bzr branch
http://bzr.recompile.se/loggerhead/mandos/release
237.25.4
by Teddy Hogeborn
Add plugin for mandos-client to add and delete local routes. |
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/* -*- coding: utf-8 -*- */
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/*
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* iprouteadddel - Add or delete direct route to a local IP address
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*
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* Copyright © 2015 Teddy Hogeborn
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* Copyright © 2015 Björn Påhlsson
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*
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* This program is free software: you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation, either version 3 of the
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* License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see
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* <http://www.gnu.org/licenses/>.
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*
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* Contact the authors at <mandos@recompile.se>.
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*/
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#define _GNU_SOURCE /* asprintf(), |
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program_invocation_short_name */
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#include <iso646.h> /* not, or, and */ |
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#include <stdbool.h> /* bool, false, true */ |
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#include <stdio.h> /* vfprintf(), stderr, stdout */ |
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#include <stdarg.h> /* va_list, va_start */ |
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#include <errno.h> /* perror(), errno, |
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program_invocation_short_name */ |
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#include <argp.h> /* struct argp_option, error_t, struct |
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argp_state, struct argp, |
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argp_parse(), ARGP_KEY_ARG, |
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ARGP_KEY_END, ARGP_ERR_UNKNOWN */ |
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#include <inttypes.h> /* PRIdMAX, intmax_t */ |
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#include <sysexits.h> /* EX_OSERR */ |
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/* #include <linux/netlink.h> */
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/* #include <netlink/netlink.h> */
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/* #include <netlink/socket.h> */
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#include <netlink/netlink.h> |
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#include <netlink/socket.h> |
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#include <netlink/cache.h> |
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#include <netlink/route/link.h> /* libnl xxx */ |
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#include <netlink/route/route.h> /* libnl xxx */ |
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bool debug = false; |
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const char *argp_program_version = "mandos-client-iprouteadddel " VERSION; |
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const char *argp_program_bug_address = "<mandos@recompile.se>"; |
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/* Function to use when printing errors */
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void perror_plus(const char *print_text){ |
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int e = errno; |
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fprintf(stderr, "Mandos plugin helper %s: ", |
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program_invocation_short_name); |
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errno = e; |
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perror(print_text); |
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}
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__attribute__((format (gnu_printf, 2, 3), nonnull)) |
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int fprintf_plus(FILE *stream, const char *format, ...){ |
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va_list ap; |
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va_start (ap, format); |
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fprintf(stream, "Mandos plugin helper %s: ", |
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program_invocation_short_name); |
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return vfprintf(stream, format, ap); |
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}
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int main(int argc, char *argv[]){ |
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int ret; |
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int exitcode = EXIT_SUCCESS; |
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struct arguments { |
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bool add; /* true: add, false: delete */ |
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char *address; /* IP address as string */ |
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struct nl_addr *nl_addr; /* Netlink IP address */ |
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char *interface; /* interface name */ |
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} arguments = { .add = true, .address = NULL, .interface = NULL }; |
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struct argp_option options[] = { |
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{ .name = "debug", .key = 128, |
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.doc = "Debug mode" }, |
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{ .name = NULL } |
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}; |
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struct rtnl_route *route = NULL; |
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struct rtnl_nexthop *nexthop = NULL; |
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struct nl_sock *sk = NULL; |
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error_t parse_opt(int key, char *arg, struct argp_state *state){ |
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int lret; |
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errno = 0; |
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switch(key){ |
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case 128: /* --debug */ |
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debug = true; |
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break; |
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case ARGP_KEY_ARG: |
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switch(state->arg_num){ |
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case 0: |
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if(strcasecmp(arg, "add") == 0){ |
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((struct arguments *)(state->input))->add = true; |
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} else if(strcasecmp(arg, "delete") == 0){ |
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((struct arguments *)(state->input))->add = false; |
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} else { |
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fprintf_plus(stderr, "Unrecognized command: %s\n", arg); |
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argp_usage(state); |
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} |
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break; |
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case 1: |
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((struct arguments *)(state->input))->address = arg; |
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lret = nl_addr_parse(arg, AF_UNSPEC, &(((struct arguments *) |
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(state->input)) |
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->nl_addr)); |
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if(lret != 0){ |
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fprintf_plus(stderr, "Failed to parse address %s: %s\n", |
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arg, nl_geterror(lret)); |
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argp_usage(state); |
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} |
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break; |
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case 2: |
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((struct arguments *)(state->input))->interface = arg; |
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break; |
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default: |
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argp_usage(state); |
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} |
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break; |
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case ARGP_KEY_END: |
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if(state->arg_num < 3){ |
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argp_usage(state); |
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} |
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break; |
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default: |
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return ARGP_ERR_UNKNOWN; |
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} |
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return errno; |
