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redsocks.c
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/* redsocks - transparent TCP-to-proxy redirector
* Copyright (C) 2007-2018 Leonid Evdokimov <[email protected]>
*
* 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
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
#include <sys/types.h>
#include <sys/utsname.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <time.h>
#include <errno.h>
#include <assert.h>
#include <fcntl.h>
#include <event.h>
#include "list.h"
#include "parser.h"
#include "log.h"
#include "main.h"
#include "base.h"
#include "redsocks.h"
#include "utils.h"
#include "libevent-compat.h"
#include "tls.h"
#include "http_parser.h"
#define MINIMUM_HOST_READ (10)
#define MAXIMUM_HOST_READ (0)
struct http_parser_data {
const char *last_header_field;
const char *http_host;
size_t http_host_length;
};
typedef enum _redsocks_hostname_read_rc {
SUCCESS = 0,
DATA_MISSING = 1,
FATAL_ERROR = 2,
} redsocks_hostname_read_rc;
#define REDSOCKS_RELAY_HALFBUFF 4096
enum pump_state_t {
pump_active = -1,
pump_MAX = 0,
};
static const char *redsocks_event_str(unsigned short what);
static int redsocks_start_bufferpump(redsocks_client *client);
static int redsocks_start_splicepump(redsocks_client *client);
static void redsocks_conn_list_del(redsocks_client *client);
extern relay_subsys http_connect_subsys;
extern relay_subsys http_relay_subsys;
extern relay_subsys socks4_subsys;
extern relay_subsys socks5_subsys;
static relay_subsys *relay_subsystems[] =
{
&http_connect_subsys,
&http_relay_subsys,
&socks4_subsys,
&socks5_subsys,
};
static list_head instances = LIST_HEAD_INIT(instances);
// Managing connection pressure.
static uint32_t redsocks_conn;
static uint32_t accept_backoff_ms;
static struct event accept_backoff_ev;
static parser_entry redsocks_entries[] =
{
{ .key = "local_ip", .type = pt_in_addr },
{ .key = "local_port", .type = pt_uint16 },
{ .key = "ip", .type = pt_in_addr },
{ .key = "port", .type = pt_uint16 },
{ .key = "type", .type = pt_pchar },
{ .key = "login", .type = pt_pchar },
{ .key = "password", .type = pt_pchar },
{ .key = "listenq", .type = pt_uint16 },
{ .key = "parse_sni_host", .type = pt_bool },
{ .key = "parse_http_host", .type = pt_bool },
{ .key = "splice", .type = pt_bool },
{ .key = "disclose_src", .type = pt_disclose_src },
{ .key = "on_proxy_fail", .type = pt_on_proxy_fail },
{ }
};
static bool is_splice_good()
{
struct utsname u;
if (uname(&u) != 0) {
return false;
}
unsigned long int v[4] = { 0, 0, 0, 0 };
char *rel = u.release;
for (int i = 0; i < SIZEOF_ARRAY(v); ++i) {
v[i] = strtoul(rel, &rel, 0);
while (*rel && !isdigit(*rel))
++rel;
}
// haproxy assumes that splice "works" for 2.6.27.13+
return (v[0] > 2) ||
(v[0] == 2 && v[1] > 6) ||
(v[0] == 2 && v[1] == 6 && v[2] > 27) ||
(v[0] == 2 && v[1] == 6 && v[2] == 27 && v[3] >= 13);
}
static int redsocks_onenter(parser_section *section)
{
// FIXME: find proper way to calulate instance_payload_len
int instance_payload_len = 0;
relay_subsys **ss;
FOREACH(ss, relay_subsystems)
if (instance_payload_len < (*ss)->instance_payload_len)
instance_payload_len = (*ss)->instance_payload_len;
redsocks_instance *instance = calloc(1, sizeof(*instance) + instance_payload_len);
if (!instance) {
parser_error(section->context, "Not enough memory");
return -1;
}
INIT_LIST_HEAD(&instance->list);
INIT_LIST_HEAD(&instance->clients);
instance->config.bindaddr.sin_family = AF_INET;
instance->config.bindaddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
instance->config.relayaddr.sin_family = AF_INET;
instance->config.relayaddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
/* Default value can be checked in run-time, but I doubt anyone needs that.
