* certainly be used. Its naming is built over multicast DNS.
*/
-// #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)
-
+/* 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>
#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;
static const unsigned ANNOUNCE_INTERVAL = 2;
static const time_t DEFEND_INTERVAL = 10;
-static const unsigned char ZCIP_VERSION[] = "0.75 (18 April 2005)";
-static char *prog;
+#define ZCIP_VERSION "0.75 (18 April 2005)"
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.
*/
ip->s_addr = htonl((LINKLOCAL_ADDR + 0x0100) + tmp);
}
-/**
+/*
* Broadcast an ARP packet.
*/
static int
{
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;
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) {
- perror("sendto");
+ bb_perror_msg("sendto");
return -errno;
}
return 0;
}
-/**
+/*
* Run a script.
*/
static int
char *why;
if (script != NULL) {
- VDBG("%s run %s %s\n", intf, script, arg);
if (ip != NULL) {
char *addr = inet_ntoa(*ip);
- setenv("ip", addr, 1);
+ xsetenv("ip", addr);
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);
- perror("execl");
- _exit(EXIT_FAILURE);
+ bb_perror_msg_and_die("execl");
}
if (waitpid(pid, &status, 0) <= 0) {
goto bad;
}
if (WEXITSTATUS(status) != 0) {
- fprintf(stderr, "%s: script %s failed, exit=%d\n",
- prog, script, WEXITSTATUS(status));
+ bb_perror_msg("script %s failed, exit=%d", script, WEXITSTATUS(status));
return -errno;
}
}
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
return lrand48() % (secs * 1000);
}
-/**
+/*
* main program
*/
-int
-main(int argc, char *argv[])
- __attribute__ ((weak, alias ("zcip_main")));
+
+#define FOREGROUND 1
+#define QUIT 2
+#define REQUEST 4
+#define VERBOSE 8
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;
- 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");
- }
+ 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 (optind < argc - 1) {
- intf = argv[optind++];
- setenv("interface", intf, 1);
- script = argv[optind++];
+
+ if (t & VERBOSE) {
+ bb_printf("%s: version %s\n", bb_applet_name, ZCIP_VERSION);
}
- if (optind != argc || !intf)
- usage("wrong number of arguments");
- openlog(prog, 0, LOG_DAEMON);
-
- // initialize the interface (modprobe, ifup, etc)
+ 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");
+ }
+
+ 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 (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:
- foreground = 1;
+ t |= FOREGROUND;
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;
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) {
}
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 (!foreground) {
- if (daemon(0, verbose) < 0) {
+ /* daemonize now; don't delay system startup */
+ if (!(t & FOREGROUND)) {
+ if (daemon(0, (t & 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;
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;
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);
} 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 (quit)
+ /* NOTE: all other exit paths
+ should deconfig ... */
+ if (t & 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;
}
if ((fds[0].revents & POLLIN) == 0) {
if (fds[0].revents & POLLERR) {
- // FIXME: links routinely go down;
- // this shouldn't necessarily exit.
- fprintf(stderr, "%s %s: poll error\n",
- prog, intf);
+ /* FIXME: links routinely go down;
+ this shouldn't necessarily exit. */
+ bb_perror_msg("%s: poll error", 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);
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)
}
}
bad:
- if (foreground)
- perror(why);
- else
+ if ( t & FOREGROUND) {
+ bb_perror_msg(why);
+ } else {
syslog(LOG_ERR, "%s %s, %s error: %s",
- prog, intf, why, strerror(errno));
+ bb_applet_name, intf, why, strerror(errno));
+ }
return EXIT_FAILURE;
}
projects / platform / upstream / busybox.git / commitdiff