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SSLproxy/pxyconn.c

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/*-
* SSLsplit - transparent SSL/TLS interception
* https://www.roe.ch/SSLsplit
*
* Copyright (c) 2009-2018, Daniel Roethlisberger <daniel@roe.ch>.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "pxyconn.h"
#include "prototcp.h"
#include "protossl.h"
#include "protohttp.h"
#include "protoautossl.h"
#include "protopassthrough.h"
#include "privsep.h"
#include "sys.h"
#include "log.h"
#include "attrib.h"
#include "proc.h"
#include <string.h>
#include <arpa/inet.h>
#include <sys/param.h>
#include <assert.h>
#include <event2/listener.h>
#ifdef HAVE_NETFILTER
#include <glob.h>
#endif /* HAVE_NETFILTER */
/*
* Maximum size of data to buffer per connection direction before
* temporarily stopping to read data from the other end.
*/
#define OUTBUF_LIMIT (128*1024)
/*
* Proxy connection context state, describes a proxy connection
* with source and destination socket bufferevents, SSL context and
* other session state. One of these exists per handled proxy
* connection.
*/
#ifdef HAVE_LOCAL_PROCINFO
/* local process data - filled in iff pid != -1 */
typedef struct pxy_conn_lproc_desc {
struct sockaddr_storage srcaddr;
socklen_t srcaddrlen;
pid_t pid;
uid_t uid;
gid_t gid;
/* derived log strings */
char *exec_path;
char *user;
char *group;
} pxy_conn_lproc_desc_t;
#endif /* HAVE_LOCAL_PROCINFO */
int descriptor_table_size = 0;
// @attention The order of names should match the order in protocol enum
char *protocol_names[] = {
// ERROR = -1
"PASSTHROUGH", // = 0
"HTTP",
"HTTPS",
"POP3",
"POP3S",
"SMTP",
"SMTPS",
"AUTOSSL",
"TCP",
"SSL",
};
static protocol_t NONNULL(1)
pxy_setup_proto(pxy_conn_ctx_t *ctx)
{
ctx->protoctx = malloc(sizeof(proto_ctx_t));
if (!ctx->protoctx) {
return PROTO_ERROR;
}
memset(ctx->protoctx, 0, sizeof(proto_ctx_t));
// Default to tcp
prototcp_setup(ctx);
if (ctx->spec->upgrade) {
return protoautossl_setup(ctx);
} else if (ctx->spec->http) {
if (ctx->spec->ssl) {
return protohttps_setup(ctx);
} else {
return protohttp_setup(ctx);
}
} else if (ctx->spec->pop3) {
if (ctx->spec->ssl) {
return (protossl_setup(ctx) != PROTO_ERROR) ? PROTO_POP3S : PROTO_ERROR;
} else {
return PROTO_POP3;
}
} else if (ctx->spec->smtp) {
if (ctx->spec->ssl) {
return (protossl_setup(ctx) != PROTO_ERROR) ? PROTO_SMTPS : PROTO_ERROR;
} else {
return PROTO_SMTP;
}
} else if (ctx->spec->ssl) {
return protossl_setup(ctx);
} else {
return PROTO_TCP;
}
}
static protocol_t NONNULL(1)
pxy_setup_proto_child(pxy_conn_child_ctx_t *ctx)
{
ctx->protoctx = malloc(sizeof(proto_child_ctx_t));
if (!ctx->protoctx) {
return PROTO_ERROR;
}
memset(ctx->protoctx, 0, sizeof(proto_child_ctx_t));
// Default to tcp
prototcp_setup_child(ctx);
if (ctx->conn->spec->upgrade) {
return protoautossl_setup_child(ctx);
} else if (ctx->conn->spec->http) {
if (ctx->conn->spec->ssl) {
return protohttps_setup_child(ctx);
} else {
return protohttp_setup_child(ctx);
}
} else if (ctx->conn->spec->pop3) {
if (ctx->conn->spec->ssl) {
return (protossl_setup_child(ctx) != PROTO_ERROR) ? PROTO_POP3S : PROTO_ERROR;
} else {
return PROTO_POP3;
}
} else if (ctx->conn->spec->smtp) {
if (ctx->conn->spec->ssl) {
return (protossl_setup_child(ctx) != PROTO_ERROR) ? PROTO_SMTPS : PROTO_ERROR;
} else {
return PROTO_SMTP;
}
} else if (ctx->conn->spec->ssl) {
return protossl_setup_child(ctx);
} else {
return PROTO_TCP;
}
}
static pxy_conn_ctx_t * MALLOC NONNULL(2,3,4)
pxy_conn_ctx_new(evutil_socket_t fd,
pxy_thrmgr_ctx_t *thrmgr,
proxyspec_t *spec, opts_t *opts,
evutil_socket_t clisock)
{
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINEST, "pxy_conn_ctx_new: ENTER, fd=%d\n", fd);
#endif /* DEBUG_PROXY */
pxy_conn_ctx_t *ctx = malloc(sizeof(pxy_conn_ctx_t));
if (!ctx) {
log_err_level_printf(LOG_CRIT, "Error allocating memory\n");
evutil_closesocket(fd);
return NULL;
}
memset(ctx, 0, sizeof(pxy_conn_ctx_t));
ctx->id = thrmgr->conn_count++;
#if defined (DEBUG_PROXY)
log_dbg_level_printf(LOG_DBG_MODE_FINEST, "pxy_conn_ctx_new: id=%llu, fd=%d\n", ctx->id, fd);
#endif /* DEBUG_PROXY */
ctx->type = CONN_TYPE_PARENT;
ctx->fd = fd;
ctx->conn = ctx;
ctx->thrmgr = thrmgr;
ctx->spec = spec;
ctx->protoctx = malloc(sizeof(proto_ctx_t));
if (!ctx->protoctx) {
log_err_level_printf(LOG_CRIT, "Error allocating memory\n");
evutil_closesocket(fd);
free(ctx);
return NULL;
}
memset(ctx->protoctx, 0, sizeof(proto_ctx_t));
ctx->proto = pxy_setup_proto(ctx);
if (ctx->proto == PROTO_ERROR) {
log_err_level_printf(LOG_CRIT, "Error allocating memory\n");
evutil_closesocket(fd);
free(ctx->protoctx);
free(ctx);
return NULL;
}
ctx->opts = opts;
ctx->clisock = clisock;
ctx->ctime = time(NULL);
ctx->atime = ctx->ctime;
ctx->next = NULL;
pxy_thrmgr_attach(ctx);
#ifdef HAVE_LOCAL_PROCINFO
ctx->lproc.pid = -1;
#endif /* HAVE_LOCAL_PROCINFO */
return ctx;
}
static pxy_conn_child_ctx_t * MALLOC NONNULL(2)
pxy_conn_ctx_new_child(evutil_socket_t fd, pxy_conn_ctx_t *conn)
{
assert(conn != NULL);
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINEST, "pxy_conn_ctx_new_child: ENTER, fd=%d\n", fd);
#endif /* DEBUG_PROXY */
pxy_conn_child_ctx_t *ctx = malloc(sizeof(pxy_conn_child_ctx_t));
if (!ctx) {
return NULL;
}
memset(ctx, 0, sizeof(pxy_conn_child_ctx_t));
ctx->type = CONN_TYPE_CHILD;
ctx->fd = fd;
ctx->conn = conn;
ctx->protoctx = malloc(sizeof(proto_ctx_t));
if (!ctx->protoctx) {