* Linux: sysctl net.core.somaxconn
* FreeBSD: sysctl kern.ipc.somaxconn */
instance->config.listenq = SOMAXCONN;
instance->config.use_splice = is_splice_good();
instance->config.disclose_src = DISCLOSE_NONE;
instance->config.on_proxy_fail = ONFAIL_CLOSE;
for (parser_entry *entry = §ion->entries[0]; entry->key; entry++)
entry->addr =
(strcmp(entry->key, "local_ip") == 0) ? (void*)&instance->config.bindaddr.sin_addr :
(strcmp(entry->key, "local_port") == 0) ? (void*)&instance->config.bindaddr.sin_port :
(strcmp(entry->key, "ip") == 0) ? (void*)&instance->config.relayaddr.sin_addr :
(strcmp(entry->key, "port") == 0) ? (void*)&instance->config.relayaddr.sin_port :
(strcmp(entry->key, "type") == 0) ? (void*)&instance->config.type :
(strcmp(entry->key, "login") == 0) ? (void*)&instance->config.login :
(strcmp(entry->key, "password") == 0) ? (void*)&instance->config.password :
(strcmp(entry->key, "listenq") == 0) ? (void*)&instance->config.listenq :
(strcmp(entry->key, "parse_sni_host") == 0) ? (void*)&instance->config.parse_sni_host :
(strcmp(entry->key, "parse_http_host") == 0) ? (void*)&instance->config.parse_http_host :
(strcmp(entry->key, "splice") == 0) ? (void*)&instance->config.use_splice :
(strcmp(entry->key, "disclose_src") == 0) ? (void*)&instance->config.disclose_src :
(strcmp(entry->key, "on_proxy_fail") == 0) ? (void*)&instance->config.on_proxy_fail :
NULL;
section->data = instance;
return 0;
}
static int redsocks_onexit(parser_section *section)
{
/* FIXME: Rewrite in bullet-proof style. There are memory leaks if config
* file is not correct, so correct on-the-fly config reloading is
* currently impossible.
*/
redsocks_instance *instance = section->data;
section->data = NULL;
for (parser_entry *entry = §ion->entries[0]; entry->key; entry++)
entry->addr = NULL;
instance->config.bindaddr.sin_port = htons(instance->config.bindaddr.sin_port);
instance->config.relayaddr.sin_port = htons(instance->config.relayaddr.sin_port);
if (instance->config.type) {
relay_subsys **ss;
FOREACH(ss, relay_subsystems) {
if (!strcmp((*ss)->name, instance->config.type)) {
instance->relay_ss = *ss;
list_add(&instance->list, &instances);
break;
}
}
if (!instance->relay_ss) {
parser_error(section->context, "invalid `type` <%s> for redsocks", instance->config.type);
return -1;
}
}
else {
parser_error(section->context, "no `type` for redsocks");
return -1;
}
if (instance->config.disclose_src != DISCLOSE_NONE && instance->relay_ss != &http_connect_subsys) {
parser_error(section->context, "only `http-connect` supports `disclose_src` at the moment");
return -1;
}
if (instance->config.on_proxy_fail != ONFAIL_CLOSE && instance->relay_ss != &http_connect_subsys) {
parser_error(section->context, "only `http-connect` supports `on_proxy_fail` at the moment");
return -1;
}
return 0;
}
static parser_section redsocks_conf_section =
{
.name = "redsocks",
.entries = redsocks_entries,
.onenter = redsocks_onenter,
.onexit = redsocks_onexit
};
void redsocks_log_write_plain(
const char *file, int line, const char *func, int do_errno,
const struct sockaddr_in *clientaddr, const struct sockaddr_in *destaddr,
int priority, const char *orig_fmt, ...
