPT,
#endif
},
[sk_quickack] = { "TCP_QUICKACK",
#ifdef TCP_QUICKACK
1, IPPROTO_TCP, TCP_QUICKACK,
#endif
},
};
if (!opts[opt].present) {
gt_na(opts[opt].name);
return;
}
if (setsockopt(fd, opts[opt].level, opts[opt].option, val, len)==-1)
gt_log("couldn't set socket option `%s'\n", opts[opt].name);
}
static void sk_set_int (int fd, enum sk_opt opt, int val)
{
return sk_set(fd, opt, &val, sizeof(val));
}
static int sk_listen (int fd, struct addrinfo *ai)
{
sk_set_int(fd, sk_reuseaddr, 1);
int ret = bind(fd, ai->ai_addr, ai->ai_addrlen);
if (ret==-1) {
perror("bind");
return -1;
}
ret = listen(fd, 8);
if (ret==-1) {
perror("listen");
return -1;
}
sk_set_int(fd, sk_defer_accept, GT_TIMEOUT/1000);
return 0;
}
static int sk_connect (int fd, struct addrinfo *ai)
{
int ret = connect(fd, ai->ai_addr, ai->ai_addrlen);
if (ret==-1 && errno==EINTR)
return 0;
return ret;
}
static int sk_create (struct addrinfo *res, int(*func)(int, struct addrinfo *))
{
for (struct addrinfo *ai=res; ai; ai=ai->ai_next) {
int fd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
if (fd==-1)
continue;
if (func(fd, ai)!=-1)
return fd;
close(fd);
}
return -1;
}
static int sk_accept (int fd)
{
struct sockaddr_storage addr;
socklen_t addr_size = sizeof(addr);
int ret = accept(fd, (struct sockaddr *)&addr, &addr_size);
if (ret==-1 && errno!=EINTR)
perror("accept");
return ret;
}
static char *sk_get_name (int fd)
{
struct sockaddr_storage addr;
socklen_t addr_size = sizeof(addr);
if (getpeername(fd, (struct sockaddr *)&addr, &addr_size)==-1) {
perror("getpeername");
return NULL;
}
char host[64] = {0};
char port[32] = {0};
int ret = getnameinfo((struct sockaddr *)&addr, addr_size,
host, sizeof(host),
port, sizeof(port),
NI_NUMERICHOST|NI_NUMERICSERV);
switch (ret) {
case 0:
break;
case EAI_MEMORY:
errno = ENOMEM;
case EAI_SYSTEM:
perror("getnameinfo");
return NULL;
}
const char *const strs[] = {
host, ".", port
};
return str_cat(strs, COUNT(strs));
}
#ifdef TCP_INFO
static socklen_t sk_get_info (int fd, struct tcp_info *ti)
{
socklen_t len = sizeof(struct tcp_info);
if (getsockopt(fd, SOL_TCP, TCP_INFO, ti, &len)==-1) {
perror("getsockopt TCP_INFO");
return 0;
}
return len;
}
static void print_tcp_info (const char *name, struct tcp_info *ti)
{
gt_log("%s: tcpinfo"
" rto:%" PRIu32 " ato:%" PRIu32 " snd_mss:%" PRIu32
" rcv_mss:%" PRIu32 " unacked:%" PRIu32 " sacked:%" PRIu32
" lost:%" PRIu32 " retrans:%" PRIu32 " fackets:%" PRIu32
" pmtu:%" PRIu32 " rcv_ssthresh:%" PRIu32 " rtt:%" PRIu32
" rttvar:%" PRIu32 " snd_ssthresh:%" PRIu32 " snd_cwnd:%" PRIu32
" advmss:%" PRIu32 " reordering:%" PRIu32 "\n",
name,
ti->tcpi_rto, ti->tcpi_ato, ti->tcpi_snd_mss,
ti->tcpi_rcv_mss, ti->tcpi_unacked, ti->tcpi_sacked,
ti->tcpi_lost, ti->tcpi_retrans, ti->tcpi_fackets,
ti->tcpi_pmtu, ti->tcpi_rcv_ssthresh, ti->tcpi_rtt,
ti->tcpi_rttvar, ti->tcpi_snd_ssthresh, ti->tcpi_snd_cwnd,