log_err_level_printf(LOG_CRIT, "Error allocating memory\n");
evutil_closesocket(fd);
free(ctx);
return NULL;
}
memset(ctx->protoctx, 0, sizeof(proto_ctx_t));
ctx->proto = pxy_setup_proto_child(ctx);
if (ctx->proto == PROTO_ERROR) {
log_err_level_printf(LOG_CRIT, "Error allocating memory\n");
evutil_closesocket(fd);
free(ctx->protoctx);
free(ctx);
return NULL;
}
// @attention Child connections use the parent's event bases, otherwise we would get multithreading issues
pxy_thrmgr_attach_child(conn);
return ctx;
}
static void NONNULL(1)
pxy_conn_ctx_free_child(pxy_conn_child_ctx_t *ctx)
{
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINEST, "pxy_conn_ctx_free_child: ENTER, child fd=%d, fd=%d\n", ctx->fd, ctx->conn->fd);
#endif /* DEBUG_PROXY */
pxy_thrmgr_detach_child(ctx->conn);
// If the proto doesn't have special args, proto_free() callback is NULL
if (ctx->protoctx->proto_free) {
ctx->protoctx->proto_free(ctx);
}
free(ctx->protoctx);
free(ctx);
}
static void NONNULL(1,2)
pxy_conn_remove_child(pxy_conn_child_ctx_t *child, pxy_conn_child_ctx_t **head)
{
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINEST, "pxy_conn_remove_child: ENTER, fd=%d\n", child->fd);
#endif /* DEBUG_PROXY */
if (child->fd == (*head)->fd) {
*head = (*head)->next;
return;
}
pxy_conn_child_ctx_t *current = (*head)->next;
pxy_conn_child_ctx_t *previous = *head;
while (current != NULL && previous != NULL) {
if (child->fd == current->fd) {
previous->next = current->next;
return;
}
previous = current;
current = current->next;
}
return;
}
void
pxy_conn_free_child(pxy_conn_child_ctx_t *ctx)
{
assert(ctx->conn != NULL);
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINEST, "pxy_conn_free_child: ENTER, fd=%d\n", ctx->fd);
#endif /* DEBUG_PROXY */
pxy_conn_desc_t *dst = &ctx->dst;
if (dst->bev) {
ctx->protoctx->bufferevent_free_and_close_fd(dst->bev, ctx->conn);
dst->bev = NULL;
}
pxy_conn_desc_t *src = &ctx->src;
if (src->bev) {
prototcp_bufferevent_free_and_close_fd(src->bev, ctx->conn);
src->bev = NULL;
}
pxy_conn_remove_child(ctx, &ctx->conn->children);
pxy_conn_ctx_free_child(ctx);
}
void
pxy_conn_ctx_free(pxy_conn_ctx_t *ctx, int by_requestor)
{
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINEST, "pxy_conn_ctx_free: ENTER, fd=%d\n", ctx->fd);
#endif /* DEBUG_PROXY */
if (WANT_CONTENT_LOG(ctx) && ctx->logctx) {
if (log_content_close(&ctx->logctx, by_requestor) == -1) {
log_err_level_printf(LOG_WARNING, "Content log close failed\n");
}
}
pxy_thrmgr_detach(ctx);
if (ctx->srchost_str) {
free(ctx->srchost_str);
}
if (ctx->srcport_str) {
free(ctx->srcport_str);
}
if (ctx->dsthost_str) {
free(ctx->dsthost_str);
}
if (ctx->dstport_str) {
free(ctx->dstport_str);
}
#ifdef HAVE_LOCAL_PROCINFO
if (ctx->lproc.exec_path) {
free(ctx->lproc.exec_path);
}
if (ctx->lproc.user) {
free(ctx->lproc.user);
}
if (ctx->lproc.group) {
free(ctx->lproc.group);
}
#endif /* HAVE_LOCAL_PROCINFO */
if (ctx->ev) {
event_free(ctx->ev);
}
if (ctx->sslproxy_header) {
free(ctx->sslproxy_header);
}
// If the proto doesn't have special args, proto_free() callback is NULL
if (ctx->protoctx->proto_free) {
ctx->protoctx->proto_free(ctx);
}
free(ctx->protoctx);
free(ctx);
}
void
pxy_conn_free(pxy_conn_ctx_t *ctx, int by_requestor)
{
#ifdef DEBUG_PROXY
evutil_socket_t child_fd = ctx->child_fd;
log_dbg_level_printf(LOG_DBG_MODE_FINEST, "pxy_conn_free: ENTER, fd=%d, child_fd=%d\n", ctx->fd, child_fd);
#endif /* DEBUG_PROXY */
pxy_conn_desc_t *src = &ctx->src;
if (!src->closed) {
if (src->bev) {
ctx->protoctx->bufferevent_free_and_close_fd(src->bev, ctx);
src->bev = NULL;
} else {
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINE, "pxy_conn_free: evutil_closesocket on NULL src->bev, fd=%d\n", ctx->fd);
#endif /* DEBUG_PROXY */
// @todo src fd may be open, although src.bev is NULL, where do we close the src fd?
evutil_closesocket(ctx->fd);
}
}
pxy_conn_desc_t *srv_dst = &ctx->srv_dst;
if (srv_dst->bev) {
ctx->protoctx->bufferevent_free_and_close_fd(srv_dst->bev, ctx);
srv_dst->bev = NULL;
}
pxy_conn_desc_t *dst = &ctx->dst;
if (dst->bev) {
prototcp_bufferevent_free_and_close_fd(dst->bev, ctx);
dst->bev = NULL;
}
// @attention Free the child ctxs asap, we need their fds
while (ctx->children) {
pxy_conn_free_child(ctx->children);
}
// @attention Parent may be closing before there was any child at all nor was child_evcl ever created
if (ctx->child_evcl) {
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINER, "pxy_conn_free: Freeing child_evcl, child fd=%d, children->fd=%d, fd=%d\n",
ctx->child_fd, ctx->children ? ctx->children->fd : -1, ctx->fd);
#endif /* DEBUG_PROXY */
// @attention child_evcl was created with LEV_OPT_CLOSE_ON_FREE, so do not close ctx->child_fd
evconnlistener_free(ctx->child_evcl);
ctx->child_evcl = NULL;
}
pxy_conn_ctx_free(ctx, by_requestor);
}
void
pxy_log_connect_nonhttp(pxy_conn_ctx_t *ctx)
{
char *msg;
#ifdef HAVE_LOCAL_PROCINFO
char *lpi = NULL;
#endif /* HAVE_LOCAL_PROCINFO */
int rv;
#ifdef HAVE_LOCAL_PROCINFO
if (ctx->opts->lprocinfo) {
rv = asprintf(&lpi, "lproc:%i:%s:%s:%s",
ctx->lproc.pid,
STRORDASH(ctx->lproc.user),
STRORDASH(ctx->lproc.group),
STRORDASH(ctx->lproc.exec_path));
if ((rv < 0) || !lpi) {
ctx->enomem = 1;
goto out;
}
} else {
lpi = "";
}
#endif /* HAVE_LOCAL_PROCINFO */
/*
* The following ifdef's within asprintf arguments list generates
* warnings with -Wembedded-directive on some compilers.