) {
if (!should_log(priority))
return;
int saved_errno = errno;
struct evbuffer *fmt = evbuffer_new();
va_list ap;
char clientaddr_str[RED_INET_ADDRSTRLEN], destaddr_str[RED_INET_ADDRSTRLEN];
if (!fmt) {
log_errno(LOG_ERR, "evbuffer_new()");
// no return, as I have to call va_start/va_end
}
if (fmt) {
evbuffer_add_printf(fmt, "[%s->%s]: %s",
red_inet_ntop(clientaddr, clientaddr_str, sizeof(clientaddr_str)),
red_inet_ntop(destaddr, destaddr_str, sizeof(destaddr_str)),
orig_fmt);
}
va_start(ap, orig_fmt);
if (fmt) {
errno = saved_errno;
_log_vwrite(file, line, func, do_errno, priority, (const char*)evbuffer_pullup(fmt, -1), ap);
evbuffer_free(fmt);
}
va_end(ap);
}
void redsocks_touch_client(redsocks_client *client)
{
redsocks_gettimeofday(&client->last_event);
}
static bool shut_both(redsocks_client *client)
{
return client->relay_evshut == (EV_READ|EV_WRITE) && client->client_evshut == (EV_READ|EV_WRITE);
}
static int bufprio(redsocks_client *client, struct bufferevent *buffev)
{
// client errors are logged with LOG_INFO, server errors with LOG_NOTICE
return (buffev == client->client) ? LOG_INFO : LOG_NOTICE;
}
static const char* bufname(redsocks_client *client, struct bufferevent *buf)
{
assert(buf == client->client || buf == client->relay);
return buf == client->client ? "client" : "relay";
}
static void redsocks_relay_readcb(redsocks_client *client, struct bufferevent *from, struct bufferevent *to)
{
if (evbuffer_get_length(to->output) < to->wm_write.high) {
if (bufferevent_write_buffer(to, from->input) == -1)
redsocks_log_errno(client, LOG_ERR, "bufferevent_write_buffer");
}
else {
if (bufferevent_get_enabled(from) & EV_READ) {
redsocks_log_error(client, LOG_DEBUG, "backpressure: bufferevent_disable(%s, EV_READ)", bufname(client, from));
if (bufferevent_disable(from, EV_READ) == -1)
redsocks_log_errno(client, LOG_ERR, "bufferevent_disable");
}
}
}
static void redsocks_relay_writecb(redsocks_client *client, struct bufferevent *from, struct bufferevent *to)
{
assert(from == client->client || from == client->relay);
char from_eof = (from == client->client ? client->client_evshut : client->relay_evshut) & EV_READ;
if (evbuffer_get_length(from->input) == 0 && from_eof) {
redsocks_shutdown(client, to, SHUT_WR);
}
else if (evbuffer_get_length(to->output) < to->wm_write.high) {
if (bufferevent_write_buffer(to, from->input) == -1)
redsocks_log_errno(client, LOG_ERR, "bufferevent_write_buffer");
if (!from_eof && !(bufferevent_get_enabled(from) & EV_READ)) {
redsocks_log_error(client, LOG_DEBUG, "backpressure: bufferevent_enable(%s, EV_READ)", bufname(client, from));
if (bufferevent_enable(from, EV_READ) == -1)
redsocks_log_errno(client, LOG_ERR, "bufferevent_enable");
}
}
}
static void redsocks_relay_relayreadcb(struct bufferevent *from, void *_client)
{
redsocks_client *client = _client;
redsocks_touch_client(client);
redsocks_relay_readcb(client, client->relay, client->client);
}
static void redsocks_relay_relaywritecb(struct bufferevent *to, void *_client)
{
redsocks_client *client = _client;
redsocks_touch_client(client);
redsocks_relay_writecb(client, client->client, client->relay);
}
static void redsocks_relay_clientreadcb(struct bufferevent *from, void *_client)
{
redsocks_client *client = _client;
redsocks_touch_client(client);
redsocks_relay_readcb(client, client->client, client->relay);
}
static void redsocks_relay_clientwritecb(struct bufferevent *to, void *_client)
{
redsocks_client *client = _client;
redsocks_touch_client(client);
redsocks_relay_writecb(client, client->relay, client->client);
}
void redsocks_start_relay(redsocks_client *client)
{
if (client->instance->relay_ss->fini)
client->instance->relay_ss->fini(client);
client->state = pump_active;
int error = ((client->instance->config.use_splice) ? redsocks_start_splicepump : redsocks_start_bufferpump)(client);
if (!error)
redsocks_log_error(client, LOG_DEBUG, "data relaying started");
else
redsocks_drop_client(client);
}
static int redsocks_start_bufferpump(redsocks_client *client)
{
// wm_write.high is respected by libevent-2.0.22 only for ssl and filters,
// so it's implemented in redsocks callbacks. wm_read.high works as expected.
