src/openvpn/networking_iproute2.c - openvpn - Git at Google

 /*
  *  Networking API implementation for iproute2
  *
  *  Copyright (C) 2018-2021 Antonio Quartulli <a@unstable.cc>
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License version 2
  *  as published by the Free Software Foundation.
  *
  *  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 for more details.
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program (see the file COPYING included with this
  *  distribution); if not, write to the Free Software Foundation, Inc.,
  *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */

 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #elif defined(_MSC_VER)
 #include "config-msvc.h"
 #endif

 #if defined(TARGET_LINUX) && defined(ENABLE_IPROUTE)

 #include "syshead.h"

 #include "argv.h"
 #include "networking.h"
 #include "misc.h"
 #include "openvpn.h"
 #include "run_command.h"
 #include "socket.h"

 #include <stdbool.h>
 #include <netinet/in.h>

 int
 net_ctx_init(struct context *c, openvpn_net_ctx_t *ctx)
 {
     ctx->es = NULL;
     if (c)
     {
         ctx->es = c->es;
     }
     ctx->gc = gc_new();

     return 0;
 }

 void
 net_ctx_reset(openvpn_net_ctx_t *ctx)
 {
     gc_reset(&ctx->gc);
 }

 void
 net_ctx_free(openvpn_net_ctx_t *ctx)
 {
     gc_free(&ctx->gc);
 }

 int
 net_iface_up(openvpn_net_ctx_t *ctx, const char *iface, bool up)
 {
     struct argv argv = argv_new();

     argv_printf(&argv, "%s link set dev %s %s", iproute_path, iface,
                 up ? "up" : "down");
     argv_msg(M_INFO, &argv);
     openvpn_execve_check(&argv, ctx->es, S_FATAL, "Linux ip link set failed");

     argv_free(&argv);

     return 0;
 }

 int
 net_iface_mtu_set(openvpn_net_ctx_t *ctx, const char *iface, uint32_t mtu)
 {
     struct argv argv = argv_new();

     argv_printf(&argv, "%s link set dev %s up mtu %d", iproute_path, iface,
                 mtu);
     argv_msg(M_INFO, &argv);
     openvpn_execve_check(&argv, ctx->es, S_FATAL, "Linux ip link set failed");

     argv_free(&argv);

     return 0;
 }

 int
 net_addr_ll_set(openvpn_net_ctx_t *ctx, const openvpn_net_iface_t *iface,
                 uint8_t *addr)
 {
     struct argv argv = argv_new();
     int ret = 0;

     argv_printf(&argv,
                 "%s link set addr " MAC_FMT " dev %s",
                 iproute_path, MAC_PRINT_ARG(addr), iface);

     argv_msg(M_INFO, &argv);
     if (!openvpn_execve_check(&argv, ctx->es, M_WARN,
                               "Linux ip link set addr failed"))
     {
         ret = -1;
     }

     argv_free(&argv);

     return ret;
 }

 int
 net_addr_v4_add(openvpn_net_ctx_t *ctx, const char *iface,
                 const in_addr_t *addr, int prefixlen)
 {
     struct argv argv = argv_new();

     const char *addr_str = print_in_addr_t(*addr, 0, &ctx->gc);

     argv_printf(&argv, "%s addr add dev %s %s/%d", iproute_path, iface,
                 addr_str, prefixlen);
     argv_msg(M_INFO, &argv);
     openvpn_execve_check(&argv, ctx->es, S_FATAL, "Linux ip addr add failed");

     argv_free(&argv);

     return 0;
 }

 int
 net_addr_v6_add(openvpn_net_ctx_t *ctx, const char *iface,
                 const struct in6_addr *addr, int prefixlen)
 {
     struct argv argv = argv_new();
     char *addr_str = (char *)print_in6_addr(*addr, 0, &ctx->gc);

     argv_printf(&argv, "%s -6 addr add %s/%d dev %s", iproute_path, addr_str,
                 prefixlen, iface);
     argv_msg(M_INFO, &argv);
     openvpn_execve_check(&argv, ctx->es, S_FATAL,
                          "Linux ip -6 addr add failed");