* Not fixing the code in order to avoid more code duplication.
*/
if (!ctx->src.ssl) {
rv = asprintf(&msg, "CONN: %s %s %s %s %s"
#ifdef HAVE_LOCAL_PROCINFO
" %s"
#endif /* HAVE_LOCAL_PROCINFO */
"\n",
ctx->proto == PROTO_PASSTHROUGH ? "passthrough" : (ctx->proto == PROTO_POP3 ? "pop3" : (ctx->proto == PROTO_SMTP ? "smtp" : "tcp")),
STRORDASH(ctx->srchost_str),
STRORDASH(ctx->srcport_str),
STRORDASH(ctx->dsthost_str),
STRORDASH(ctx->dstport_str)
#ifdef HAVE_LOCAL_PROCINFO
, lpi
#endif /* HAVE_LOCAL_PROCINFO */
);
} else {
rv = asprintf(&msg, "CONN: %s %s %s %s %s "
"sni:%s names:%s "
"sproto:%s:%s dproto:%s:%s "
"origcrt:%s usedcrt:%s"
#ifdef HAVE_LOCAL_PROCINFO
" %s"
#endif /* HAVE_LOCAL_PROCINFO */
"\n",
ctx->proto == PROTO_AUTOSSL ? "autossl" : (ctx->proto == PROTO_POP3S ? "pop3s" : (ctx->proto == PROTO_SMTPS ? "smtps" : "ssl")),
STRORDASH(ctx->srchost_str),
STRORDASH(ctx->srcport_str),
STRORDASH(ctx->dsthost_str),
STRORDASH(ctx->dstport_str),
STRORDASH(ctx->sslctx->sni),
STRORDASH(ctx->sslctx->ssl_names),
SSL_get_version(ctx->src.ssl),
SSL_get_cipher(ctx->src.ssl),
!ctx->srv_dst.closed && ctx->srv_dst.ssl ? SSL_get_version(ctx->srv_dst.ssl):ctx->sslctx->srv_dst_ssl_version,
!ctx->srv_dst.closed && ctx->srv_dst.ssl ? SSL_get_cipher(ctx->srv_dst.ssl):ctx->sslctx->srv_dst_ssl_cipher,
STRORDASH(ctx->sslctx->origcrtfpr),
STRORDASH(ctx->sslctx->usedcrtfpr)
#ifdef HAVE_LOCAL_PROCINFO
, lpi
#endif /* HAVE_LOCAL_PROCINFO */
);
}
if ((rv < 0) || !msg) {
ctx->enomem = 1;
goto out;
}
if (!ctx->opts->detach) {
log_err_printf("%s", msg);
} else if (ctx->opts->statslog) {
if (log_conn(msg) == -1) {
log_err_level_printf(LOG_WARNING, "Conn logging failed\n");
}
}
if (ctx->opts->connectlog) {
if (log_connect_print_free(msg) == -1) {
free(msg);
log_err_level_printf(LOG_WARNING, "Connection logging failed\n");
}
} else {
free(msg);
}
out:
#ifdef HAVE_LOCAL_PROCINFO
if (lpi && ctx->opts->lprocinfo) {
free(lpi);
}
#endif /* HAVE_LOCAL_PROCINFO */
return;
}
int
pxy_log_content_buf(pxy_conn_ctx_t *ctx, unsigned char *buf, size_t sz, int req)
{
if (WANT_CONTENT_LOG(ctx->conn)) {
if (buf) {
logbuf_t *lb = logbuf_new_alloc(sz, NULL, NULL);
if (!lb) {
ctx->conn->enomem = 1;
return -1;
}
memcpy(lb->buf, buf, lb->sz);
if (log_content_submit(ctx->conn->logctx, lb, req) == -1) {
logbuf_free(lb);
log_err_level_printf(LOG_WARNING, "Content log submission failed\n");
return -1;
}
}
}
return 0;
}
int
pxy_log_content_inbuf(pxy_conn_ctx_t *ctx, struct evbuffer *inbuf, int req)
{
if (WANT_CONTENT_LOG(ctx->conn)) {
size_t sz = evbuffer_get_length(inbuf);
unsigned char *buf = malloc(sz);
if (!buf) {
ctx->conn->enomem = 1;
return -1;
}
if (evbuffer_copyout(inbuf, buf, sz) == -1) {
free(buf);
return -1;
}
if (pxy_log_content_buf(ctx, buf, sz, req) == -1) {
free(buf);
return -1;
}
}
return 0;
}
int
pxy_prepare_logging_local_procinfo(UNUSED pxy_conn_ctx_t *ctx)
{
#ifdef HAVE_LOCAL_PROCINFO
if (ctx->opts->lprocinfo) {
/* fetch process info */
if (proc_pid_for_addr(&ctx->lproc.pid,
(struct sockaddr*)&ctx->lproc.srcaddr,
ctx->lproc.srcaddrlen) == 0 &&
ctx->lproc.pid != -1 &&
proc_get_info(ctx->lproc.pid,
&ctx->lproc.exec_path,
&ctx->lproc.uid,
&ctx->lproc.gid) == 0) {
/* fetch user/group names */
ctx->lproc.user = sys_user_str(
ctx->lproc.uid);
ctx->lproc.group = sys_group_str(
ctx->lproc.gid);
if (!ctx->lproc.user ||
!ctx->lproc.group) {
ctx->enomem = 1;
pxy_conn_free(ctx, 1);
return -1;
}
}
}
#endif /* HAVE_LOCAL_PROCINFO */
return 0;
}
int
pxy_prepare_logging(pxy_conn_ctx_t *ctx)
{
/* prepare logging, part 2 */
if (WANT_CONNECT_LOG(ctx) || WANT_CONTENT_LOG(ctx)) {
return pxy_prepare_logging_local_procinfo(ctx);
}
if (WANT_CONTENT_LOG(ctx)) {
if (log_content_open(&ctx->logctx, ctx->opts,
STRORDASH(ctx->srchost_str), STRORDASH(ctx->srcport_str),
STRORDASH(ctx->dsthost_str), STRORDASH(ctx->dstport_str),
#ifdef HAVE_LOCAL_PROCINFO
ctx->lproc.exec_path,
ctx->lproc.user,
ctx->lproc.group
#else /* HAVE_LOCAL_PROCINFO */
NULL, NULL, NULL
#endif /* HAVE_LOCAL_PROCINFO */
) == -1) {
if (errno == ENOMEM)
ctx->enomem = 1;
pxy_conn_free(ctx, 1);