bufferevent_setwatermark(client->client, EV_READ|EV_WRITE, 0, REDSOCKS_RELAY_HALFBUFF);
bufferevent_setwatermark(client->relay, EV_READ|EV_WRITE, 0, REDSOCKS_RELAY_HALFBUFF);
client->client->readcb = redsocks_relay_clientreadcb;
client->client->writecb = redsocks_relay_clientwritecb;
client->relay->readcb = redsocks_relay_relayreadcb;
client->relay->writecb = redsocks_relay_relaywritecb;
int error = bufferevent_enable(client->client, (EV_READ|EV_WRITE) & ~(client->client_evshut));
if (!error)
error = bufferevent_enable(client->relay, (EV_READ|EV_WRITE) & ~(client->relay_evshut));
if (error)
redsocks_log_errno(client, LOG_ERR, "bufferevent_enable");
return error;
}
static int pipeprio(redsocks_pump *pump, int fd)
{
// client errors are logged with LOG_INFO, server errors with LOG_NOTICE
return (fd == event_get_fd(&pump->client_read)) ? LOG_INFO : LOG_NOTICE;
}
static const char* pipename(redsocks_pump *pump, int fd)
{
return (fd == event_get_fd(&pump->client_read)) ? "client" : "relay";
}
static void bufferevent_free_unused(struct bufferevent **p) {
if (*p && !evbuffer_get_length((*p)->input) && !evbuffer_get_length((*p)->output)) {
bufferevent_free(*p);
*p = NULL;
}
}
static bool would_block(int e) {
return e == EAGAIN || e == EWOULDBLOCK;
}
typedef struct redsplice_write_ctx_t {
// drain ebsrc[0], ebsrc[1], pisrc in that order
struct evbuffer *ebsrc[2];
splice_pipe *pisrc;
struct event *evsrc;
struct event *evdst;
const evshut_t *shut_src;
evshut_t *shut_dst;
} redsplice_write_ctx;
static void redsplice_write_cb(redsocks_pump *pump, redsplice_write_ctx *c, int out)
{
bool has_data = false; // there is some pending data to be written
bool can_write = true; // socket SEEMS TO BE writable
// short write -- goto read/write management
// write error -- drop client alltogether
// full write -- take next buffer
// got EOF & no data -- relay EOF
for (int i = 0; i < SIZEOF_ARRAY(c->ebsrc); ++i) {
struct evbuffer *ebsrc = c->ebsrc[i];
if (ebsrc) {
const size_t avail = evbuffer_get_length(ebsrc);
has_data = !!avail;
if (avail) {
const ssize_t sent = evbuffer_write(ebsrc, out);
if (sent == -1) {
if (would_block(errno)) { // short (zero) write
can_write = false;
goto decide;
} else {
redsocks_log_errno(&pump->c, pipeprio(pump, out), "evbuffer_write(to %s, %zu)", pipename(pump, out), avail);
redsocks_drop_client(&pump->c);
return;
}
} else if (avail == sent) {
has_data = false; // unless stated otherwise
} else { // short write
can_write = false;
goto decide;
}
}
}
}
do {
has_data = !!c->pisrc->size;
const size_t avail = c->pisrc->size;
if (avail) {
const ssize_t sent = splice(c->pisrc->read, NULL, out, NULL, avail, SPLICE_F_MOVE|SPLICE_F_NONBLOCK);
if (sent == -1) {
if (would_block(errno)) { // short (zero) write
can_write = false;
goto decide;
} else {
redsocks_log_errno(&pump->c, pipeprio(pump, out), "splice(to %s)", pipename(pump, out));
redsocks_drop_client(&pump->c);
return;
}
} else {
c->pisrc->size -= sent;
if (avail == sent) {
has_data = false;
} else { // short write
can_write = false;
goto decide;
}
}
}
} while (0);
decide:
if (!has_data && (*c->shut_src & EV_READ) && !(*c->shut_dst & EV_WRITE)) {
if (shutdown(out, SHUT_WR) != 0) {
redsocks_log_errno(&pump->c, LOG_ERR, "shutdown(%s, SHUT_WR)", pipename(pump, out));
}
*c->shut_dst |= EV_WRITE;
can_write = false;
assert(!c->pisrc->size);
redsocks_close(c->pisrc->read);
c->pisrc->read = -1;
redsocks_close(c->pisrc->write);
c->pisrc->write = -1;
if (shut_both(&pump->c)) {
redsocks_drop_client(&pump->c);
return;
}
}
assert(!(can_write && has_data)); // incomplete write to writable socket
