85 lines
2.5 KiB
C
85 lines
2.5 KiB
C
#include "util.h"
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#include "rlocs.h"
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#include <unistd.h>
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#include <errno.h>
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#include "packet.h"
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#include <sys/uio.h>
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/*
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* Entry point. Expects an invocation like:
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* unwrapper <filename of rloc database> <listen_ifname> <output_ifname>
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*/
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int main(int argc, char** argv)
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{
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struct session unwrap;
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struct recv_pkt recv_pkt;
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struct rsp_data to_send;
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ssize_t count;
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int result;
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if ( argc < 4 ) {
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warn( "Usage: %s <rloc database> <listen_ifname> <output_ifname>", argv[0] );
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return 1;
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}
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rlocs_init();
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if ( !session_setup( &unwrap, argv[1], argv[2], argv[3] ) ) {
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warn( "Failed to set up session, exiting" );
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return 1;
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}
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memset( &recv_pkt, 0, sizeof( struct recv_pkt ) );
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memset( &to_send, 0, sizeof( struct rsp_data ) );
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warn( "TODO: Write BGP interventions to file" );
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info( "Processing packets" );
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while(1) {
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// TODO: this isn't zero-copy. Not even close
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if ( ( count = read( unwrap.listen_if, &recv_pkt, sizeof( struct recv_pkt ) ) ) < 0 ) {
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warn( "Failed to get a packet (%s)", strerror( errno ) );
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break;
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}
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info( "Got a packet \\o/. %zu bytes", count );
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switch( recv_pkt.hdr.ip.version ) {
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case 0x04 :
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result = unwrap_ipv4_packet( unwrap.rlocs, &recv_pkt, &to_send );
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break;
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case 0x06 :
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result = unwrap_ipv6_packet( unwrap.rlocs, &recv_pkt, &to_send );
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break;
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default:
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warn( "Unknown IP version: %i", recv_pkt.hdr.ip.version );
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}
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// We can't send the unwrapped one - it'll just be returned to us
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// forever, given our bgp interventions, unless the router is clever.
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// TODO: make fallback-to-unwrapped a configurable option?
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if ( !result ) {
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warn( "Failed to unwrap received packet, dropping." );
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continue;
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}
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// no failure, but nothing to forward.
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if ( to_send.count == 0 ) {
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continue;
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}
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// docs say this should never block and should always write everything -
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// trust that for now.
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if ( ( count = writev( unwrap.output_if, to_send.iovs, to_send.count ) ) < 0 ) {
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warn( "Error writing unwrapped packet to output: %s", strerror(errno) );
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}
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}
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info( "Finished, cleaning up" );
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session_teardown( &unwrap );
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return 0;
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} |