return -1;
}
}
return 0;
}
static void NONNULL(1,2)
pxy_log_dbg_connect_type(pxy_conn_ctx_t *ctx, pxy_conn_desc_t *this)
{
if (OPTS_DEBUG(ctx->opts)) {
if (this->ssl) {
char *keystr;
/* for SSL, we get two connect events */
log_dbg_printf("%s connected to [%s]:%s %s %s\n",
protocol_names[ctx->proto],
STRORDASH(ctx->dsthost_str), STRORDASH(ctx->dstport_str),
SSL_get_version(this->ssl), SSL_get_cipher(this->ssl));
keystr = ssl_ssl_masterkey_to_str(this->ssl);
if (keystr) {
log_dbg_print_free(keystr);
}
} else {
/* for TCP, we get only a dst connect event,
* since src was already connected from the
* beginning; mirror SSL debug output anyway
* in order not to confuse anyone who might be
* looking closely at the output */
log_dbg_printf("%s connected to [%s]:%s\n",
protocol_names[ctx->proto],
STRORDASH(ctx->dsthost_str), STRORDASH(ctx->dstport_str));
log_dbg_printf("%s connected from [%s]:%s\n",
protocol_names[ctx->proto],
STRORDASH(ctx->srchost_str), STRORDASH(ctx->srcport_str));
}
}
}
void
pxy_log_connect_src(pxy_conn_ctx_t *ctx)
{
/* log connection if we don't analyze any headers */
if (!ctx->spec->http && (WANT_CONNECT_LOG(ctx) || ctx->opts->statslog)) {
pxy_log_connect_nonhttp(ctx);
}
if (ctx->src.ssl && ctx->opts->certgendir) {
/* write SSL certificates to gendir */
protossl_srccert_write(ctx);
}
if (protossl_log_masterkey(ctx, &ctx->src) == -1) {
return;
}
pxy_log_dbg_connect_type(ctx, &ctx->src);
}
void
pxy_log_connect_srv_dst(pxy_conn_ctx_t *ctx)
{
// @attention srv_dst.bev may be NULL, if its writecb fires first
if (ctx->srv_dst.bev) {
/* log connection if we don't analyze any headers */
if (!ctx->srv_dst.ssl && !ctx->spec->http && (WANT_CONNECT_LOG(ctx) || ctx->opts->statslog)) {
pxy_log_connect_nonhttp(ctx);
}
if (protossl_log_masterkey(ctx, &ctx->srv_dst) == -1) {
return;
}
pxy_log_dbg_connect_type(ctx, &ctx->srv_dst);
}
}
void
pxy_log_dbg_evbuf_info(UNUSED pxy_conn_ctx_t *ctx, UNUSED pxy_conn_desc_t *this, UNUSED pxy_conn_desc_t *other)
{
#ifdef DEBUG_PROXY
// Use ctx->conn, because this function is used by child conns too
if (OPTS_DEBUG(ctx->conn->opts)) {
log_dbg_printf("evbuffer size at EOF: i:%zu o:%zu i:%zu o:%zu\n",
evbuffer_get_length(bufferevent_get_input(this->bev)),
evbuffer_get_length(bufferevent_get_output(this->bev)),
other->closed ? 0 : evbuffer_get_length(bufferevent_get_input(other->bev)),
other->closed ? 0 : evbuffer_get_length(bufferevent_get_output(other->bev)));
}
#endif /* DEBUG_PROXY */
}
static void
pxy_log_dbg_disconnect(pxy_conn_ctx_t *ctx)
{
/* we only get a single disconnect event here for both connections */
if (OPTS_DEBUG(ctx->opts)) {
log_dbg_printf("%s disconnected to [%s]:%s, fd=%d\n",
protocol_names[ctx->proto],
STRORDASH(ctx->dsthost_str), STRORDASH(ctx->dstport_str), ctx->fd);
log_dbg_printf("%s disconnected from [%s]:%s, fd=%d\n",
protocol_names[ctx->proto],
STRORDASH(ctx->srchost_str), STRORDASH(ctx->srcport_str), ctx->fd);
}
}
static void
pxy_log_dbg_disconnect_child(pxy_conn_child_ctx_t *ctx)
{
/* we only get a single disconnect event here for both connections */
if (OPTS_DEBUG(ctx->conn->opts)) {
log_dbg_printf("Child %s disconnected to [%s]:%s, child fd=%d, fd=%d\n",
protocol_names[ctx->proto],
STRORDASH(ctx->conn->dsthost_str), STRORDASH(ctx->conn->dstport_str), ctx->fd, ctx->conn->fd);
log_dbg_printf("Child %s disconnected from [%s]:%s, child fd=%d, fd=%d\n",
protocol_names[ctx->proto],
STRORDASH(ctx->conn->srchost_str), STRORDASH(ctx->conn->srcport_str), ctx->fd, ctx->conn->fd);
}
}
#ifdef HAVE_NETFILTER
/*
* Copied from:
* https://github.com/tmux/tmux/blob/master/compat/getdtablecount.c
*/
int
getdtablecount()
{
char path[PATH_MAX];
glob_t g;
int n = 0;
if (snprintf(path, sizeof path, "/proc/%ld/fd/*", (long)getpid()) < 0) {
log_err_level_printf(LOG_CRIT, "snprintf overflow\n");
return 0;
}
if (glob(path, 0, NULL, &g) == 0)
n = g.gl_pathc;
globfree(&g);
return n;
}
#endif /* HAVE_NETFILTER */
unsigned char *
pxy_malloc_packet(size_t sz, pxy_conn_ctx_t *ctx)
{
unsigned char *packet = malloc(sz);
if (!packet) {
// @todo Should we just set enomem?
