diff options
author | Rob Landley <rob@landley.net> | 2005-05-03 07:28:55 +0400 |
---|---|---|
committer | Rob Landley <rob@landley.net> | 2005-05-03 07:28:55 +0400 |
commit | e3752e56a43a823f4aaaa9a4374ccc367417b942 (patch) | |
tree | b954cd7801fd3a30f8a5231ee0106c8db11da568 /networking/zcip.c | |
parent | 8445a9ff99f04cad8845a1aed6ab17737f2d985a (diff) |
Revert Tito's patch to zcip. My bad, David Brownell had objected and I missed
it...
Diffstat (limited to 'networking/zcip.c')
-rw-r--r-- | networking/zcip.c | 295 |
1 files changed, 186 insertions, 109 deletions
diff --git a/networking/zcip.c b/networking/zcip.c index de9ea7675..ccf399bb7 100644 --- a/networking/zcip.c +++ b/networking/zcip.c @@ -31,12 +31,14 @@ * certainly be used. Its naming is built over multicast DNS. */ -/* TODO: - - more real-world usage/testing, especially daemon mode - - kernel packet filters to reduce scheduling noise - - avoid silent script failures, especially under load... - - link status monitoring (restart on link-up; stop on link-down) -*/ +// #define DEBUG + +// TODO: +// - more real-world usage/testing, especially daemon mode +// - kernel packet filters to reduce scheduling noise +// - avoid silent script failures, especially under load... +// - link status monitoring (restart on link-up; stop on link-down) + #include <errno.h> #include <stdlib.h> #include <stdio.h> @@ -61,12 +63,11 @@ #include <linux/if_packet.h> #include <linux/sockios.h> -#include "busybox.h" -#include "libbb.h" + struct arp_packet { struct ether_header hdr; - /* FIXME this part is netinet/if_ether.h "struct ether_arp" */ + // FIXME this part is netinet/if_ether.h "struct ether_arp" struct arphdr arp; struct ether_addr source_addr; struct in_addr source_ip; @@ -89,13 +90,29 @@ static const unsigned ANNOUNCE_NUM = 2; static const unsigned ANNOUNCE_INTERVAL = 2; static const time_t DEFEND_INTERVAL = 10; -#define ZCIP_VERSION "0.75 (18 April 2005)" +static const unsigned char ZCIP_VERSION[] = "0.75 (18 April 2005)"; +static char *prog; static const struct in_addr null_ip = { 0 }; static const struct ether_addr null_addr = { {0, 0, 0, 0, 0, 0} }; +static int verbose = 0; -/* +#ifdef DEBUG + +#define DBG(fmt,args...) \ + fprintf(stderr, "%s: " fmt , prog , ## args) +#define VDBG(fmt,args...) do { \ + if (verbose) fprintf(stderr, "%s: " fmt , prog ,## args); \ + } while (0) +#else + +#define DBG(fmt,args...) \ + do { } while (0) +#define VDBG DBG +#endif /* DEBUG */ + +/** * Pick a random link local IP address on 169.254/16, except that * the first and last 256 addresses are reserved. */ @@ -111,7 +128,7 @@ pick(struct in_addr *ip) ip->s_addr = htonl((LINKLOCAL_ADDR + 0x0100) + tmp); } -/* +/** * Broadcast an ARP packet. */ static int @@ -121,12 +138,12 @@ arp(int fd, struct sockaddr *saddr, int op, { struct arp_packet p; - /* ether header */ + // ether header p.hdr.ether_type = htons(ETHERTYPE_ARP); memcpy(p.hdr.ether_shost, source_addr, ETH_ALEN); memset(p.hdr.ether_dhost, 0xff, ETH_ALEN); - /* arp request */ + // arp request p.arp.ar_hrd = htons(ARPHRD_ETHER); p.arp.ar_pro = htons(ETHERTYPE_IP); p.arp.ar_hln = ETH_ALEN; @@ -137,15 +154,15 @@ arp(int fd, struct sockaddr *saddr, int op, memcpy(&p.target_addr, target_addr, ETH_ALEN); memcpy(&p.target_ip, &target_ip, sizeof (p.target_ip)); - /* send it */ + // send it if (sendto(fd, &p, sizeof (p), 0, saddr, sizeof (*saddr)) < 0) { - bb_perror_msg("sendto"); + perror("sendto"); return -errno; } return 0; } -/* +/** * Run a script. */ static int @@ -155,19 +172,21 @@ run(char *script, char *arg, char *intf, struct in_addr *ip) char *why; if (script != NULL) { + VDBG("%s run %s %s\n", intf, script, arg); if (ip != NULL) { char *addr = inet_ntoa(*ip); - xsetenv("ip", addr); + setenv("ip", addr, 1); syslog(LOG_INFO, "%s %s %s", arg, intf, addr); } pid = vfork(); - if (pid < 0) { /* error */ + if (pid < 0) { // error why = "vfork"; goto bad; - } else if (pid == 0) { /* child */ + } else if (pid == 0) { // child execl(script, script, arg, NULL); - bb_perror_msg_and_die("execl"); + perror("execl"); + _exit(EXIT_FAILURE); } if (waitpid(pid, &status, 0) <= 0) { @@ -175,7 +194,8 @@ run(char *script, char *arg, char *intf, struct in_addr *ip) goto bad; } if (WEXITSTATUS(status) != 0) { - bb_perror_msg("script %s failed, exit=%d", script, WEXITSTATUS(status)); + fprintf(stderr, "%s: script %s failed, exit=%d\n", + prog, script, WEXITSTATUS(status)); return -errno; } } @@ -187,7 +207,31 @@ bad: return status; } -/* +#ifndef NO_BUSYBOX +#include "busybox.h" +#endif + +/** + * Print usage information. + */ +static void __attribute__ ((noreturn)) +usage(const char *msg) +{ + fprintf(stderr, "%s: %s\n", prog, msg); +#ifdef NO_BUSYBOX + fprintf(stderr, "Usage: %s [OPTIONS] ifname script\n" + "\t-f foreground mode (implied by -v)\n" + "\t-q quit after address (no daemon)\n" + "\t-r 169.254.x.x request this address first\n" + "\t-v verbose; show version\n", + prog); + exit(0); +#else + bb_show_usage(); +#endif +} + +/** * Return milliseconds of random delay, up to "secs" seconds. */ static inline unsigned @@ -196,72 +240,85 @@ ms_rdelay(unsigned secs) return lrand48() % (secs * 1000); } -/* +/** * main program */ - -#define FOREGROUND 1 -#define QUIT 2 -#define REQUEST 4 -#define VERBOSE 8 +int +main(int argc, char *argv[]) + __attribute__ ((weak, alias ("zcip_main"))); int zcip_main(int argc, char *argv[]) { char *intf = NULL; char *script = NULL; + int quit = 0; + int foreground = 0; + char *why; struct sockaddr saddr; struct ether_addr addr; struct in_addr ip = { 0 }; int fd; int ready = 0; - suseconds_t timeout = 0; /* milliseconds */ + suseconds_t timeout = 0; // milliseconds time_t defend = 0; unsigned conflicts = 0; unsigned nprobes = 0; unsigned nclaims = 0; - unsigned long t; - - bb_opt_complementaly = "vf"; - /* parse commandline: prog [options] ifname script */ - t = bb_getopt_ulflags(argc, argv, "fqr:v", &why); /* reuse char* why */ - - argc -= optind; - argv += optind; - - if ((t & 0x80000000UL) || (argc < 1) || (argc > 2)) { - bb_show_usage(); - } - - if (t & VERBOSE) { - bb_printf("%s: version %s\n", bb_applet_name, ZCIP_VERSION); + int t; + + // parse commandline: prog [options] ifname script + prog = argv[0]; + while ((t = getopt(argc, argv, "fqr:v")) != EOF) { + switch (t) { + case 'f': + foreground = 1; + continue; + case 'q': + quit = 1; + continue; + case 'r': + if (inet_aton(optarg, &ip) == 0 + || (ntohl(ip.s_addr) & IN_CLASSB_NET) + != LINKLOCAL_ADDR) { + usage("invalid link address"); + } + continue; + case 'v': + if (!verbose) + printf("%s: version %s\n", prog, ZCIP_VERSION); + verbose++; + foreground = 1; + continue; + default: + usage("bad option"); + } } - if ((t & REQUEST) && (inet_aton(why, &ip) == 0 || (ntohl(ip.s_addr) & IN_CLASSB_NET) != LINKLOCAL_ADDR)) { - bb_perror_msg_and_die("invalid link address"); + if (optind < argc - 1) { + intf = argv[optind++]; + setenv("interface", intf, 1); + script = argv[optind++]; } - - intf = argv[0]; - xsetenv("interface", intf); - script = argv[1]; /* Could be NULL ? */ - - openlog(bb_applet_name, 0, LOG_DAEMON); - - /* initialize the interface (modprobe, ifup, etc) */ + if (optind != argc || !intf) + usage("wrong number of arguments"); + openlog(prog, 0, LOG_DAEMON); + + // initialize the interface (modprobe, ifup, etc) if (run(script, "init", intf, NULL) < 0) return EXIT_FAILURE; - /* initialize saddr */ + // initialize saddr memset(&saddr, 0, sizeof (saddr)); strncpy(saddr.sa_data, intf, sizeof (saddr.sa_data)); - /* open an ARP socket */ + // open an ARP socket if ((fd = socket(PF_PACKET, SOCK_PACKET, htons(ETH_P_ARP))) < 0) { why = "open"; fail: - t |= FOREGROUND; + foreground = 1; goto bad; } - /* bind to the interface's ARP socket */ + // bind to the interface's ARP socket if (bind(fd, &saddr, sizeof (saddr)) < 0) { why = "bind"; goto fail; @@ -269,7 +326,7 @@ fail: struct ifreq ifr; short seed[3]; - /* get the interface's ethernet address */ + // get the interface's ethernet address memset(&ifr, 0, sizeof (ifr)); strncpy(ifr.ifr_name, intf, sizeof (ifr.ifr_name)); if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) { @@ -278,37 +335,37 @@ fail: } memcpy(&addr, &ifr.ifr_hwaddr.sa_data, ETH_ALEN); - /* start with some stable ip address, either a function of - the hardware address or else the last address we used. - NOTE: the sequence of addresses we try changes only - depending on when we detect conflicts. */ + // start with some stable ip address, either a function of + // the hardware address or else the last address we used. + // NOTE: the sequence of addresses we try changes only + // depending on when we detect conflicts. memcpy(seed, &ifr.ifr_hwaddr.sa_data, ETH_ALEN); seed48(seed); if (ip.s_addr == 0) pick(&ip); } - /* FIXME cases to handle: - - zcip already running! - - link already has local address... just defend/update */ + // FIXME cases to handle: + // - zcip already running! + // - link already has local address... just defend/update - /* daemonize now; don't delay system startup */ - if (!(t & FOREGROUND)) { - if (daemon(0, (t & VERBOSE)) < 0) { + // daemonize now; don't delay system startup + if (!foreground) { + if (daemon(0, verbose) < 0) { why = "daemon"; goto bad; } syslog(LOG_INFO, "start, interface %s", intf); } - /* run the dynamic address negotiation protocol, - restarting after address conflicts: - - start with some address we want to try - - short random delay - - arp probes to see if another host else uses it - - arp announcements that we're claiming it - - use it - - defend it, within limits */ + // run the dynamic address negotiation protocol, + // restarting after address conflicts: + // - start with some address we want to try + // - short random delay + // - arp probes to see if another host else uses it + // - arp announcements that we're claiming it + // - use it + // - defend it, within limits while (1) { struct pollfd fds[1]; struct timeval tv1; @@ -318,7 +375,7 @@ fail: fds[0].events = POLLIN; fds[0].revents = 0; - /* poll, being ready to adjust current timeout */ + // poll, being ready to adjust current timeout if (timeout > 0) { gettimeofday(&tv1, NULL); tv1.tv_usec += (timeout % 1000) * 1000; @@ -329,17 +386,21 @@ fail: tv1.tv_sec += timeout / 1000; } else if (timeout == 0) { timeout = ms_rdelay(PROBE_WAIT); - /* FIXME setsockopt(fd, SO_ATTACH_FILTER, ...) to - make the kernel filter out all packets except - ones we'd care about. */ + // FIXME setsockopt(fd, SO_ATTACH_FILTER, ...) to + // make the kernel filter out all packets except + // ones we'd care about. } + VDBG("...wait %ld %s nprobes=%d, nclaims=%d\n", + timeout, intf, nprobes, nclaims); switch (poll(fds, 1, timeout)) { - /* timeouts