zcip: code shrink
function old new delta zcip_main 1263 1230 -33 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko
parent
16aa7a73c4
commit
99e30be38b
@ -215,19 +215,17 @@ int zcip_main(int argc UNUSED_PARAM, char **argv)
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const struct ether_addr null_addr;
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struct ifreq ifr;
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uint32_t chosen_nip;
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int timeout_ms; /* must be signed */
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int timeout_ms; // must be signed
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unsigned conflicts;
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unsigned nprobes;
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unsigned nclaims;
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unsigned nsent;
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int verbose;
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} L;
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#define null_addr (L.null_addr )
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#define chosen_nip (L.chosen_nip)
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#define ifr (L.ifr )
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#define chosen_nip (L.chosen_nip)
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#define timeout_ms (L.timeout_ms)
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#define conflicts (L.conflicts )
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#define nprobes (L.nprobes )
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#define nclaims (L.nclaims )
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#define nsent (L.nsent )
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#define verbose (L.verbose )
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memset(&L, 0, sizeof(L));
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@ -351,8 +349,7 @@ int zcip_main(int argc UNUSED_PARAM, char **argv)
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struct pollfd fds[1];
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unsigned deadline_us;
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struct arp_packet p;
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int source_ip_conflict;
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int target_ip_conflict;
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int ip_conflict;
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fds[0].fd = sock_fd;
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fds[0].events = POLLIN;
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@ -368,8 +365,8 @@ int zcip_main(int argc UNUSED_PARAM, char **argv)
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// set deadline_us to the point in time when we timeout
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deadline_us = MONOTONIC_US() + timeout_ms * 1000;
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VDBG("...wait %d %s nprobes=%u, nclaims=%u\n",
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timeout_ms, argv_intf, nprobes, nclaims);
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VDBG("...wait %d %s nsent=%u\n",
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timeout_ms, argv_intf, nsent);
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switch (safe_poll(fds, 1, timeout_ms)) {
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@ -384,10 +381,10 @@ int zcip_main(int argc UNUSED_PARAM, char **argv)
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case PROBE:
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// timeouts in the PROBE state mean no conflicting ARP packets
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// have been received, so we can progress through the states
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if (nprobes < PROBE_NUM) {
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nprobes++;
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if (nsent < PROBE_NUM) {
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nsent++;
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VDBG("probe/%u %s@%s\n",
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nprobes, argv_intf, nip_to_a(chosen_nip));
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nsent, argv_intf, nip_to_a(chosen_nip));
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timeout_ms = PROBE_MIN * 1000;
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timeout_ms += random_delay_ms(PROBE_MAX - PROBE_MIN);
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arp(/* ARPOP_REQUEST, */
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@ -395,25 +392,25 @@ int zcip_main(int argc UNUSED_PARAM, char **argv)
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&null_addr, chosen_nip);
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break;
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}
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// Switch to announce state.
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nclaims = 0;
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// Switch to announce state
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nsent = 0;
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state = ANNOUNCE;
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goto send_announce;
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case ANNOUNCE:
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// timeouts in the ANNOUNCE state mean no conflicting ARP packets
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// have been received, so we can progress through the states
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if (nclaims < ANNOUNCE_NUM) {
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if (nsent < ANNOUNCE_NUM) {
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send_announce:
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nclaims++;
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nsent++;
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VDBG("announce/%u %s@%s\n",
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nclaims, argv_intf, nip_to_a(chosen_nip));
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nsent, argv_intf, nip_to_a(chosen_nip));
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timeout_ms = ANNOUNCE_INTERVAL * 1000;
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arp(/* ARPOP_REQUEST, */
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/* &G.eth_addr, */ chosen_nip,
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&G.eth_addr, chosen_nip);
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break;
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}
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// Switch to monitor state.
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// Switch to monitor state
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// FIXME update filters
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run(argv, "config", chosen_nip);
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// NOTE: all other exit paths should deconfig...
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@ -424,7 +421,7 @@ int zcip_main(int argc UNUSED_PARAM, char **argv)
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state = MONITOR;
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break;
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case DEFEND:
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// Defend period ended with no ARP replies - we won.
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// Defend period ended with no ARP replies - we won
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conflicts = 0;
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timeout_ms = -1;
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state = MONITOR;
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@ -443,7 +440,7 @@ int zcip_main(int argc UNUSED_PARAM, char **argv)
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diff = 0;
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}
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VDBG("adjusting timeout\n");
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timeout_ms = (diff / 1000) | 1; /* never 0 */
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timeout_ms = (diff / 1000) | 1; // never 0
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}
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if ((fds[0].revents & POLLIN) == 0) {
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@ -452,7 +449,7 @@ int zcip_main(int argc UNUSED_PARAM, char **argv)
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// this shouldn't necessarily exit.