ti->tcpi_advmss, ti->tcpi_reordering);
}
#endif
static struct addrinfo *ai_create (const char *host, const char *port, int listener)
{
if (!port || !port[0]) {
gt_log("port is not valid\n");
return NULL;
}
struct addrinfo hints = {
.ai_family = AF_UNSPEC,
.ai_socktype = SOCK_STREAM,
.ai_protocol = IPPROTO_TCP,
};
if (listener)
hints.ai_flags = AI_PASSIVE;
struct addrinfo *ai = NULL;
int ret = getaddrinfo(host, port, &hints, &ai);
switch (ret) {
case 0:
return ai;
case EAI_MEMORY:
errno = ENOMEM;
case EAI_SYSTEM:
perror("getaddrinfo");
break;
case EAI_FAIL:
case EAI_AGAIN:
gt_log("the name server returned a failure\n");
break;
default:
gt_log("%s.%s is not valid\n", host?:"", port);
}
return NULL;
}
static void gt_sa_handler (int sig)
{
switch (sig) {
case SIGINT:
case SIGQUIT:
case SIGTERM:
gt_close = 1;
break;
case SIGUSR1:
gt_info = 1;
break;
}
}
static void gt_set_signal (void)
{
struct sigaction sa = {
.sa_flags = 0,
};
sigemptyset(&sa.sa_mask);
sa.sa_handler = gt_sa_handler;
sigaction(SIGINT, &sa, NULL);
sigaction(SIGQUIT, &sa, NULL);
sigaction(SIGTERM, &sa, NULL);
sigaction(SIGUSR1, &sa, NULL);
sa.sa_handler = SIG_IGN;
sigaction(SIGHUP, &sa, NULL);
sigaction(SIGPIPE, &sa, NULL);
sigaction(SIGUSR2, &sa, NULL);
}
static ssize_t fd_read (int fd, void *data, size_t size)
{
if (!size)
return -1;
ssize_t ret = read(fd, data, size);
if (ret==-1) {
if (errno==EAGAIN || errno==EINTR)
return -1;
if (errno)
perror("read");
return 0;
}
return ret;
}
static ssize_t fd_write (int fd, const void *data, size_t size)
{
if (!size)
return -1;
ssize_t ret = write(fd, data, size);
if (ret==-1) {
if (errno==EAGAIN || errno==EINTR)
return -1;
if (errno)
perror("write");
return 0;
}
return ret;
}
static ssize_t fd_read_all (int fd, void *data, size_t size)
{
size_t done = 0;
struct pollfd pollfd = {
.fd = fd,
.events = POLLIN,
};
while (done<size) {
ssize_t ret = fd_read(fd, (uint8_t *)data+done, size-done);
if (!ret)
break;
if (ret<0) {
if (!poll(&pollfd, 1, GT_TIMEOUT))
break;
continue;
}
done += ret;
}
return done;
}
static ssize_t fd_write_all (int fd, const void *data, size_t size)
{
size_t done = 0;
struct pollfd pollfd = {
.fd = fd,
.events = POLLOUT,
};
while (done<size) {
ssize_t ret = fd_write(fd, (const uint8_t *)data+done, size-done);
if (!ret)
break;
if (ret<0) {
if (!poll(&pollfd, 1, GT_TIMEOUT))
break;
continue;
}
done += ret;
}
return done;
}
static int gt_encrypt (struct crypto_ctx *ctx, buffer_t *dst, buffer_t *src)
{
const size_t rs = buffer_read_size(src);
const size_t ws = buffer_write_size(dst);
if (!rs || !ws)
return 0;
const size_t size = rs+crypto_aead_aes256gcm_ABYTES;
if (size+2>ws)
return 0;
dst->write[0] = 0xFF&(size>>8);
dst->write[1] = 0xFF&(size);
crypto_aead_aes256gcm_encrypt_afternm(
dst->write+2, NULL,
src->read, rs,
dst->write, 2,
NULL, ctx->write.nonce,
(const crypto_aead_aes256gcm_state *)&ctx->write.state);