     argv_free(&argv);

     return 0;
 }

 int
 net_addr_v4_del(openvpn_net_ctx_t *ctx, const char *iface,
                 const in_addr_t *addr, int prefixlen)
 {
     struct argv argv = argv_new();
     const char *addr_str = print_in_addr_t(*addr, 0, &ctx->gc);

     argv_printf(&argv, "%s addr del dev %s %s/%d", iproute_path, iface,
                 addr_str, prefixlen);

     argv_msg(M_INFO, &argv);
     openvpn_execve_check(&argv, ctx->es, 0, "Linux ip addr del failed");

     argv_free(&argv);

     return 0;
 }

 int
 net_addr_v6_del(openvpn_net_ctx_t *ctx, const char *iface,
                 const struct in6_addr *addr, int prefixlen)
 {
     struct argv argv = argv_new();
     char *addr_str = (char *)print_in6_addr(*addr, 0, &ctx->gc);

     argv_printf(&argv, "%s -6 addr del %s/%d dev %s", iproute_path,
                 addr_str, prefixlen, iface);
     argv_msg(M_INFO, &argv);
     openvpn_execve_check(&argv, ctx->es, 0, "Linux ip -6 addr del failed");

     argv_free(&argv);

     return 0;
 }

 int
 net_addr_ptp_v4_add(openvpn_net_ctx_t *ctx, const char *iface,
                     const in_addr_t *local, const in_addr_t *remote)
 {
     struct argv argv = argv_new();
     const char *local_str = print_in_addr_t(*local, 0, &ctx->gc);
     const char *remote_str = print_in_addr_t(*remote, 0, &ctx->gc);

     argv_printf(&argv, "%s addr add dev %s local %s peer %s", iproute_path,
                 iface, local_str, remote_str);
     argv_msg(M_INFO, &argv);
     openvpn_execve_check(&argv, ctx->es, S_FATAL, "Linux ip addr add failed");

     argv_free(&argv);

     return 0;
 }

 int
 net_addr_ptp_v4_del(openvpn_net_ctx_t *ctx, const char *iface,
                     const in_addr_t *local, const in_addr_t *remote)
 {
     struct argv argv = argv_new();
     const char *local_str = print_in_addr_t(*local, 0, &ctx->gc);
     const char *remote_str = print_in_addr_t(*remote, 0, &ctx->gc);

     argv_printf(&argv, "%s addr del dev %s local %s peer %s", iproute_path,
                 iface, local_str, remote_str);
     argv_msg(M_INFO, &argv);
     openvpn_execve_check(&argv, ctx->es, 0, "Linux ip addr del failed");

     argv_free(&argv);

     return 0;
 }

 int
 net_route_v4_add(openvpn_net_ctx_t *ctx, const in_addr_t *dst, int prefixlen,
                  const in_addr_t *gw, const char *iface, uint32_t table,
                  int metric)
 {
     struct argv argv = argv_new();
     const char *dst_str = print_in_addr_t(*dst, 0, &ctx->gc);

     argv_printf(&argv, "%s route add %s/%d", iproute_path, dst_str, prefixlen);

     if (metric > 0)
     {
         argv_printf_cat(&argv, "metric %d", metric);
     }

     if (iface)
     {
         argv_printf_cat(&argv, "dev %s", iface);
     }

     if (gw)
     {
         const char *gw_str = print_in_addr_t(*gw, 0, &ctx->gc);

         argv_printf_cat(&argv, "via %s", gw_str);
     }

     argv_msg(D_ROUTE, &argv);
     openvpn_execve_check(&argv, ctx->es, 0, "ERROR: Linux route add command failed");

     argv_free(&argv);

     return 0;
 }

 int
 net_route_v6_add(openvpn_net_ctx_t *ctx, const struct in6_addr *dst,
                  int prefixlen, const struct in6_addr *gw, const char *iface,
                  uint32_t table, int metric)
 {
     struct argv argv = argv_new();
     char *dst_str = (char *)print_in6_addr(*dst, 0, &ctx->gc);