if (!can_write && has_data) {
if (event_pending(c->evsrc, EV_READ, NULL))
redsocks_log_error(&pump->c, LOG_DEBUG, "backpressure: event_del(%s_read)", pipename(pump, event_get_fd(c->evsrc)));
redsocks_event_del(&pump->c, c->evsrc);
redsocks_event_add(&pump->c, c->evdst);
} else if (can_write && !has_data) {
if (!event_pending(c->evsrc, EV_READ, NULL))
redsocks_log_error(&pump->c, LOG_DEBUG, "backpressure: event_add(%s_read)", pipename(pump, event_get_fd(c->evsrc)));
redsocks_event_add(&pump->c, c->evsrc);
redsocks_event_del(&pump->c, c->evdst);
} else if (!can_write && !has_data) { // something like EOF
redsocks_event_del(&pump->c, c->evsrc);
redsocks_event_del(&pump->c, c->evdst);
}
}
typedef struct redsplice_read_ctx_t {
splice_pipe *dst;
struct event *evsrc;
struct event *evdst;
evshut_t *shut_src;
} redsplice_read_ctx;
static void redsplice_read_cb(redsocks_pump *pump, redsplice_read_ctx *c, int in)
{
const size_t pipesize = 1048576; // some default value from fs.pipe-max-size
const ssize_t got = splice(in, NULL, c->dst->write, NULL, pipesize, SPLICE_F_MOVE|SPLICE_F_NONBLOCK);
if (got == -1) {
if (would_block(errno)) {
// there is data at `in', but pipe is full
if (!event_pending(c->evsrc, EV_READ, NULL))
redsocks_log_error(&pump->c, LOG_DEBUG, "backpressure: event_del(%s_read)", pipename(pump, event_get_fd(c->evsrc)));
redsocks_event_del(&pump->c, c->evsrc);
} else {
redsocks_log_errno(&pump->c, pipeprio(pump, in), "splice(from %s)", pipename(pump, in));
redsocks_drop_client(&pump->c);
}
return;
}
if (got == 0) { // got EOF
if (shutdown(in, SHUT_RD) != 0) {
if (errno != ENOTCONN) { // do not log common case for splice()
redsocks_log_errno(&pump->c, LOG_DEBUG, "shutdown(%s, SHUT_RD) after EOF", pipename(pump, in));
}
}
*c->shut_src |= EV_READ;
redsocks_event_del(&pump->c, c->evsrc);
} else {
c->dst->size += got;
}
event_active(c->evdst, EV_WRITE, 0);
}
static void redsocks_touch_pump(redsocks_pump *pump)
{
redsocks_touch_client(&pump->c);
bufferevent_free_unused(&pump->c.client);
bufferevent_free_unused(&pump->c.relay);
}
static void redsplice_relay_read(int fd, short what, void *_pump)
{
redsocks_pump *pump = _pump;
assert(fd == event_get_fd(&pump->relay_read) && (what & EV_READ));
redsocks_touch_pump(pump);
redsplice_read_ctx c = {
.dst = &pump->reply,
.evsrc = &pump->relay_read,
.evdst = &pump->client_write,
.shut_src = &pump->c.relay_evshut,
};
redsplice_read_cb(pump, &c, fd);
}
static void redsplice_client_read(int fd, short what, void *_pump)
{
redsocks_pump *pump = _pump;
assert(fd == event_get_fd(&pump->client_read) && (what & EV_READ));
redsocks_touch_pump(pump);
redsplice_read_ctx c = {
.dst = &pump->request,
.evsrc = &pump->client_read,
.evdst = &pump->relay_write,
.shut_src = &pump->c.client_evshut,
};
redsplice_read_cb(pump, &c, fd);
}
static void redsplice_relay_write(int fd, short what, void *_pump)
{
redsocks_pump *pump = _pump;
assert(fd == event_get_fd(&pump->relay_write) && (what & EV_WRITE));
redsocks_touch_pump(pump);
redsplice_write_ctx c = {
.ebsrc = {
pump->c.relay ? pump->c.relay->output : NULL,
pump->c.client ? pump->c.client->input : NULL,
},
.pisrc = &pump->request,
.evsrc = &pump->client_read,
.evdst = &pump->relay_write,
.shut_src = &pump->c.client_evshut,
.shut_dst = &pump->c.relay_evshut,
};
redsplice_write_cb(pump, &c, fd);
}
static void redsplice_client_write(int fd, short what, void *_pump)
{
redsocks_pump *pump = _pump;
assert(fd == event_get_fd(&pump->client_write) && (what & EV_WRITE));
redsocks_touch_pump(pump);
redsplice_write_ctx c = {
.ebsrc = {