ctx->enomem = 1;
pxy_conn_free(ctx, 1);
return NULL;
}
return packet;
}
#ifdef DEBUG_PROXY
char *bev_names[] = {
"src",
"dst",
"srv_dst",
"NULL",
"UNKWN"
};
static char *
pxy_get_event_name(struct bufferevent *bev, pxy_conn_ctx_t *ctx)
{
// XXX: Used by watermark functions only, remove
if (bev == ctx->src.bev) {
return bev_names[0];
} else if (bev == ctx->dst.bev) {
return bev_names[1];
} else if (bev == ctx->srv_dst.bev) {
return bev_names[2];
} else if (bev == NULL) {
log_dbg_level_printf(LOG_DBG_MODE_FINE, "pxy_get_event_name: event_name=NULL\n");
return bev_names[3];
} else {
log_dbg_level_printf(LOG_DBG_MODE_FINE, "pxy_get_event_name: event_name=UNKWN\n");
return bev_names[4];
}
}
#endif /* DEBUG_PROXY */
void
pxy_try_set_watermark(struct bufferevent *bev, pxy_conn_ctx_t *ctx, struct bufferevent *other)
{
if (evbuffer_get_length(bufferevent_get_output(other)) >= OUTBUF_LIMIT) {
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINE, "pxy_try_set_watermark: %s, fd=%d\n", pxy_get_event_name(bev, ctx), ctx->fd);
#endif /* DEBUG_PROXY */
/* temporarily disable data source;
* set an appropriate watermark. */
bufferevent_setwatermark(other, EV_WRITE, OUTBUF_LIMIT/2, OUTBUF_LIMIT);
bufferevent_disable(bev, EV_READ);
ctx->thr->set_watermarks++;
}
}
void
pxy_try_unset_watermark(struct bufferevent *bev, pxy_conn_ctx_t *ctx, pxy_conn_desc_t *other)
{
if (other->bev && !(bufferevent_get_enabled(other->bev) & EV_READ)) {
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINE, "pxy_try_unset_watermark: %s, fd=%d\n", pxy_get_event_name(bev, ctx), ctx->fd);
#endif /* DEBUG_PROXY */
/* data source temporarily disabled;
* re-enable and reset watermark to 0. */
bufferevent_setwatermark(bev, EV_WRITE, 0, 0);
bufferevent_enable(other->bev, EV_READ);
ctx->thr->unset_watermarks++;
}
}
void
pxy_discard_inbuf(struct bufferevent *bev)
{
struct evbuffer *inbuf = bufferevent_get_input(bev);
size_t inbuf_size = evbuffer_get_length(inbuf);
log_dbg_printf("Warning: Drained %zu bytes (conn closed)\n", inbuf_size);
evbuffer_drain(inbuf, inbuf_size);
}
void
pxy_insert_sslproxy_header(pxy_conn_ctx_t *ctx, unsigned char *packet, size_t *packet_size)
{
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINER, "pxy_insert_sslproxy_header: INSERT, fd=%d\n", ctx->fd);
#endif /* DEBUG_PROXY */
// @attention Cannot use string manipulation functions; we are dealing with binary arrays here, not NULL-terminated strings
memmove(packet + ctx->sslproxy_header_len + 2, packet, *packet_size);
memcpy(packet, ctx->sslproxy_header, ctx->sslproxy_header_len);
memcpy(packet + ctx->sslproxy_header_len, "\r\n", 2);
*packet_size+= ctx->sslproxy_header_len + 2;
ctx->sent_sslproxy_header = 1;
}
void
pxy_try_remove_sslproxy_header(pxy_conn_child_ctx_t *ctx, unsigned char *packet, size_t *packet_size)
{
// @attention Cannot use string manipulation functions; we are dealing with binary arrays here, not NULL-terminated strings
unsigned char *pos = memmem(packet, *packet_size, ctx->conn->sslproxy_header, ctx->conn->sslproxy_header_len);
if (pos) {
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINER, "pxy_try_remove_sslproxy_header: REMOVE, child fd=%d, fd=%d\n", ctx->fd, ctx->conn->fd);
#endif /* DEBUG_PROXY */
memmove(pos, pos + ctx->conn->sslproxy_header_len + 2, *packet_size - (pos - packet) - (ctx->conn->sslproxy_header_len + 2));
*packet_size-= ctx->conn->sslproxy_header_len + 2;
ctx->removed_sslproxy_header = 1;
}
}
/*
* Callback for accept events on the socket listener bufferevent.
*/
static void
pxy_listener_acceptcb_child(UNUSED struct evconnlistener *listener, evutil_socket_t fd,
UNUSED struct sockaddr *peeraddr, UNUSED int peeraddrlen, void *arg)
{
pxy_conn_ctx_t *conn = arg;
conn->atime = time(NULL);
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINEST, "pxy_listener_acceptcb_child: ENTER, child fd=%d, conn->child_fd=%d, fd=%d\n", fd, conn->child_fd, conn->fd);
char *host, *port;
if (sys_sockaddr_str(peeraddr, peeraddrlen, &host, &port) == 0) {
log_dbg_level_printf(LOG_DBG_MODE_FINEST, "pxy_listener_acceptcb_child: peer addr=[%s]:%s, child fd=%d, fd=%d\n", host, port, fd, conn->fd);
free(host);
free(port);
}
#endif /* DEBUG_PROXY */
if (!conn->addrlen) {
log_err_level_printf(LOG_CRIT, "Child no target address; aborting connection\n");
evutil_closesocket(fd);
pxy_conn_free(conn, 1);
return;
}
int dtable_count = getdtablecount();
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINER, "pxy_listener_acceptcb_child: descriptor_table_size=%d, current fd count=%d, reserve=%d, fd=%d\n",
descriptor_table_size, dtable_count, FD_RESERVE, fd);
#endif /* DEBUG_PROXY */
// Close the conn if we are out of file descriptors, or libevent will crash us, @see pxy_conn_setup() for explanation
if (dtable_count + FD_RESERVE >= descriptor_table_size) {
errno = EMFILE;
log_err_level_printf(LOG_CRIT, "Out of file descriptors\n");
evutil_closesocket(fd);
pxy_conn_free(conn, 1);
return;
}
pxy_conn_child_ctx_t *ctx = pxy_conn_ctx_new_child(fd, conn);
if (!ctx) {
log_err_level_printf(LOG_CRIT, "Error allocating memory\n");
evutil_closesocket(fd);
pxy_conn_free(conn, 1);
return;
}
// Prepend child ctx to conn ctx child list
// @attention If the last child is deleted, the children list may become null again
ctx->next = conn->children;
conn->children = ctx;
conn->child_count++;
ctx->idx = conn->child_count;
// @attention Do not enable src events here yet, they will be enabled after dst connects
if (prototcp_setup_src_child(ctx) == -1) {
return;
}
// src_fd is different from fd
ctx->src_fd = bufferevent_getfd(ctx->src.bev);
ctx->conn->child_src_fd = ctx->src_fd;
ctx->conn->thr->max_fd = MAX(ctx->conn->thr->max_fd, ctx->src_fd);
/* create server-side socket and eventbuffer */
// Children rely on the findings of parent
ctx->protoctx->connectcb(ctx);
bufferevent_enable(ctx->dst.bev, EV_READ|EV_WRITE);
if (OPTS_DEBUG(ctx->conn->opts)) {
char *host, *port;
if (sys_sockaddr_str((struct sockaddr *)&ctx->conn->addr, ctx->conn->addrlen, &host, &port) == 0) {
log_dbg_printf("Child connecting to [%s]:%s\n", host, port);
free(host);
free(port);
} else {
log_dbg_printf("Child connecting to [?]:?\n");
}
}
/* initiate connection */
// @attention No need to check retval here, the eventcb should handle the errors
bufferevent_socket_connect(ctx->dst.bev, (struct sockaddr *)&ctx->conn->addr, ctx->conn->addrlen);
ctx->dst_fd = bufferevent_getfd(ctx->dst.bev);
ctx->conn->child_dst_fd = ctx->dst_fd;
ctx->conn->thr->max_fd = MAX(ctx->conn->thr->max_fd, ctx->dst_fd);
}
int
pxy_setup_child_listener(pxy_conn_ctx_t *ctx)
{
// @attention Defer child setup and evcl creation until after parent init is complete, otherwise (1) causes multithreading issues (proxy_listener_acceptcb is
// running on a different thread from the conn, and we only have thrmgr mutex), and (2) we need to clean up less upon errors.