     argv_printf(&argv, "%s -6 route add %s/%d dev %s", iproute_path, dst_str,
                 prefixlen, iface);

     if (gw)
     {
         char *gw_str = (char *)print_in6_addr(*gw, 0, &ctx->gc);

         argv_printf_cat(&argv, "via %s", gw_str);
     }

     if (metric > 0)
     {
         argv_printf_cat(&argv, "metric %d", metric);
     }

     argv_msg(D_ROUTE, &argv);
     openvpn_execve_check(&argv, ctx->es, 0, "ERROR: Linux route -6 add command failed");

     argv_free(&argv);

     return 0;
 }

 int
 net_route_v4_del(openvpn_net_ctx_t *ctx, const in_addr_t *dst, int prefixlen,
                  const in_addr_t *gw, const char *iface, uint32_t table,
                  int metric)
 {
     struct argv argv = argv_new();
     const char *dst_str = print_in_addr_t(*dst, 0, &ctx->gc);

     argv_printf(&argv, "%s route del %s/%d", iproute_path, dst_str, prefixlen);

     if (metric > 0)
     {
         argv_printf_cat(&argv, "metric %d", metric);
     }

     argv_msg(D_ROUTE, &argv);
     openvpn_execve_check(&argv, ctx->es, 0, "ERROR: Linux route delete command failed");

     argv_free(&argv);

     return 0;
 }

 int
 net_route_v6_del(openvpn_net_ctx_t *ctx, const struct in6_addr *dst,
                  int prefixlen, const struct in6_addr *gw, const char *iface,
                  uint32_t table, int metric)
 {
     struct argv argv = argv_new();
     char *dst_str = (char *)print_in6_addr(*dst, 0, &ctx->gc);

     argv_printf(&argv, "%s -6 route del %s/%d dev %s", iproute_path, dst_str,
                 prefixlen, iface);

     if (gw)
     {
         char *gw_str = (char *)print_in6_addr(*gw, 0, &ctx->gc);

         argv_printf_cat(&argv, "via %s", gw_str);
     }

     if (metric > 0)
     {
         argv_printf_cat(&argv, "metric %d", metric);
     }

     argv_msg(D_ROUTE, &argv);
     openvpn_execve_check(&argv, ctx->es, 0, "ERROR: Linux route -6 del command failed");

     argv_free(&argv);

     return 0;
 }

 int
 net_route_v4_best_gw(openvpn_net_ctx_t *ctx, const in_addr_t *dst,
                      in_addr_t *best_gw, char *best_iface)
 {
     best_iface[0] = '\0';

     FILE *fp = fopen("/proc/net/route", "r");
     if (!fp)
     {
         return -1;
     }

     char line[256];
     int count = 0;
     unsigned int lowest_metric = UINT_MAX;
     while (fgets(line, sizeof(line), fp) != NULL)
     {
         if (count)
         {
             unsigned int net_x = 0;
             unsigned int mask_x = 0;
             unsigned int gw_x = 0;
             unsigned int metric = 0;
             unsigned int flags = 0;
             char name[16];
             name[0] = '\0';

             const int np = sscanf(line, "%15s\t%x\t%x\t%x\t%*s\t%*s\t%d\t%x",
                                   name, &net_x, &gw_x, &flags, &metric,
                                   &mask_x);

             if (np == 6 && (flags & IFF_UP))
             {
                 const in_addr_t net = ntohl(net_x);
                 const in_addr_t mask = ntohl(mask_x);
                 const in_addr_t gw = ntohl(gw_x);

                 if (!net && !mask && metric < lowest_metric)
                 {
                     *best_gw = gw;
                     strcpy(best_iface, name);
                     lowest_metric = metric;
                 }
             }
         }
         ++count;
     }
     fclose(fp);

     return 0;
 }

 /*
  * The following function is not implemented in the iproute backend as it
  * uses the sitnl implementation from networking_sitnl.c.
  *
  * int
  * net_route_v6_best_gw(const struct in6_addr *dst,
  *                      struct in6_addr *best_gw, char *best_iface)
  */