pump->c.client ? pump->c.client->output : NULL,
pump->c.relay ? pump->c.relay->input : NULL,
},
.pisrc = &pump->reply,
.evsrc = &pump->relay_read,
.evdst = &pump->client_write,
.shut_src = &pump->c.relay_evshut,
.shut_dst = &pump->c.client_evshut,
};
redsplice_write_cb(pump, &c, fd);
}
static int redsocks_start_splicepump(redsocks_client *client)
{
int error = bufferevent_disable(client->client, EV_READ|EV_WRITE);
if (!error)
error = bufferevent_disable(client->relay, EV_READ|EV_WRITE);
if (error) {
redsocks_log_errno(client, LOG_ERR, "bufferevent_disable");
return error;
}
// going to steal this buffers to the socket
evbuffer_unfreeze(client->client->input, 0);
evbuffer_unfreeze(client->client->output, 1);
evbuffer_unfreeze(client->relay->input, 0);
evbuffer_unfreeze(client->relay->output, 1);
redsocks_pump *pump = red_pump(client);
if (!error)
error = pipe2(&pump->request.read, O_NONBLOCK);
if (!error)
error = pipe2(&pump->reply.read, O_NONBLOCK);
if (error) {
redsocks_log_errno(client, LOG_ERR, "pipe2");
return error;
}
struct event_base *base = NULL;
const int relay_fd = bufferevent_getfd(client->relay);
const int client_fd = bufferevent_getfd(client->client);
if (!error)
error = event_assign(&pump->client_read, base, client_fd, EV_READ|EV_PERSIST, redsplice_client_read, pump);
if (!error)
error = event_assign(&pump->client_write, base, client_fd, EV_WRITE|EV_PERSIST, redsplice_client_write, pump);
if (!error)
error = event_assign(&pump->relay_read, base, relay_fd, EV_READ|EV_PERSIST, redsplice_relay_read, pump);
if (!error)
error = event_assign(&pump->relay_write, base, relay_fd, EV_WRITE|EV_PERSIST, redsplice_relay_write, pump);
if (error) {
redsocks_log_errno(client, LOG_ERR, "event_assign");
return error;
}
redsocks_bufferevent_dropfd(client, client->relay);
redsocks_bufferevent_dropfd(client, client->client);
// flush buffers (if any) and enable EV_READ callbacks
event_active(&pump->client_write, EV_WRITE, 0);
event_active(&pump->relay_write, EV_WRITE, 0);
redsocks_event_add(&pump->c, &pump->client_read);
redsocks_event_add(&pump->c, &pump->relay_read);
return 0;
}
static bool has_loopback_destination(redsocks_client *client)
{
const uint32_t net = ntohl(client->destaddr.sin_addr.s_addr) >> 24;
return 0 == memcmp(&client->destaddr.sin_addr, &client->instance->config.relayaddr.sin_addr, sizeof(client->destaddr.sin_addr))
|| net == 127 || net == 0;
}
void redsocks_drop_client(redsocks_client *client)
{
if (shut_both(client)) {
redsocks_log_error(client, LOG_INFO, "connection closed");
} else {
if (has_loopback_destination(client)) {
static time_t last = 0;
const time_t now = redsocks_time(NULL);
if (now - last >= 3600) {
// log this warning once an hour to save some debugging time, OTOH it may be valid traffic in some cases
redsocks_log_error(client, LOG_NOTICE, "client tries to connect to the proxy using proxy! Usual proxy security policy is to drop alike connection");
last = now;
}
}
struct timeval now, idle;
redsocks_gettimeofday(&now); // FIXME: use CLOCK_MONOTONIC
timersub(&now, &client->last_event, &idle);
redsocks_log_error(client, LOG_INFO, "dropping client (%s), relay (%s), idle %ld.%06lds",
redsocks_event_str( (~client->client_evshut) & (EV_READ|EV_WRITE) ),
redsocks_event_str( (~client->relay_evshut) & (EV_READ|EV_WRITE) ),
idle.tv_sec, idle.tv_usec);
}
if (client->instance->relay_ss->fini)
client->instance->relay_ss->fini(client);
if (client->client)
redsocks_bufferevent_free(client->client);
if (client->relay)
redsocks_bufferevent_free(client->relay);
if (client->instance->config.use_splice) {