// Child evcls use the evbase of the parent thread, otherwise we would get multithreading issues.
if ((ctx->child_fd = privsep_client_opensock_child(ctx->clisock, ctx->spec)) == -1) {
log_err_level_printf(LOG_CRIT, "Error opening child socket: %s (%i)\n", strerror(errno), errno);
pxy_conn_free(ctx, 1);
return -1;
}
ctx->thr->max_fd = MAX(ctx->thr->max_fd, ctx->child_fd);
// @attention Do not pass NULL as user-supplied pointer
struct evconnlistener *child_evcl = evconnlistener_new(ctx->thr->evbase, pxy_listener_acceptcb_child, ctx, LEV_OPT_CLOSE_ON_FREE, 1024, ctx->child_fd);
if (!child_evcl) {
log_err_level_printf(LOG_CRIT, "Error creating child evconnlistener: %s\n", strerror(errno));
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINE, "pxy_setup_child_listener: Error creating child evconnlistener: %s, fd=%d, child_fd=%d\n", strerror(errno), ctx->fd, ctx->child_fd);
#endif /* DEBUG_PROXY */
// @attention Cannot call proxy_listener_ctx_free() on child_evcl, child_evcl does not have any ctx with next listener
// @attention Close child fd separately, because child evcl does not exist yet, hence fd would not be closed by calling pxy_conn_free()
evutil_closesocket(ctx->child_fd);
pxy_conn_free(ctx, 1);
return -1;
}
ctx->child_evcl = child_evcl;
evconnlistener_set_error_cb(child_evcl, proxy_listener_errorcb);
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINER, "pxy_setup_child_listener: Finished setting up child, NEW child_fd=%d, fd=%d\n", ctx->child_fd, ctx->fd);
#endif /* DEBUG_PROXY */
struct sockaddr_in child_listener_addr;
socklen_t child_listener_len = sizeof(child_listener_addr);
if (getsockname(ctx->child_fd, (struct sockaddr *)&child_listener_addr, &child_listener_len) < 0) {
log_err_level_printf(LOG_CRIT, "Error in getsockname: %s\n", strerror(errno));
// @todo If getsockname() fails, should we really terminate the connection?
// @attention Do not close the child fd here, because child evcl exists now, hence pxy_conn_free() will close it while freeing child_evcl
pxy_conn_free(ctx, 1);
return -1;
}
// @attention Children are always listening on an IPv4 loopback address
char addr[INET_ADDRSTRLEN];
if (!inet_ntop(AF_INET, &child_listener_addr.sin_addr, addr, INET_ADDRSTRLEN)) {
pxy_conn_free(ctx, 1);
return -1;
}
if (pxy_set_dstaddr(ctx) == -1) {
return -1;
}
// SSLproxy: [127.0.0.1]:34649,[192.168.3.24]:47286,[74.125.206.108]:465,s
// @todo Port may be less than 5 chars
// SSLproxy: + + [ + addr + ] + : + p + , + [ + srchost_str + ] + : + srcport_str + , + [ + dsthost_str + ] + : + dstport_str + , + s
// SSLPROXY_KEY_LEN + 1 + 1 + strlen(addr) + 1 + 1 + 5 + 1 + 1 + strlen(ctx->srchost_str) + 1 + 1 + strlen(ctx->srcport_str) + 1 + 1 + strlen(ctx->dsthost_str) + 1 + 1 + strlen(ctx->dstport_str) + 1 + 1
ctx->sslproxy_header_len = SSLPROXY_KEY_LEN + strlen(addr) + strlen(ctx->srchost_str) + strlen(ctx->srcport_str) + strlen(ctx->dsthost_str) + strlen(ctx->dstport_str) + 19;
// @todo Always check malloc retvals. Should we close the conn if malloc fails?
// +1 for NULL
ctx->sslproxy_header = malloc(ctx->sslproxy_header_len + 1);
if (!ctx->sslproxy_header) {
pxy_conn_free(ctx, 1);
return -1;
}
// printf(3): "snprintf() will write at most size-1 of the characters (the size'th character then gets the terminating NULL)"
// So, +1 for NULL
snprintf(ctx->sslproxy_header, ctx->sslproxy_header_len + 1, "%s [%s]:%u,[%s]:%s,[%s]:%s,%s",
SSLPROXY_KEY, addr, ntohs(child_listener_addr.sin_port), STRORNONE(ctx->srchost_str), STRORNONE(ctx->srcport_str),
STRORNONE(ctx->dsthost_str), STRORNONE(ctx->dstport_str), ctx->spec->ssl ? "s":"p");
return 0;
}
int
pxy_try_close_conn_end(pxy_conn_desc_t *conn_end, pxy_conn_ctx_t *ctx, bufferevent_free_and_close_fd_func_t free_and_close_fd_func)
{
/* if the other end is still open and doesn't have data
* to send, close it, otherwise its writecb will close
* it after writing what's left in the output buffer */
if (evbuffer_get_length(bufferevent_get_output(conn_end->bev)) == 0) {
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINEST, "pxy_try_close_conn_end: evbuffer_get_length(outbuf) == 0, terminate conn, fd=%d\n", ctx->fd);
#endif /* DEBUG_PROXY */
free_and_close_fd_func(conn_end->bev, ctx);
conn_end->bev = NULL;
conn_end->closed = 1;
return 1;
}
return 0;
}
void
pxy_try_connect_srv_dst(struct bufferevent *bev, pxy_conn_ctx_t *ctx)
{
if (!ctx->srv_dst_connected) {
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINE, "pxy_try_connect_srv_dst: writecb before connected, fd=%d\n", ctx->fd);
#endif /* DEBUG_PROXY */
// @attention Sometimes dst write cb fires but not event cb, especially if the listener cb is not finished yet, so the conn stalls.
// This is a workaround for this error condition, nothing else seems to work.
// @attention Do not try to free the conn here, since the listener cb may not be finished yet, which causes multithreading issues
// XXX: Workaround, should find the real cause: BEV_OPT_DEFER_CALLBACKS?