sodium_increment(ctx->write.nonce, crypto_aead_aes256gcm_NPUBBYTES);
src->read += rs;
dst->write += size+2;
return 0;
}
static int gt_decrypt (struct crypto_ctx *ctx, buffer_t *dst, buffer_t *src)
{
const size_t rs = buffer_read_size(src);
const size_t ws = buffer_write_size(dst);
if (!rs || !ws)
return 0;
if (rs<=2+crypto_aead_aes256gcm_ABYTES)
return 0;
const size_t size = (src->read[0]<<8)|src->read[1];
if (size-crypto_aead_aes256gcm_ABYTES>ws)
return 0;
if (size+2>rs)
return 0;
if (crypto_aead_aes256gcm_decrypt_afternm(
dst->write, NULL,
NULL,
src->read+2, size,
src->read, 2,
ctx->read.nonce,
(const crypto_aead_aes256gcm_state *)&ctx->read.state))
return -1;
sodium_increment(ctx->read.nonce, crypto_aead_aes256gcm_NPUBBYTES);
src->read += size+2;
dst->write += size-crypto_aead_aes256gcm_ABYTES;
return 0;
}
static void dump_ip_header (uint8_t *data, size_t size)
{
if (size<20)
return;
const char tbl[] = "0123456789ABCDEF";
char hex[41];
for (size_t i=0; i<20; i++) {
hex[(i<<1)+0] = tbl[0xF&(data[i]>>4)];
hex[(i<<1)+1] = tbl[0xF&(data[i])];
}
hex[40] = 0;
gt_log("DUMP(%zu): %s\n", size, hex);
}
static int gt_setup_secretkey (struct crypto_ctx *ctx, char *keyfile)
{
const size_t size = sizeof(ctx->skey);
byte_set(ctx->skey, 1, size);
if (!keyfile)
return 0;
int fd;
do {
fd = open(keyfile, O_RDONLY|O_CLOEXEC);
} while (fd==-1 && errno==EINTR);
if (fd==-1) {
perror("open keyfile");
return -1;
}
if (fd_read_all(fd, ctx->skey, size)!=size) {
gt_log("unable to read secret key in `%s'\n", keyfile);
close(fd);
return -1;
}
close(fd);
return 0;
}
static int gt_setup_crypto (struct crypto_ctx *ctx, int fd, int listener)
{
const size_t nonce_size = crypto_aead_aes256gcm_NPUBBYTES;
const size_t public_size = crypto_scalarmult_SCALARBYTES;
const size_t hash_size = crypto_generichash_BYTES;
const size_t size = nonce_size + public_size + hash_size;
uint8_t secret[crypto_scalarmult_SCALARBYTES];
uint8_t shared[crypto_scalarmult_BYTES];
uint8_t key[crypto_aead_aes256gcm_KEYBYTES];
uint8_t data_r[size], data_w[size];
uint8_t auth_r[hash_size], auth_w[hash_size];
uint8_t hash[hash_size];
crypto_generichash_state state;
randombytes_buf(data_w, nonce_size);
randombytes_buf(secret, sizeof(secret));
crypto_scalarmult_base(&data_w[nonce_size], secret);
crypto_generichash(&data_w[size-hash_size], hash_size,
data_w, size-hash_size, ctx->skey, sizeof(ctx->skey));
if (!listener && fd_write_all(fd, data_w, size)!=size)
return -1;
if (fd_read_all(fd, data_r, size)!=size)
return -1;
crypto_generichash(hash, hash_size,
data_r, size-hash_size, ctx->skey, sizeof(ctx->skey));
if (sodium_memcmp(&data_r[size-hash_size], hash, hash_size))
return -2;
if (listener && fd_write_all(fd, data_w, size)!=size)
return -1;
crypto_generichash(auth_w, hash_size,
data_r, size, ctx->skey, sizeof(ctx->skey));
if (fd_write_all(fd, auth_w, hash_size)!=hash_size)