redsocks_pump *pump = red_pump(client);
if (pump->request.read != -1)
redsocks_close(pump->request.read);
if (pump->request.write != -1)
redsocks_close(pump->request.write);
if (pump->reply.read != -1)
redsocks_close(pump->reply.read);
if (pump->reply.write != -1)
redsocks_close(pump->reply.write);
// redsocks_close MAY log error if some of events was not properly initialized
int fd = -1;
if (event_initialized(&pump->client_read)) {
fd = event_get_fd(&pump->client_read);
redsocks_event_del(&pump->c, &pump->client_read);
}
if (event_initialized(&pump->client_write)) {
redsocks_event_del(&pump->c, &pump->client_write);
}
if (fd != -1)
redsocks_close(fd);
fd = -1;
if (event_initialized(&pump->relay_read)) {
fd = event_get_fd(&pump->relay_read);
redsocks_event_del(&pump->c, &pump->relay_read);
}
if (event_initialized(&pump->relay_write)) {
redsocks_event_del(&pump->c, &pump->relay_write);
}
if (fd != -1) {
redsocks_close(fd);
}
}
redsocks_conn_list_del(client);
if (client->hostname != NULL)
free(client->hostname);
free(client);
}
void redsocks_shutdown(redsocks_client *client, struct bufferevent *buffev, int how)
{
short evhow = 0;
const char *strev, *strhow = NULL, *strevhow = NULL;
unsigned short *pevshut;
assert(how == SHUT_RD || how == SHUT_WR || how == SHUT_RDWR);
assert(buffev == client->client || buffev == client->relay);
assert(event_get_fd(&buffev->ev_read) == event_get_fd(&buffev->ev_write));
if (how == SHUT_RD) {
strhow = "SHUT_RD";
evhow = EV_READ;
strevhow = "EV_READ";
}
else if (how == SHUT_WR) {
strhow = "SHUT_WR";
evhow = EV_WRITE;
strevhow = "EV_WRITE";
}
else if (how == SHUT_RDWR) {
strhow = "SHUT_RDWR";
evhow = EV_READ|EV_WRITE;
strevhow = "EV_READ|EV_WRITE";
}
assert(strhow && strevhow);
strev = bufname(client, buffev);
pevshut = buffev == client->client ? &client->client_evshut : &client->relay_evshut;
// if EV_WRITE is already shut and we're going to shutdown read then
// we're either going to abort data flow (bad behaviour) or confirm EOF
// and in this case socket is already SHUT_RD'ed
if ( !(how == SHUT_RD && (*pevshut & EV_WRITE)) ) {
if (shutdown(event_get_fd(&buffev->ev_read), how) != 0)
redsocks_log_errno(client, LOG_ERR, "shutdown(%s, %s)", strev, strhow);
} else {
redsocks_log_error(client, LOG_DEBUG, "ignored shutdown(%s, %s)", strev, strhow);
}
redsocks_log_error(client, LOG_DEBUG, "shutdown: bufferevent_disable(%s, %s)", strev, strevhow);
if (bufferevent_disable(buffev, evhow) != 0)
redsocks_log_errno(client, LOG_ERR, "bufferevent_disable(%s, %s)", strev, strevhow);
*pevshut |= evhow;
if (shut_both(client)) {
redsocks_log_error(client, LOG_DEBUG, "both client and server disconnected");
redsocks_drop_client(client);
}
}
// I assume that -1 is invalid errno value
static int redsocks_socket_geterrno(redsocks_client *client, struct bufferevent *buffev)
{
int pseudo_errno = red_socket_geterrno(buffev);
if (pseudo_errno == -1) {
redsocks_log_errno(client, LOG_ERR, "red_socket_geterrno");
return -1;
}
return pseudo_errno;
}
static void redsocks_event_error(struct bufferevent *buffev, short what, void *_arg)
{
redsocks_client *client = _arg;
assert(buffev == client->relay || buffev == client->client);
const int bakerrno = errno;
redsocks_touch_client(client);
if (what == (EVBUFFER_READ|EVBUFFER_EOF)) {
struct bufferevent *antiev;
if (buffev == client->relay)
antiev = client->client;
else
antiev = client->relay;
redsocks_shutdown(client, buffev, SHUT_RD);
// If the client has already sent EOF and the pump is not active
// (relay is activating), the code should not shutdown write-pipe.