 #endif /* ENABLE_IPROUTE && TARGET_LINUX */
	/*
	* Networking API implementation for iproute2
	*
	* Copyright (C) 2018-2021 Antonio Quartulli <a@unstable.cc>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2
	* as published by the Free Software Foundation.
	*
	* 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 for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program (see the file COPYING included with this
	* distribution); if not, write to the Free Software Foundation, Inc.,
	* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	#ifdef HAVE_CONFIG_H
	#include "config.h"
	#elif defined(_MSC_VER)
	#include "config-msvc.h"
	#endif

	#if defined(TARGET_LINUX) && defined(ENABLE_IPROUTE)

	#include "syshead.h"

	#include "argv.h"
	#include "networking.h"
	#include "misc.h"
	#include "openvpn.h"
	#include "run_command.h"
	#include "socket.h"

	#include <stdbool.h>
	#include <netinet/in.h>

	int
	net_ctx_init(struct context c, openvpn_net_ctx_t ctx)
	{
	ctx->es = NULL;
	if (c)
	{
	ctx->es = c->es;
	}
	ctx->gc = gc_new();

	return 0;
	}

	void
	net_ctx_reset(openvpn_net_ctx_t *ctx)
	{
	gc_reset(&ctx->gc);
	}

	void
	net_ctx_free(openvpn_net_ctx_t *ctx)
	{
	gc_free(&ctx->gc);
	}

	int
	net_iface_up(openvpn_net_ctx_t ctx, const char iface, bool up)
	{
	struct argv argv = argv_new();

	argv_printf(&argv, "%s link set dev %s %s", iproute_path, iface,
	up ? "up" : "down");
	argv_msg(M_INFO, &argv);
	openvpn_execve_check(&argv, ctx->es, S_FATAL, "Linux ip link set failed");

	argv_free(&argv);

	return 0;
	}

	int
	net_iface_mtu_set(openvpn_net_ctx_t ctx, const char iface, uint32_t mtu)
	{
	struct argv argv = argv_new();

	argv_printf(&argv, "%s link set dev %s up mtu %d", iproute_path, iface,
	mtu);
	argv_msg(M_INFO, &argv);
	openvpn_execve_check(&argv, ctx->es, S_FATAL, "Linux ip link set failed");

	argv_free(&argv);

	return 0;
	}

	int
	net_addr_ll_set(openvpn_net_ctx_t ctx, const openvpn_net_iface_t iface,
	uint8_t *addr)
	{
	struct argv argv = argv_new();
	int ret = 0;

	argv_printf(&argv,
	"%s link set addr " MAC_FMT " dev %s",
	iproute_path, MAC_PRINT_ARG(addr), iface);

	argv_msg(M_INFO, &argv);
	if (!openvpn_execve_check(&argv, ctx->es, M_WARN,
	"Linux ip link set addr failed"))
	{
	ret = -1;
	}

	argv_free(&argv);

	return ret;
	}

	int
	net_addr_v4_add(openvpn_net_ctx_t ctx, const char iface,
	const in_addr_t *addr, int prefixlen)
	{
	struct argv argv = argv_new();

	const char addr_str = print_in_addr_t(addr, 0, &ctx->gc);

	argv_printf(&argv, "%s addr add dev %s %s/%d", iproute_path, iface,
	addr_str, prefixlen);
	argv_msg(M_INFO, &argv);
	openvpn_execve_check(&argv, ctx->es, S_FATAL, "Linux ip addr add failed");

	argv_free(&argv);

	return 0;
	}

	int
	net_addr_v6_add(openvpn_net_ctx_t ctx, const char iface,
	const struct in6_addr *addr, int prefixlen)
	{
	struct argv argv = argv_new();
	char addr_str = (char )print_in6_addr(*addr, 0, &ctx->gc);

