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Diffstat (limited to 'nsock/src/proxy_http.c')
-rw-r--r-- | nsock/src/proxy_http.c | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/nsock/src/proxy_http.c b/nsock/src/proxy_http.c new file mode 100644 index 0000000..a6831d4 --- /dev/null +++ b/nsock/src/proxy_http.c @@ -0,0 +1,210 @@ +/*************************************************************************** + * proxy_http.c -- HTTP Connect proxying. * + * * + ***********************IMPORTANT NSOCK LICENSE TERMS*********************** + * + * The nsock parallel socket event library is (C) 1999-2023 Nmap Software LLC + * This library is free software; you may redistribute and/or modify it under + * the terms of the GNU General Public License as published by the Free Software + * Foundation; Version 2. This guarantees your right to use, modify, and + * redistribute this software under certain conditions. If this license is + * unacceptable to you, Nmap Software LLC may be willing to sell alternative + * licenses (contact sales@nmap.com ). + * + * As a special exception to the GPL terms, Nmap Software LLC grants permission + * to link the code of this program with any version of the OpenSSL library + * which is distributed under a license identical to that listed in the included + * docs/licenses/OpenSSL.txt file, and distribute linked combinations including + * the two. You must obey the GNU GPL in all respects for all of the code used + * other than OpenSSL. If you modify this file, you may extend this exception to + * your version of the file, but you are not obligated to do so. + * + * If you received these files with a written license agreement stating terms + * other than the (GPL) terms above, then that alternative license agreement + * takes precedence over this comment. + * + * Source is provided to this software because we believe users have a right to + * know exactly what a program is going to do before they run it. This also + * allows you to audit the software for security holes. + * + * Source code also allows you to port Nmap to new platforms, fix bugs, and add + * new features. You are highly encouraged to send your changes to the + * dev@nmap.org mailing list for possible incorporation into the main + * distribution. By sending these changes to Fyodor or one of the Insecure.Org + * development mailing lists, or checking them into the Nmap source code + * repository, it is understood (unless you specify otherwise) that you are + * offering the Nmap Project (Nmap Software LLC) the unlimited, non-exclusive + * right to reuse, modify, and relicense the code. Nmap will always be available + * Open Source, but this is important because the inability to relicense code + * has caused devastating problems for other Free Software projects (such as KDE + * and NASM). We also occasionally relicense the code to third parties as + * discussed above. If you wish to specify special license conditions of your + * contributions, just say so when you send them. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS + * FOR A PARTICULAR PURPOSE. See the GNU General Public License v2.0 for more + * details (http://www.gnu.org/licenses/gpl-2.0.html). + * + ***************************************************************************/ + +/* $Id $ */ + +#define _GNU_SOURCE +#include <stdio.h> + +#include "nsock.h" +#include "nsock_internal.h" +#include "nsock_log.h" +#include <string.h> + +#define DEFAULT_PROXY_PORT_HTTP 8080 + + +extern struct timeval nsock_tod; +extern const struct proxy_spec ProxySpecHttp; + + +static int proxy_http_node_new(struct proxy_node **node, const struct uri *uri) { + int rc; + struct proxy_node *proxy; + + proxy = (struct proxy_node *)safe_zalloc(sizeof(struct proxy_node)); + proxy->spec = &ProxySpecHttp; + + rc = proxy_resolve(uri->host, (struct sockaddr *)&proxy->ss, &proxy->sslen, AF_UNSPEC); + if (rc < 0) { + free(proxy); + *node = NULL; + return -1; + } + + if (uri->port == -1) + proxy->port = DEFAULT_PROXY_PORT_HTTP; + else + proxy->port = (unsigned short)uri->port; + + rc = asprintf(&proxy->nodestr, "http://%s:%d", uri->host, proxy->port); + if (rc < 0) { + /* asprintf() failed for some reason but this is not a disaster (yet). + * Set nodestr to NULL and try to keep on going. */ + proxy->nodestr = NULL; + } + + *node = proxy; + + return 1; +} + +static void proxy_http_node_delete(struct proxy_node *node) { + if (!node) + return; + + free(node->nodestr); + + free(node); +} + +static int handle_state_initial(struct npool *nsp, struct nevent *nse, void *udata) { + struct proxy_chain_context *px_ctx = nse->iod->px_ctx; + struct sockaddr_storage *ss; + size_t sslen; + unsigned short port; + struct proxy_node *next; + int timeout; + + px_ctx->px_state = PROXY_STATE_HTTP_TCP_CONNECTED; + + next = proxy_ctx_node_next(px_ctx); + if (next) { + ss = &next->ss; + sslen = next->sslen; + port = next->port; + } else { + ss = &px_ctx->target_ss; + sslen = px_ctx->target_sslen; + port = px_ctx->target_port; + } + + timeout = TIMEVAL_MSEC_SUBTRACT(nse->timeout, nsock_tod); + + nsock_printf(nsp, (nsock_iod)nse->iod, nsock_proxy_ev_dispatch, + timeout, udata, "CONNECT %s:%d HTTP/1.1\r\n\r\n", + inet_ntop_ez(ss, sslen), (int)port); + + nsock_readlines(nsp, (nsock_iod)nse->iod, nsock_proxy_ev_dispatch, + timeout, udata, 1); + + return 0; +} + +static int handle_state_tcp_connected(struct npool *nsp, struct nevent *nse, void *udata) { + struct proxy_chain_context *px_ctx = nse->iod->px_ctx; + char *res; + int reslen; + + res = nse_readbuf(nse, &reslen); + + /* TODO string check!! */ + if (!((reslen >= 15) && strstr(res, "200 OK"))) { + struct proxy_node *node = px_ctx->px_current; + + nsock_log_debug("Connection refused from proxy %s", node->nodestr); + return -EINVAL; + } + + px_ctx->px_state = PROXY_STATE_HTTP_TUNNEL_ESTABLISHED; + + if (proxy_ctx_node_next(px_ctx) == NULL) { + forward_event(nsp, nse, udata); + } else { + px_ctx->px_current = proxy_ctx_node_next(px_ctx); + px_ctx->px_state = PROXY_STATE_INITIAL; + nsock_proxy_ev_dispatch(nsp, nse, udata); + } + return 0; +} + +static void proxy_http_handler(nsock_pool nspool, nsock_event nsevent, void *udata) { + int rc = 0; + struct npool *nsp = (struct npool *)nspool; + struct nevent *nse = (struct nevent *)nsevent; + + switch (nse->iod->px_ctx->px_state) { + case PROXY_STATE_INITIAL: + rc = handle_state_initial(nsp, nse, udata); + break; + + case PROXY_STATE_HTTP_TCP_CONNECTED: + if (nse->type == NSE_TYPE_READ) + rc = handle_state_tcp_connected(nsp, nse, udata); + break; + + case PROXY_STATE_HTTP_TUNNEL_ESTABLISHED: + forward_event(nsp, nse, udata); + break; + + default: + fatal("Invalid proxy state!"); + } + + if (rc) { + nse->status = NSE_STATUS_PROXYERROR; + forward_event(nsp, nse, udata); + } +} + + +/* ---- PROXY DEFINITION ---- */ +static const struct proxy_op ProxyOpsHttp = { + proxy_http_node_new, + proxy_http_node_delete, + proxy_http_handler, +}; + +const struct proxy_spec ProxySpecHttp = { + "http://", + PROXY_TYPE_HTTP, + &ProxyOpsHttp, +}; + |