if (client->state == pump_active && antiev != NULL && evbuffer_get_length(antiev->output) == 0)
redsocks_shutdown(client, antiev, SHUT_WR);
}
else {
const int sockrrno = redsocks_socket_geterrno(client, buffev);
const char *errsrc = "";
if (sockrrno != -1 && sockrrno != 0) {
errno = sockrrno;
errsrc = "socket ";
} else {
errno = bakerrno;
}
redsocks_log_errno(client, bufprio(client, buffev), "%s %serror, code " event_fmt_str,
bufname(client, buffev),
errsrc,
event_fmt(what));
redsocks_drop_client(client);
}
}
int sizes_equal(size_t a, size_t b)
{
return a == b;
}
int sizes_greater_equal(size_t a, size_t b)
{
return a >= b;
}
int redsocks_read_expected(redsocks_client *client, struct evbuffer *input, void *data, size_comparator comparator, size_t expected)
{
size_t len = evbuffer_get_length(input);
if (comparator(len, expected)) {
int read = evbuffer_remove(input, data, expected);
UNUSED(read);
assert(read == expected);
return 0;
}
else {
redsocks_log_error(client, LOG_NOTICE, "Can't get expected amount of data");
redsocks_drop_client(client);
return -1;
}
}
static int redsocks_http_parser_on_header_field(http_parser *parser, const char *at, size_t length)
{
struct http_parser_data *parser_data = (struct http_parser_data *) parser->data;
parser_data->last_header_field = at;
return 0;
}
static int redsocks_http_parser_on_header_value(http_parser *parser, const char *at, size_t length)
{
struct http_parser_data *parser_data = (struct http_parser_data *) parser->data;
if (0 != strncasecmp(parser_data->last_header_field, "host", sizeof("host") - 1)) {
return 0;
}
parser_data->http_host = at;
parser_data->http_host_length = length;
http_parser_pause(parser, 1);
return 0;
}
static int redsocks_peek_buffer(redsocks_client *client, struct bufferevent *buffev, char **peek_buffer, size_t *peek_size)
{
int n = 0, i = 0;
char *read_buffer = NULL;
size_t read_buffer_size = 0;
size_t read_buffer_position = 0;
struct evbuffer_iovec *v = NULL;
n = evbuffer_peek(buffev->input, -1, NULL, NULL, 0);
v = malloc(sizeof(struct evbuffer_iovec) * n);
if (NULL == v) {
redsocks_log_error(client, LOG_ERR, "malloc() error");
goto finish;
}
n = evbuffer_peek(buffev->input, -1, NULL, v, n);
read_buffer_size = 0;
for (i = 0; i < n; i++) {
read_buffer_size += v[i].iov_len;
}
read_buffer = (char *) malloc(read_buffer_size);
if (NULL == read_buffer) {
redsocks_log_error(client, LOG_ERR, "malloc() error");
goto fail;
}
read_buffer_position = 0;
for (i = 0; i < n; i++) {
memcpy(&read_buffer[read_buffer_position], v[i].iov_base, v[i].iov_len);
read_buffer_position += v[i].iov_len;
}
fail:
free(v);
finish:
*peek_buffer = read_buffer;
*peek_size = read_buffer_size;
return 0;
}
static redsocks_hostname_read_rc redsocks_read_sni(redsocks_client *client, char *read_buffer, size_t read_buffer_size, char **hostname)
{
int rc = parse_tls_header(read_buffer, read_buffer_size, hostname);
if (rc >= 0) {
return SUCCESS;
}
/* rc < 0 */
if (rc != -4) {
return DATA_MISSING;
}
/* rc == -4, malloc failure */
return FATAL_ERROR;
}
static redsocks_hostname_read_rc redsocks_read_http_host(redsocks_client *client, char *read_buffer, size_t read_buffer_size, char **hostname)
{
http_parser parser;
http_parser_settings parser_settings;
struct http_parser_data parser_data;
char *temp_hostname = NULL;
int rc = HPE_UNKNOWN;
memset(&parser, 0, sizeof(parser));
memset(&parser_settings, 0, sizeof(parser_settings));
memset(&parser_data, 0, sizeof(parser_data));
http_parser_init(&parser, HTTP_REQUEST);
parser.data = &parser_data;
parser_settings.on_header_field = redsocks_http_parser_on_header_field;
parser_settings.on_header_value = redsocks_http_parser_on_header_value;
rc = http_parser_execute(&parser, &parser_settings, read_buffer, read_buffer_size);
if (rc != read_buffer_size &&