ctx->protoctx->bev_eventcb(bev, BEV_EVENT_CONNECTED, ctx);
}
}
void
pxy_try_disconnect(pxy_conn_ctx_t *ctx, pxy_conn_desc_t *this,
bufferevent_free_and_close_fd_func_t this_free_and_close_fd_func, pxy_conn_desc_t *other, int is_requestor)
{
// @attention srv_dst should never reach here unless in passthrough mode, its bev may be NULL
this->closed = 1;
this_free_and_close_fd_func(this->bev, ctx);
this->bev = NULL;
if (other->closed) {
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINEST, "pxy_try_disconnect: other->closed, terminate conn, fd=%d\n", ctx->fd);
#endif /* DEBUG_PROXY */
// Uses only ctx to log disconnect, never any of the bevs
pxy_log_dbg_disconnect(ctx);
pxy_conn_free(ctx, is_requestor);
}
}
void
pxy_try_disconnect_child(pxy_conn_child_ctx_t *ctx, pxy_conn_desc_t *this,
bufferevent_free_and_close_fd_func_t this_free_and_close_fd_func, pxy_conn_desc_t *other)
{
this->closed = 1;
this_free_and_close_fd_func(this->bev, ctx->conn);
this->bev = NULL;
if (other->closed) {
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINEST, "pxy_try_disconnect_child: other->closed, terminate conn, child fd=%d, fd=%d\n", ctx->fd, ctx->conn->fd);
#endif /* DEBUG_PROXY */
// Uses only ctx to log disconnect, never any of the bevs
pxy_log_dbg_disconnect_child(ctx);
pxy_conn_free_child(ctx);
}
}
void
pxy_try_consume_last_input(struct bufferevent *bev, pxy_conn_ctx_t *ctx)
{
/* if there is data pending in the closed connection,
* handle it here, otherwise it will be lost. */
if (evbuffer_get_length(bufferevent_get_input(bev))) {
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINE, "pxy_try_consume_last_input: evbuffer_get_length(inbuf) > 0, terminate conn, fd=%d\n", ctx->fd);
#endif /* DEBUG_PROXY */
ctx->protoctx->bev_readcb(bev, ctx);
}
}
void
pxy_try_consume_last_input_child(struct bufferevent *bev, pxy_conn_child_ctx_t *ctx)
{
/* if there is data pending in the closed connection,
* handle it here, otherwise it will be lost. */
if (evbuffer_get_length(bufferevent_get_input(bev))) {
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINE, "pxy_try_consume_last_input_child: evbuffer_get_length(inbuf) > 0, terminate conn, child fd=%d, fd=%d\n", ctx->fd, ctx->conn->fd);
#endif /* DEBUG_PROXY */
ctx->protoctx->bev_readcb(bev, ctx);
}
}
int
pxy_set_dstaddr(pxy_conn_ctx_t *ctx)
{
if (sys_sockaddr_str((struct sockaddr *)&ctx->addr, ctx->addrlen, &ctx->dsthost_str, &ctx->dstport_str) != 0) {
ctx->enomem = 1;
pxy_conn_free(ctx, 1);
return -1;
}
return 0;
}
/*
* Callback for read events on the up- and downstream connection bufferevents.
* Called when there is data ready in the input evbuffer.
*/
void
pxy_bev_readcb(struct bufferevent *bev, void *arg)
{
pxy_conn_ctx_t *ctx = arg;
if (bev == ctx->src.bev || bev == ctx->dst.bev) {
struct evbuffer *inbuf = bufferevent_get_input(bev);
size_t inbuf_size = evbuffer_get_length(inbuf);
if (bev == ctx->src.bev) {
ctx->thr->intif_in_bytes += inbuf_size;
} else {
ctx->thr->intif_out_bytes += inbuf_size;
}
if (ctx->proto != PROTO_PASSTHROUGH) {
// HTTP content logging at this point may record certain headers twice, if we have not seen all header lines yet
if (pxy_log_content_inbuf(ctx, inbuf, (bev == ctx->src.bev)) == -1) {
return;
}
}
}
if (!ctx->connected) {
log_err_level_printf(LOG_CRIT, "pxy_bev_readcb: readcb called when not connected - aborting.\n");
log_exceptcb();
return;
}
ctx->atime = time(NULL);
ctx->protoctx->bev_readcb(bev, ctx);
}
void
pxy_bev_readcb_child(struct bufferevent *bev, void *arg)
{
pxy_conn_child_ctx_t *ctx = arg;
struct evbuffer *inbuf = bufferevent_get_input(bev);
size_t inbuf_size = evbuffer_get_length(inbuf);
if (bev == ctx->src.bev) {
ctx->conn->thr->extif_out_bytes += inbuf_size;
} else {
ctx->conn->thr->extif_in_bytes += inbuf_size;
}
if (ctx->proto != PROTO_PASSTHROUGH) {
if (pxy_log_content_inbuf((pxy_conn_ctx_t *)ctx, inbuf, (bev == ctx->src.bev)) == -1) {
return;
}
}
if (!ctx->connected) {
log_err_level_printf(LOG_CRIT, "pxy_bev_readcb_child: readcb called when not connected - aborting.\n");
log_exceptcb();
return;
}
ctx->conn->atime = time(NULL);
ctx->protoctx->bev_readcb(bev, ctx);
}
/*
* Callback for write events on the up- and downstream connection bufferevents.
* Called when either all data from the output evbuffer has been written,
* or if the outbuf is only half full again after having been full.
*/
void
pxy_bev_writecb(struct bufferevent *bev, void *arg)
{
pxy_conn_ctx_t *ctx = arg;
ctx->atime = time(NULL);
ctx->protoctx->bev_writecb(bev, ctx);
}
void
pxy_bev_writecb_child(struct bufferevent *bev, void *arg)
{
pxy_conn_child_ctx_t *ctx = arg;
ctx->conn->atime = time(NULL);
ctx->protoctx->bev_writecb(bev, ctx);
}
/*
* Callback for meta events on the up- and downstream connection bufferevents.
* Called when EOF has been reached, a connection has been made, and on errors.
*/
void
pxy_bev_eventcb(struct bufferevent *bev, short events, void *arg)
{
pxy_conn_ctx_t *ctx = arg;
ctx->atime = time(NULL);
if (events & BEV_EVENT_ERROR) {
log_err_printf("Client-side BEV_EVENT_ERROR\n");
ctx->thr->errors++;
}
ctx->protoctx->bev_eventcb(bev, events, arg);
if (events & BEV_EVENT_CONNECTED) {
// Passthrough proto does its own connect logging
if (ctx->proto != PROTO_PASSTHROUGH) {
if (bev == ctx->src.bev) {
// @todo When do we reach here? If proto is autossl? Otherwise, src is connected in acceptcb.
pxy_log_connect_src(ctx);
} else if (ctx->connected) {
if (pxy_prepare_logging(ctx) == -1) {
return;
}
// Doesn't log connect if proto is http, http proto does its own connect logging
pxy_log_connect_srv_dst(ctx);
}
}
if (bev == ctx->srv_dst.bev) {
// src and other fd stats are collected in acceptcb functions
ctx->srv_dst_fd = bufferevent_getfd(ctx->srv_dst.bev);
ctx->thr->max_fd = MAX(ctx->thr->max_fd, ctx->srv_dst_fd);
// Passthrough proto may have a NULL dst.bev
if (ctx->dst.bev) {
ctx->dst_fd = bufferevent_getfd(ctx->dst.bev);
ctx->thr->max_fd = MAX(ctx->thr->max_fd, ctx->dst_fd);
}
}
}
}
void
pxy_bev_eventcb_child(struct bufferevent *bev, short events, void *arg)
{
pxy_conn_child_ctx_t *ctx = arg;
ctx->conn->atime = time(NULL);
if (events & BEV_EVENT_ERROR) {
log_err_printf("Server-side BEV_EVENT_ERROR\n");
ctx->conn->thr->errors++;
}
ctx->protoctx->bev_eventcb(bev, events, arg);
if (events & BEV_EVENT_CONNECTED) {
ctx->conn->thr->max_fd = MAX(ctx->conn->thr->max_fd, MAX(bufferevent_getfd(ctx->src.bev), bufferevent_getfd(ctx->dst.bev)));
}
}
/*
* Complete the connection. This gets called after finding out where to
* connect to.