trigger protocol transitions */ + // timeouts trigger protocol transitions case 0: - /* probes */ + // probes if (nprobes < PROBE_NUM) { nprobes++; + VDBG("probe/%d %s@%s\n", + nprobes, intf, inet_ntoa(ip)); (void)arp(fd, &saddr, ARPOP_REQUEST, &addr, null_ip, &null_addr, ip); @@ -350,36 +411,38 @@ fail: } else timeout = ANNOUNCE_WAIT * 1000; } - /* then announcements */ + // then announcements else if (nclaims < ANNOUNCE_NUM) { nclaims++; + VDBG("announce/%d %s@%s\n", + nclaims, intf, inet_ntoa(ip)); (void)arp(fd, &saddr, ARPOP_REQUEST, &addr, ip, &addr, ip); if (nclaims < ANNOUNCE_NUM) { timeout = ANNOUNCE_INTERVAL * 1000; } else { - /* link is ok to use earlier */ + // link is ok to use earlier run(script, "config", intf, &ip); ready = 1; conflicts = 0; timeout = -1; - /* NOTE: all other exit paths - should deconfig ... */ - if (t & QUIT) + // NOTE: all other exit paths + // should deconfig ... + if (quit) return EXIT_SUCCESS; - /* FIXME update filters */ + // FIXME update filters } } break; - /* packets arriving */ + // packets arriving case 1: - /* maybe adjust timeout */ + // maybe adjust timeout if (timeout > 0) { struct timeval tv2; - + gettimeofday(&tv2, NULL); if (timercmp(&tv1, &tv2, <)) { timeout = -1; @@ -391,33 +454,46 @@ fail: } if ((fds[0].revents & POLLIN) == 0) { if (fds[0].revents & POLLERR) { - /* FIXME: links routinely go down; - this shouldn't necessarily exit. */ - bb_perror_msg("%s: poll error", intf); + // FIXME: links routinely go down; + // this shouldn't necessarily exit. + fprintf(stderr, "%s %s: poll error\n", + prog, intf); if (ready) { - run(script, "deconfig", intf, &ip); + run(script, "deconfig", + intf, &ip); } return EXIT_FAILURE; } continue; } - /* read ARP packet */ + // read ARP packet if (recv(fd, &p, sizeof (p), 0) < 0) { why = "recv"; goto bad; } if (p.hdr.ether_type != htons(ETHERTYPE_ARP)) continue; - + + VDBG("%s recv arp type=%d, op=%d,\n", + intf, ntohs(p.hdr.ether_type), + ntohs(p.arp.ar_op)); + VDBG("\tsource=%s %s\n", + ether_ntoa(&p.source_addr), + inet_ntoa(p.source_ip)); + VDBG("\ttarget=%s %s\n", + ether_ntoa(&p.target_addr), + inet_ntoa(p.target_ip)); if (p.arp.ar_op != htons(ARPOP_REQUEST) && p.arp.ar_op != htons(ARPOP_REPLY)) continue; - /* some cases are always conflicts */ + // some cases are always conflicts if ((p.source_ip.s_addr == ip.s_addr) && (memcmp(&addr, &p.source_addr, ETH_ALEN) != 0)) { collision: + VDBG("%s ARP conflict from %s\n", intf, + ether_ntoa(&p.source_addr)); if (ready) { time_t now = time(0); @@ -428,26 +504,28 @@ collision: ARPOP_REQUEST, &addr, ip, &addr, ip); + VDBG("%s defend\n", intf); timeout = -1; continue; } defend = now; ready = 0; run(script, "deconfig", intf, &ip); - /* FIXME rm filters: setsockopt(fd, - SO_DETACH_FILTER, ...) */ + // FIXME rm filters: setsockopt(fd, + // SO_DETACH_FILTER, ...) } conflicts++; if (conflicts >= MAX_CONFLICTS) { + VDBG("%s ratelimit\n", intf); sleep(RATE_LIMIT_INTERVAL); } - /* restart the whole protocol */ + // restart the whole protocol pick(&ip); timeout = 0; nprobes = 0; nclaims = 0; } - /* two hosts probing one address is a collision too */ + // two hosts probing one address is a collision too else if (p.target_ip.s_addr == ip.s_addr && nclaims == 0 && p.arp.ar_op == htons(ARPOP_REQUEST) @@ -463,11 +541,10 @@ collision: } } bad: - if ( t & FOREGROUND) { - bb_perror_msg(why); - } else { + if (foreground) + perror(why); + else syslog(LOG_ERR, "%s %s, %s error: %s", - bb_applet_name, intf, why, strerror(errno)); - } + prog, intf, why, strerror(errno)); return EXIT_FAILURE; } |