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} |
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struct argp argp = { .options = options, .parser = parse_opt, |
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.args_doc = "[ add | delete ] ADDRESS INTERFACE", |
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.doc = "Mandos client helper -- Add or delete" |
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" local route to IP address on interface" }; |
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ret = argp_parse(&argp, argc, argv, ARGP_IN_ORDER, 0, &arguments); |
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switch(ret){ |
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case 0: |
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break; |
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case EINVAL: |
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exit(EX_USAGE); |
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case ENOMEM: |
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default: |
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errno = ret; |
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perror_plus("argp_parse"); |
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exitcode = EX_OSERR; |
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goto end; |
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} |
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/* Get netlink socket */ |
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sk = nl_socket_alloc(); |
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if(sk == NULL){ |
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fprintf_plus(stderr, "Failed to allocate netlink socket: %s\n", |
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nl_geterror(ret)); |
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exitcode = EX_OSERR; |
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goto end; |
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} |
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/* Connect socket to netlink */ |
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ret = nl_connect(sk, NETLINK_ROUTE); |
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if(ret < 0){ |
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fprintf_plus(stderr, "Failed to connect socket to netlink: %s\n", |
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nl_geterror(ret)); |
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exitcode = EX_OSERR; |
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goto end; |
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} |
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/* Get link object of specified interface */ |
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struct rtnl_link *link = NULL; |
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ret = rtnl_link_get_kernel(sk, 0, arguments.interface, &link); |
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if(ret < 0){ |
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fprintf_plus(stderr, "Failed to use interface %s: %s\n", |
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arguments.interface, nl_geterror(ret)); |
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exitcode = EX_OSERR; |
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goto end; |
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} |
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/* Get netlink route object */ |
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route = rtnl_route_alloc(); |
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if(route == NULL){ |
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fprintf_plus(stderr, "Failed to get netlink route:\n"); |
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exitcode = EX_OSERR; |
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goto end; |
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} |
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/* Get address family of specified address */ |
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sa_family_t af = (sa_family_t)nl_addr_get_family(arguments.nl_addr); |
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if(debug){ |
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fprintf_plus(stderr, "Address family of %s is %s (%" PRIdMAX |
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")\n", arguments.address, |
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af == AF_INET6 ? "AF_INET6" : |
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( af == AF_INET ? "AF_INET" : "UNKNOWN"), |
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(intmax_t)af); |
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} |
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/* Set route parameters: */ |
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rtnl_route_set_family(route, (uint8_t)af); /* Address family */ |
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rtnl_route_set_protocol(route, RTPROT_BOOT); /* protocol - see |
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ip-route(8) */
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rtnl_route_set_scope(route, RT_SCOPE_LINK); /* link scope */ |
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rtnl_route_set_type(route, RTN_UNICAST); /* normal unicast |
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address route */
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rtnl_route_set_dst(route, arguments.nl_addr); /* Destination |
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address */
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rtnl_route_set_table(route, RT_TABLE_MAIN); /* "main" routing |
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table */
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/* Create nexthop */ |
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nexthop = rtnl_route_nh_alloc(); |
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if(nexthop == NULL){ |
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fprintf_plus(stderr, "Failed to get netlink route nexthop:\n"); |
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exitcode = EX_OSERR; |
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goto end; |
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} |
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/* Get index number of specified interface */ |
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int ifindex = rtnl_link_get_ifindex(link); |
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if(debug){ |
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fprintf_plus(stderr, "ifindex of %s is %d\n", arguments.interface, |
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ifindex); |
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} |
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/* Set interface index number on nexthop object */ |
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rtnl_route_nh_set_ifindex(nexthop, ifindex); |
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/* Set route tu use nexthop object */ |
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rtnl_route_add_nexthop(route, nexthop); |
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/* Add or delete route? */ |
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if(arguments.add){ |
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ret = rtnl_route_add(sk, route, NLM_F_EXCL); |
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} else { |
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ret = rtnl_route_delete(sk, route, 0); |
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} |
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if(ret < 0){ |
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fprintf_plus(stderr, "Failed to %s route: %s\n", |
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arguments.add ? "add" : "delete", |
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nl_geterror(ret)); |
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exitcode = EX_OSERR; |
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goto end; |
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} |
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end: |
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/* Deallocate route */ |
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if(route){ |
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rtnl_route_put(route); |
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} else if(nexthop) { |
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/* Deallocate route nexthop */ |
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rtnl_route_nh_free(nexthop); |
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} |
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/* Deallocate parsed address */ |
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if(arguments.nl_addr){ |
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nl_addr_put(arguments.nl_addr); |
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} |
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/* Deallocate link struct */ |
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if(link){ |
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rtnl_link_put(link); |
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} |
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/* Deallocate netlink socket struct */ |
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if(sk){ |
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nl_socket_free(sk); |
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} |
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return exitcode; |
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}
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