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bb_error_msg("iface %s is down", argv_intf);
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if (state >= MONITOR) {
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/* only if we are in MONITOR or DEFEND */
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// only if we are in MONITOR or DEFEND
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run(argv, "deconfig", chosen_nip);
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}
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return EXIT_FAILURE;
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@ -478,81 +475,65 @@ int zcip_main(int argc UNUSED_PARAM, char **argv)
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struct ether_addr *tha = (struct ether_addr *) p.arp.arp_tha;
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struct in_addr *spa = (struct in_addr *) p.arp.arp_spa;
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struct in_addr *tpa = (struct in_addr *) p.arp.arp_tpa;
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VDBG("%s recv arp type=%d, op=%d,\n",
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argv_intf, ntohs(p.eth.ether_type),
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ntohs(p.arp.arp_op));
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VDBG("\tsource=%s %s\n",
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ether_ntoa(sha),
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inet_ntoa(*spa));
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VDBG("\ttarget=%s %s\n",
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ether_ntoa(tha),
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inet_ntoa(*tpa));
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VDBG("source=%s %s\n", ether_ntoa(sha), inet_ntoa(*spa));
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VDBG("target=%s %s\n", ether_ntoa(tha), inet_ntoa(*tpa));
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}
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#endif
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source_ip_conflict = 0;
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target_ip_conflict = 0;
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ip_conflict = 0;
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if (memcmp(&p.arp.arp_sha, &G.eth_addr, ETH_ALEN) != 0) {
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if (memcmp(p.arp.arp_spa, &chosen_nip, 4) == 0) {
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/* A probe or reply with source_ip == chosen ip */
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source_ip_conflict = 1;
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// A probe or reply with source_ip == chosen ip
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ip_conflict = 1;
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}
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if (p.arp.arp_op == htons(ARPOP_REQUEST)
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&& memcmp(p.arp.arp_spa, &const_int_0, 4) == 0
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&& memcmp(p.arp.arp_tpa, &chosen_nip, 4) == 0
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) {
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/* A probe with source_ip == 0.0.0.0, target_ip == chosen ip:
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* another host trying to claim this ip!
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*/
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target_ip_conflict = 1;
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// A probe with source_ip == 0.0.0.0, target_ip == chosen ip:
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// another host trying to claim this ip!
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ip_conflict |= 2;
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}
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}
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VDBG("state = %d, source ip conflict = %d, target ip conflict = %d\n",
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state, source_ip_conflict, target_ip_conflict);
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switch (state) {
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case PROBE:
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case ANNOUNCE:
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// When probing or announcing, check for source IP conflicts
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// and other hosts doing ARP probes (target IP conflicts).
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if (source_ip_conflict || target_ip_conflict) {
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conflicts++;
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timeout_ms = PROBE_MIN * 1000
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+ CONFLICT_MULTIPLIER * random_delay_ms(conflicts);
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chosen_nip = pick_nip();
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nprobes = 0;
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nclaims = 0;
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state = PROBE;
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}
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VDBG("state:%d ip_conflict:%d\n", state, ip_conflict);
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if (!ip_conflict)
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break;
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case MONITOR:
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// If a conflict, we try to defend with a single ARP probe.
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if (source_ip_conflict) {
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VDBG("monitor conflict -- defending\n");
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// Either src or target IP conflict exists
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if (state <= ANNOUNCE) {
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// PROBE or ANNOUNCE
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conflicts++;
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timeout_ms = PROBE_MIN * 1000
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+ CONFLICT_MULTIPLIER * random_delay_ms(conflicts);
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chosen_nip = pick_nip();
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nsent = 0;
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state = PROBE;
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break;
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}
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// MONITOR or DEFEND: only src IP conflict is a problem
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if (ip_conflict & 1) {
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if (state == MONITOR) {
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// Src IP conflict, defend with a single ARP probe
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VDBG("monitor conflict - defending\n");
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timeout_ms = DEFEND_INTERVAL * 1000;
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state = DEFEND;
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arp(/* ARPOP_REQUEST, */
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/* &G.eth_addr, */ chosen_nip,
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&G.eth_addr, chosen_nip);
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break;
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}
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break;
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case DEFEND:
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// Well, we tried. Start over (on conflict).
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if (source_ip_conflict) {
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VDBG("defend conflict -- starting over\n");
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run(argv, "deconfig", chosen_nip);
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// state == DEFEND
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// Another src IP conflict, start over
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VDBG("defend conflict - starting over\n");
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run(argv, "deconfig", chosen_nip);
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// restart the whole protocol
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timeout_ms = 0;
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chosen_nip = pick_nip();
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nprobes = 0;
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nclaims = 0;
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state = PROBE;
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}
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break;
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} // switch state
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break; // case 1 (packets arriving)
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} // switch poll
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// restart the whole protocol
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timeout_ms = 0;
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chosen_nip = pick_nip();
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nsent = 0;
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state = PROBE;
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}
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break; // case 1 (packet arrived)
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} // switch (poll)
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} // while (1)
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#undef argv_intf
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}
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