return -1;
if (fd_read_all(fd, auth_r, hash_size)!=hash_size)
return -1;
crypto_generichash(hash, hash_size,
data_w, size, ctx->skey, sizeof(ctx->skey));
if (sodium_memcmp(auth_r, hash, hash_size))
return -2;
if (crypto_scalarmult(shared, secret, &data_r[nonce_size]))
return -2;
crypto_generichash_init(&state, ctx->skey, sizeof(ctx->skey), sizeof(key));
crypto_generichash_update(&state, shared, sizeof(shared));
crypto_generichash_update(&state, data_r, size);
crypto_generichash_update(&state, data_w, size);
crypto_generichash_final(&state, key, sizeof(key));
crypto_aead_aes256gcm_beforenm(&ctx->read.state, key);
crypto_generichash_init(&state, ctx->skey, sizeof(ctx->skey), sizeof(key));
crypto_generichash_update(&state, shared, sizeof(shared));
crypto_generichash_update(&state, data_w, size);
crypto_generichash_update(&state, data_r, size);
crypto_generichash_final(&state, key, sizeof(key));
crypto_aead_aes256gcm_beforenm(&ctx->write.state, key);
sodium_memzero(secret, sizeof(secret));
sodium_memzero(shared, sizeof(shared));
sodium_memzero(key, sizeof(key));
byte_cpy(ctx->read.nonce, data_r, nonce_size);
byte_cpy(ctx->write.nonce, data_w, nonce_size);
return 0;
}
int main (int argc, char **argv)
{
gt_set_signal();
char *host = NULL;
char *port = "5000";
char *dev = PACKAGE_NAME;
char *keyfile = NULL;
char *congestion = NULL;
long buffer_size = GT_BUFFER_SIZE;
long ka_count = -1;
long ka_idle = -1;
long ka_interval = -1;
long retry_count = 0;
long retry_slope = 1000;
long retry_const = 0;
long retry_limit = 1000000;
struct option ka_opts[] = {
{ "count", &ka_count, option_long },
{ "idle", &ka_idle, option_long },
{ "interval", &ka_interval, option_long },
{ NULL },
};
struct option daemon_opts[] = {
{ "fake", NULL, option_option },
{ NULL },
};
struct option retry_opts[] = {
{ "count", &retry_count, option_long },
{ "slope", &retry_slope, option_long },
{ "const", &retry_const, option_long },
{ "limit", &retry_limit, option_long },
{ NULL },
};
struct option opts[] = {
{ "listener", NULL, option_option },
{ "host", &host, option_str },
{ "port", &port, option_str },
{ "dev", &dev, option_str },
{ "keyfile", &keyfile, option_str },
{ "congestion", &congestion, option_str },
{ "delay", NULL, option_option },
{ "multiqueue", NULL, option_option },
{ "keepalive", ka_opts, option_option },
{ "buffer-size", &buffer_size, option_long },
{ "noquickack", NULL, option_option },
{ "retry", &retry_opts, option_option },
{ "daemon", &daemon_opts, option_option },
{ "trap", NULL, option_option },
{ "version", NULL, option_option },
{ NULL },
};
if (option(opts, argc, argv))
return 1;
if (option_is_set(opts, "version")) {
gt_print(PACKAGE_STRING"\n");
return 0;
}
const int listener = option_is_set(opts, "listener");
const int delay = option_is_set(opts, "delay");
const int keepalive = option_is_set(opts, "keepalive");