	argv_printf(&argv, "%s -6 addr add %s/%d dev %s", iproute_path, addr_str,
	prefixlen, iface);
	argv_msg(M_INFO, &argv);
	openvpn_execve_check(&argv, ctx->es, S_FATAL,
	"Linux ip -6 addr add failed");

	argv_free(&argv);

	return 0;
	}

	int
	net_addr_v4_del(openvpn_net_ctx_t ctx, const char iface,
	const in_addr_t *addr, int prefixlen)
	{
	struct argv argv = argv_new();
	const char addr_str = print_in_addr_t(addr, 0, &ctx->gc);

	argv_printf(&argv, "%s addr del dev %s %s/%d", iproute_path, iface,
	addr_str, prefixlen);

	argv_msg(M_INFO, &argv);
	openvpn_execve_check(&argv, ctx->es, 0, "Linux ip addr del failed");

	argv_free(&argv);

	return 0;
	}

	int
	net_addr_v6_del(openvpn_net_ctx_t ctx, const char iface,
	const struct in6_addr *addr, int prefixlen)
	{
	struct argv argv = argv_new();
	char addr_str = (char )print_in6_addr(*addr, 0, &ctx->gc);

	argv_printf(&argv, "%s -6 addr del %s/%d dev %s", iproute_path,
	addr_str, prefixlen, iface);
	argv_msg(M_INFO, &argv);
	openvpn_execve_check(&argv, ctx->es, 0, "Linux ip -6 addr del failed");

	argv_free(&argv);

	return 0;
	}

	int
	net_addr_ptp_v4_add(openvpn_net_ctx_t ctx, const char iface,
	const in_addr_t local, const in_addr_t remote)
	{
	struct argv argv = argv_new();
	const char local_str = print_in_addr_t(local, 0, &ctx->gc);
	const char remote_str = print_in_addr_t(remote, 0, &ctx->gc);

	argv_printf(&argv, "%s addr add dev %s local %s peer %s", iproute_path,
	iface, local_str, remote_str);
	argv_msg(M_INFO, &argv);
	openvpn_execve_check(&argv, ctx->es, S_FATAL, "Linux ip addr add failed");

	argv_free(&argv);

	return 0;
	}

	int
	net_addr_ptp_v4_del(openvpn_net_ctx_t ctx, const char iface,
	const in_addr_t local, const in_addr_t remote)
	{
	struct argv argv = argv_new();
	const char local_str = print_in_addr_t(local, 0, &ctx->gc);
	const char remote_str = print_in_addr_t(remote, 0, &ctx->gc);

	argv_printf(&argv, "%s addr del dev %s local %s peer %s", iproute_path,
	iface, local_str, remote_str);
	argv_msg(M_INFO, &argv);
	openvpn_execve_check(&argv, ctx->es, 0, "Linux ip addr del failed");

	argv_free(&argv);

	return 0;
	}

	int
	net_route_v4_add(openvpn_net_ctx_t ctx, const in_addr_t dst, int prefixlen,
	const in_addr_t gw, const char iface, uint32_t table,
	int metric)
	{
	struct argv argv = argv_new();
	const char dst_str = print_in_addr_t(dst, 0, &ctx->gc);

	argv_printf(&argv, "%s route add %s/%d", iproute_path, dst_str, prefixlen);

	if (metric > 0)
	{
	argv_printf_cat(&argv, "metric %d", metric);
	}

	if (iface)
	{
	argv_printf_cat(&argv, "dev %s", iface);
	}

	if (gw)
	{
	const char gw_str = print_in_addr_t(gw, 0, &ctx->gc);

	argv_printf_cat(&argv, "via %s", gw_str);
	}

	argv_msg(D_ROUTE, &argv);
	openvpn_execve_check(&argv, ctx->es, 0, "ERROR: Linux route add command failed");

	argv_free(&argv);

	return 0;
	}

	int
	net_route_v6_add(openvpn_net_ctx_t ctx, const struct in6_addr dst,
	int prefixlen, const struct in6_addr gw, const char iface,
	uint32_t table, int metric)
	{
	struct argv argv = argv_new();
	char dst_str = (char )print_in6_addr(*dst, 0, &ctx->gc);