*/
void
pxy_conn_connect(pxy_conn_ctx_t *ctx)
{
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINEST, "pxy_conn_connect: ENTER, fd=%d\n", ctx->fd);
#endif /* DEBUG_PROXY */
if (!ctx->addrlen) {
log_err_level_printf(LOG_CRIT, "No target address; aborting connection\n");
evutil_closesocket(ctx->fd);
pxy_conn_ctx_free(ctx, 1);
return;
}
if (OPTS_DEBUG(ctx->opts)) {
char *host, *port;
if (sys_sockaddr_str((struct sockaddr *)&ctx->addr, ctx->addrlen, &host, &port) == 0) {
log_dbg_printf("Connecting to [%s]:%s\n", host, port);
free(host);
free(port);
} else {
log_dbg_printf("Connecting to [?]:?\n");
}
}
ctx->protoctx->connectcb(ctx);
// @attention Do not do anything else with the ctx after connecting socket, otherwise if pxy_bev_eventcb fires on error, such as due to "No route to host",
// the conn is closed and freed up, and we get multithreading issues, e.g. signal 11. We are on the thrmgr thread. So, just return.
}
/*
* The src fd is readable. This is used to sneak-preview the SNI on SSL
* connections. If ctx->ev is NULL, it was called manually for a non-SSL
* connection. If ctx->passthrough is set, it was called a second time
* after the first ssl callout failed because of client cert auth.
*/
void
pxy_fd_readcb(evutil_socket_t fd, UNUSED short what, void *arg)
{
pxy_conn_ctx_t *ctx = arg;
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINEST, "pxy_fd_readcb: ENTER, fd=%d\n", ctx->fd);
#endif /* DEBUG_PROXY */
ctx->atime = time(NULL);
ctx->protoctx->fd_readcb(fd, what, arg);
}
/*
* Callback for accept events on the socket listener bufferevent.
* Called when a new incoming connection has been accepted.
* Initiates the connection to the server. The incoming connection
* from the client is not being activated until we have a successful
* connection to the server, because we need the server's certificate
* in order to set up the SSL session to the client.
* For consistency, plain TCP works the same way, even if we could
* start reading from the client while waiting on the connection to
* the server to connect.
*/
void
pxy_conn_setup(evutil_socket_t fd,
struct sockaddr *peeraddr, int peeraddrlen,
pxy_thrmgr_ctx_t *thrmgr,
proxyspec_t *spec, opts_t *opts,
evutil_socket_t clisock)
{
int dtable_count = getdtablecount();
#ifdef DEBUG_PROXY
log_dbg_level_printf(LOG_DBG_MODE_FINEST, "pxy_conn_setup: ENTER, fd=%d\n", fd);
char *host, *port;
if (sys_sockaddr_str(peeraddr, peeraddrlen, &host, &port) == 0) {
log_dbg_level_printf(LOG_DBG_MODE_FINEST, "pxy_conn_setup: peer addr=[%s]:%s, fd=%d\n", host, port, fd);
free(host);
free(port);
}
log_dbg_level_printf(LOG_DBG_MODE_FINER, "pxy_conn_setup: descriptor_table_size=%d, current fd count=%d, reserve=%d\n",
descriptor_table_size, dtable_count, FD_RESERVE);
#endif /* DEBUG_PROXY */
// Close the conn if we are out of file descriptors, or libevent will crash us
// @attention We cannot guess the number of children in a connection at conn setup time. So, FD_RESERVE is just a ball park figure.
// But what if a connection passes the check below, but eventually tries to create more children than FD_RESERVE allows for? This will crash us the same.
// Beware, this applies to all current conns, not just the last connection setup.
// For example, 20x conns pass the check below before creating any children, at which point we reach at the last FD_RESERVE fds,
// then they all start creating children, which crashes us again.
// So, no matter how large an FD_RESERVE we choose, there will always be a risk of running out of fds, if we check the number of fds here only.
// If we are left with less than FD_RESERVE fds, we should not create more children than FD_RESERVE allows for either.
// Therefore, we check if we are out of fds in proxy_listener_acceptcb_child() and close the conn there too.
// @attention These checks are expected to slow us further down, but it is critical to avoid a crash in case we run out of fds.
if (dtable_count + FD_RESERVE >= descriptor_table_size) {
errno = EMFILE;
log_err_level_printf(LOG_CRIT, "Out of file descriptors\n");
evutil_closesocket(fd);
return;
}
/* create per connection state and attach to thread */
pxy_conn_ctx_t *ctx = pxy_conn_ctx_new(fd, thrmgr, spec, opts, clisock);
if (!ctx) {
log_err_level_printf(LOG_CRIT, "Error allocating memory\n");
evutil_closesocket(fd);
return;
}
ctx->af = peeraddr->sa_family;
ctx->thr->max_fd = MAX(ctx->thr->max_fd, ctx->fd);
/* determine original destination of connection */
if (spec->natlookup) {
/* NAT engine lookup */
ctx->addrlen = sizeof(struct sockaddr_storage);
if (spec->natlookup((struct sockaddr *)&ctx->addr, &ctx->addrlen, fd, peeraddr, peeraddrlen) == -1) {
log_err_printf("Connection not found in NAT state table, aborting connection\n");
evutil_closesocket(fd);
pxy_conn_ctx_free(ctx, 1);
return;
}
} else if (spec->connect_addrlen > 0) {
/* static forwarding */
ctx->addrlen = spec->connect_addrlen;
memcpy(&ctx->addr, &spec->connect_addr, ctx->addrlen);
} else {
/* SNI mode */
if (!ctx->spec->ssl) {
/* if this happens, the proxyspec parser is broken */
log_err_printf("SNI mode used for non-SSL connection; aborting connection\n");
evutil_closesocket(fd);
pxy_conn_ctx_free(ctx, 1);
return;
}
}
if (sys_sockaddr_str(peeraddr, peeraddrlen, &ctx->srchost_str, &ctx->srcport_str) != 0) {
goto memout;
}
/* prepare logging, part 1 */
if (WANT_CONNECT_LOG(ctx) || WANT_CONTENT_LOG(ctx)) {
#ifdef HAVE_LOCAL_PROCINFO
if (ctx->opts->lprocinfo) {
memcpy(&ctx->lproc.srcaddr, peeraddr, peeraddrlen);
ctx->lproc.srcaddrlen = peeraddrlen;
}
#endif /* HAVE_LOCAL_PROCINFO */
}
/* for SSL, defer dst connection setup to initial_readcb */
if (ctx->spec->ssl) {
ctx->ev = event_new(ctx->evbase, fd, EV_READ, ctx->protoctx->fd_readcb, ctx);
if (!ctx->ev)
goto memout;
event_add(ctx->ev, NULL);
} else {
ctx->protoctx->fd_readcb(fd, 0, ctx);
}
return;
memout:
log_err_level_printf(LOG_CRIT, "Aborting connection setup (out of memory)!\n");
evutil_closesocket(fd);
pxy_conn_ctx_free(ctx, 1);
}
/* vim: set noet ft=c: */
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