const int noquickack = option_is_set(opts, "noquickack");
if (buffer_size < 2048) {
buffer_size = 2048;
gt_log("buffer size must be greater than 2048!\n");
}
if (sodium_init()==-1) {
gt_log("libsodium initialization has failed!\n");
return 1;
}
if (!crypto_aead_aes256gcm_is_available()) {
gt_na("AES-256-GCM");
return 1;
}
struct crypto_ctx ctx;
if (gt_setup_secretkey(&ctx, keyfile))
return 1;
struct addrinfo *ai = ai_create(host, port, listener);
if (!ai)
return 1;
struct fdbuf tun = { .fd = -1 };
struct fdbuf sock = { .fd = -1 };
tun.fd = tun_create(dev, option_is_set(opts, "multiqueue"));
if (tun.fd==-1)
return 1;
struct blk *blks = calloc(256, sizeof(struct blk));
size_t blk_count = 0;
uint8_t blk_read = 0;
uint8_t blk_write = 0;
if (!blks)
return 1;
fd_set_nonblock(tun.fd);
buffer_setup(&tun.write, NULL, GT_TUNW_SIZE);
buffer_setup(&tun.read, NULL, GT_TUNR_SIZE);
buffer_setup(&sock.write, NULL, buffer_size);
buffer_setup(&sock.read, NULL, buffer_size);
int fd = -1;
if (listener) {
fd = sk_create(ai, sk_listen);
if (fd==-1)
return 1;
}
if (option_is_set(opts, "daemon")) {
switch (fork()) {
case -1:
perror("fork");
return 1;
case 0:
if (option_is_set(daemon_opts, "fake")) {
gt_log("running in fake daemon mode\n");
} else if (setsid()==-1) {
perror("setsid");
}
break;
default:
_exit(0);
}
}
long retry = 0;
while (!gt_close) {
sock.fd = listener?sk_accept(fd):sk_create(ai, sk_connect);
if (sock.fd==-1) {
if (retry<LONG_MAX)
retry++;
long usec = retry*retry_slope+retry_const;
if (retry_count>=0 && retry>=retry_count) {
gt_log("couldn't %s (%d attempt%s)\n",
listener?"listen":"connect",
(int)retry, (retry>1)?"s":"");
break;
}
if (usec>retry_limit)
usec = retry_limit;
if (usec<=0)
usec = 0;
if (usleep(usec)==-1 && errno==EINVAL)
sleep(usec/1000000);
continue;
}
char *sockname = sk_get_name(sock.fd);
if (!sockname) {
close(sock.fd);
continue;
}
gt_log("%s: connected\n", sockname);
fd_set_nonblock(sock.fd);
sk_set_int(sock.fd, sk_nodelay, !delay);
sk_set_int(sock.fd, sk_keepalive, keepalive);
if (keepalive) {
if (ka_count>=0 && ka_count<=INT_MAX)
sk_set_int(sock.fd, sk_keepcnt, ka_count);
if (ka_idle>=0 && ka_idle<=INT_MAX)
sk_set_int(sock.fd, sk_keepidle, ka_idle);
if (ka_interval>=0 && ka_interval<=INT_MAX)
sk_set_int(sock.fd, sk_keepintvl, ka_interval);
}
sk_set(sock.fd, sk_congestion, congestion, str_len(congestion));
switch (gt_setup_crypto(&ctx, sock.fd, listener)) {
case -2:
gt_log("%s: key exchange could not be verified!\n", sockname);
goto restart;
case -1:
gt_log("%s: key exchange failed\n", sockname);
goto restart;
default:
break;
}
retry = 0;
if (option_is_set(opts, "trap"))
kill(0, SIGUSR2);
gt_log("%s: running\n", sockname);
fd_set rfds;
FD_ZERO(&rfds);
int stop_loop = 0;
buffer_format(&sock.write);
buffer_format(&sock.read);
while (1) {
if _0_(gt_close)
stop_loop |= 1;
if _0_(stop_loop) {