	argv_printf(&argv, "%s -6 route add %s/%d dev %s", iproute_path, dst_str,
	prefixlen, iface);

	if (gw)
	{
	char gw_str = (char )print_in6_addr(*gw, 0, &ctx->gc);

	argv_printf_cat(&argv, "via %s", gw_str);
	}

	if (metric > 0)
	{
	argv_printf_cat(&argv, "metric %d", metric);
	}

	argv_msg(D_ROUTE, &argv);
	openvpn_execve_check(&argv, ctx->es, 0, "ERROR: Linux route -6 add command failed");

	argv_free(&argv);

	return 0;
	}

	int
	net_route_v4_del(openvpn_net_ctx_t ctx, const in_addr_t dst, int prefixlen,
	const in_addr_t gw, const char iface, uint32_t table,
	int metric)
	{
	struct argv argv = argv_new();
	const char dst_str = print_in_addr_t(dst, 0, &ctx->gc);

	argv_printf(&argv, "%s route del %s/%d", iproute_path, dst_str, prefixlen);

	if (metric > 0)
	{
	argv_printf_cat(&argv, "metric %d", metric);
	}

	argv_msg(D_ROUTE, &argv);
	openvpn_execve_check(&argv, ctx->es, 0, "ERROR: Linux route delete command failed");

	argv_free(&argv);

	return 0;
	}

	int
	net_route_v6_del(openvpn_net_ctx_t ctx, const struct in6_addr dst,
	int prefixlen, const struct in6_addr gw, const char iface,
	uint32_t table, int metric)
	{
	struct argv argv = argv_new();
	char dst_str = (char )print_in6_addr(*dst, 0, &ctx->gc);

	argv_printf(&argv, "%s -6 route del %s/%d dev %s", iproute_path, dst_str,
	prefixlen, iface);

	if (gw)
	{
	char gw_str = (char )print_in6_addr(*gw, 0, &ctx->gc);

	argv_printf_cat(&argv, "via %s", gw_str);
	}

	if (metric > 0)
	{
	argv_printf_cat(&argv, "metric %d", metric);
	}

	argv_msg(D_ROUTE, &argv);
	openvpn_execve_check(&argv, ctx->es, 0, "ERROR: Linux route -6 del command failed");

	argv_free(&argv);

	return 0;
	}

	int
	net_route_v4_best_gw(openvpn_net_ctx_t ctx, const in_addr_t dst,
	in_addr_t best_gw, char best_iface)
	{
	best_iface[0] = '\0';

	FILE *fp = fopen("/proc/net/route", "r");
	if (!fp)
	{
	return -1;
	}

	char line[256];
	int count = 0;
	unsigned int lowest_metric = UINT_MAX;
	while (fgets(line, sizeof(line), fp) != NULL)
	{
	if (count)
	{
	unsigned int net_x = 0;
	unsigned int mask_x = 0;
	unsigned int gw_x = 0;
	unsigned int metric = 0;
	unsigned int flags = 0;
	char name[16];
	name[0] = '\0';

	const int np = sscanf(line, "%15s\t%x\t%x\t%x\t%s\t%s\t%d\t%x",
	name, &net_x, &gw_x, &flags, &metric,
	&mask_x);

	if (np == 6 && (flags & IFF_UP))
	{
	const in_addr_t net = ntohl(net_x);
	const in_addr_t mask = ntohl(mask_x);
	const in_addr_t gw = ntohl(gw_x);

	if (!net && !mask && metric < lowest_metric)
	{
	*best_gw = gw;
	strcpy(best_iface, name);
	lowest_metric = metric;
	}
	}
	}
	++count;
	}
	fclose(fp);

	return 0;
	}

	/*
	* The following function is not implemented in the iproute backend as it
	* uses the sitnl implementation from networking_sitnl.c.
	*
	* int
	* net_route_v6_best_gw(const struct in6_addr *dst,
	* struct in6_addr best_gw, char best_iface)
	*/

	#endif /* ENABLE_IPROUTE && TARGET_LINUX */