freebsd-skq/lib/libfetch/common.h
Kyle Evans c44be5aa0a fetch(3): Add SOCKS5 support
This change adds SOCKS5 support to the library fetch(3) and updates the man
page.

Details: Within the fetch_connect() function, fetch(3) checks if the
SOCKS5_PROXY environment variable is set. If so, it connects to this host
rather than the end-host. It then initializes the SOCKS5 connection in
accordance with RFC 1928 and returns the resulting conn_t (file descriptor)
for usage by the regular FTP/HTTP handlers.

Design Decision: This change defaults all DNS resolutions through the proxy
by sending all IPs as hostnames. Going forward, another feature might be to
create another environmental variable to toggle resolutions through the
proxy or not..

One may set the SOCKS5_PROXY environment variable in any of the formats:

SOCKS5_PROXY=proxy.example.com
SOCKS5_PROXY=proxy.example.com:1080
SOCKS5_PROXY=192.0.2.0
SOCKS5_PROXY=198.51.100.0:1080
SOCKS5_PROXY=[2001:db8::1]
SOCKS5_PROXY=[2001:db8::2]:1080

Then perform a request with fetch(1).

(note by kevans)
I've since been informed that Void Linux/xbps has a fork of libfetch that
also implements SOCKS5. I may compare/contrast the two in the mid-to-near
future.

Submitted by:	Farhan Khan <farhan farhan codes>
Differential Revision:	https://reviews.freebsd.org/D18908
2020-02-15 18:03:16 +00:00

178 lines
5.8 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1998-2014 Dag-Erling Smørgrav
* 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
* in this position and unchanged.
* 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*
* $FreeBSD$
*/
#ifndef _COMMON_H_INCLUDED
#define _COMMON_H_INCLUDED
#define FTP_DEFAULT_PORT 21
#define HTTP_DEFAULT_PORT 80
#define FTP_DEFAULT_PROXY_PORT 21
#define HTTP_DEFAULT_PROXY_PORT 3128
#ifdef WITH_SSL
#include <openssl/crypto.h>
#include <openssl/x509.h>
#include <openssl/pem.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#endif
/* Connection */
typedef struct fetchconn conn_t;
struct fetchconn {
int sd; /* socket descriptor */
char *buf; /* buffer */
size_t bufsize; /* buffer size */
size_t buflen; /* length of buffer contents */
int err; /* last protocol reply code */
#ifdef WITH_SSL
SSL *ssl; /* SSL handle */
SSL_CTX *ssl_ctx; /* SSL context */
X509 *ssl_cert; /* server certificate */
const SSL_METHOD *ssl_meth; /* SSL method */
#endif
int ref; /* reference count */
};
/* Structure used for error message lists */
struct fetcherr {
const int num;
const int cat;
const char *string;
};
/* For SOCKS header size */
#define HEAD_SIZE 4
#define FQDN_SIZE 256
#define PACK_SIZE 1
#define PORT_SIZE 2
#define BUFF_SIZE HEAD_SIZE + FQDN_SIZE + PACK_SIZE + PORT_SIZE
/* SOCKS5 Request Header */
#define SOCKS_VERSION_5 0x05
/* SOCKS5 CMD */
#define SOCKS_CONNECTION 0x01
#define SOCKS_BIND 0x02
#define SOCKS_UDP 0x03
#define SOCKS_NOMETHODS 0xFF
#define SOCKS5_NOTIMPLEMENTED 0x00
/* SOCKS5 Reserved */
#define SOCKS_RSV 0x00
/* SOCKS5 Address Type */
#define SOCKS_ATYP_IPV4 0x01
#define SOCKS_ATYP_DOMAINNAME 0x03
#define SOCKS_ATYP_IPV6 0x04
/* SOCKS5 Reply Field */
#define SOCKS_SUCCESS 0x00
#define SOCKS_GENERAL_FAILURE 0x01
#define SOCKS_CONNECTION_NOT_ALLOWED 0x02
#define SOCKS_NETWORK_UNREACHABLE 0x03
#define SOCKS_HOST_UNREACHABLE 0x04
#define SOCKS_CONNECTION_REFUSED 0x05
#define SOCKS_TTL_EXPIRED 0x06
#define SOCKS_COMMAND_NOT_SUPPORTED 0x07
#define SOCKS_ADDRESS_NOT_SUPPORTED 0x08
/* for fetch_writev */
struct iovec;
void fetch_seterr(struct fetcherr *, int);
void fetch_syserr(void);
void fetch_info(const char *, ...) __printflike(1, 2);
int fetch_socks5_getenv(char **host, int *port);
int fetch_socks5_init(conn_t *conn, const char *host,
int port, int verbose);
int fetch_default_port(const char *);
int fetch_default_proxy_port(const char *);
struct addrinfo *fetch_resolve(const char *, int, int);
int fetch_bind(int, int, const char *);
conn_t *fetch_connect(const char *, int, int, int);
conn_t *fetch_reopen(int);
conn_t *fetch_ref(conn_t *);
#ifdef WITH_SSL
int fetch_ssl_cb_verify_crt(int, X509_STORE_CTX*);
#endif
int fetch_ssl(conn_t *, const struct url *, int);
ssize_t fetch_read(conn_t *, char *, size_t);
int fetch_getln(conn_t *);
ssize_t fetch_write(conn_t *, const char *, size_t);
ssize_t fetch_writev(conn_t *, struct iovec *, int);
int fetch_putln(conn_t *, const char *, size_t);
int fetch_close(conn_t *);
int fetch_add_entry(struct url_ent **, int *, int *,
const char *, struct url_stat *);
int fetch_netrc_auth(struct url *url);
int fetch_no_proxy_match(const char *);
#define ftp_seterr(n) fetch_seterr(ftp_errlist, n)
#define http_seterr(n) fetch_seterr(http_errlist, n)
#define netdb_seterr(n) fetch_seterr(netdb_errlist, n)
#define url_seterr(n) fetch_seterr(url_errlist, n)
#define socks5_seterr(n) fetch_seterr(socks5_errlist, n)
#ifndef NDEBUG
#define DEBUGF(...) \
do { \
if (fetchDebug) \
fprintf(stderr, __VA_ARGS__); \
} while (0)
#else
#define DEBUGF(...) \
do { \
/* nothing */ \
} while (0)
#endif
/*
* I don't really like exporting http_request() and ftp_request(),
* but the HTTP and FTP code occasionally needs to cross-call
* eachother, and this saves me from adding a lot of special-case code
* to handle those cases.
*
* Note that _*_request() free purl, which is way ugly but saves us a
* whole lot of trouble.
*/
FILE *http_request(struct url *, const char *,
struct url_stat *, struct url *, const char *);
FILE *http_request_body(struct url *, const char *,
struct url_stat *, struct url *, const char *,
const char *, const char *);
FILE *ftp_request(struct url *, const char *,
struct url_stat *, struct url *, const char *);
/*
* Check whether a particular flag is set
*/
#define CHECK_FLAG(x) (flags && strchr(flags, (x)))
#endif