if (((stop_loop&(1<<2)) || !buffer_read_size(&sock.write)) &&
((stop_loop&(1<<1)) || !buffer_read_size(&sock.read)))
goto restart;
FD_CLR(tun.fd, &rfds);
} else {
if (!blks[blk_write].size) {
FD_SET(tun.fd, &rfds);
} else {
FD_CLR(tun.fd, &rfds);
}
}
buffer_shift(&sock.read);
if (buffer_write_size(&sock.read)) {
FD_SET(sock.fd, &rfds);
} else {
FD_CLR(sock.fd, &rfds);
}
struct timeval timeout = {
.tv_usec = 1000,
};
if _0_(select(sock.fd+1, &rfds, NULL, NULL, &timeout)==-1) {
if (errno==EINTR)
continue;
perror("select");
return 1;
}
// TODO
// struct timeval now;
// gettimeofday(&now, NULL);
#ifdef TCP_INFO
if _0_(gt_info) {
struct tcp_info ti;
if (sk_get_info(sock.fd, &ti))
print_tcp_info(sockname, &ti);
gt_info = 0;
}
#endif
if (FD_ISSET(tun.fd, &rfds)) {
while (!blks[blk_write].size) {
uint8_t *data = blks[blk_write].data;
const ssize_t r = tun_read(tun.fd, data, GT_MTU_MAX);
if (r<=0) {
gt_close |= !r;
break;
}
const ssize_t ip_size = ip_get_size(data, GT_MTU_MAX);
if _0_(ip_size<=0)
continue;
if _0_(ip_size!=r) {
dump_ip_header(data, r);
if (r>ip_size)
continue;
ip_set_size(data, r);
}
blks[blk_write++].size = r;
blk_count++;
}
}
while (1) {
buffer_shift(&tun.read);
if _0_(!stop_loop) {
for (; blk_count; blk_read++) {
const size_t size = blks[blk_read].size;
if (!size || buffer_write_size(&tun.read)<size)
break;
byte_cpy(tun.read.write, blks[blk_read].data, size);
tun.read.write += size;
blks[blk_read].size = 0;
blk_count--;
}
gt_encrypt(&ctx, &sock.write, &tun.read);
}
if (!buffer_read_size(&sock.write))
break;
const ssize_t r = fd_write(sock.fd, sock.write.read,
buffer_read_size(&sock.write));
if (r>0) {
sock.write.read += r;
} else {
if (!r)
stop_loop |= (1<<2);
break;
}
}
if _0_(stop_loop && !buffer_read_size(&sock.write)) {
if (!(stop_loop&(1<<2))) {
stop_loop |= (1<<2);
shutdown(sock.fd, SHUT_WR);
gt_log("%s: shutdown\n", sockname);
}
}
buffer_shift(&sock.write);
if (FD_ISSET(sock.fd, &rfds)) {
if (noquickack)
sk_set_int(sock.fd, sk_quickack, 0);
const ssize_t r = fd_read(sock.fd, sock.read.write,
buffer_write_size(&sock.read));
if (r>0) {
sock.read.write += r;
} else if (!r) {
stop_loop |= (1<<1);
}
}
while (1) {
buffer_shift(&tun.write);
if _0_(gt_decrypt(&ctx, &tun.write, &sock.read)) {
gt_log("%s: message could not be verified!\n", sockname);
goto restart;
}
size_t size = buffer_read_size(&tun.write);
ssize_t ip_size = ip_get_size(tun.write.read, size);
if _0_(!ip_size) {
gt_log("%s: bad packet!\n", sockname);
goto restart;
}
if (ip_size<0 || (size_t)ip_size>size)
break;
ssize_t r = tun_write(tun.fd, tun.write.read, ip_size);
if (r>0) {
tun.write.read += r;
} else {
gt_close |= !r;
break;
}
}
}
restart:
if (sockname) {
free(sockname);
sockname = NULL;
}
if (sock.fd!=-1) {
close(sock.fd);
sock.fd = -1;
}
}
freeaddrinfo(ai);
free(blks);
free(sock.write.data);
free(sock.read.data);
free(tun.write.data);
free(tun.read.data);
return 0;
}