// - avoid silent script failures, especially under load...
// - link status monitoring (restart on link-up; stop on link-down)
-#include "busybox.h"
-#include <errno.h>
-#include <string.h>
+#include "libbb.h"
#include <syslog.h>
#include <poll.h>
-#include <time.h>
-
#include <sys/wait.h>
-
#include <netinet/ether.h>
#include <net/ethernet.h>
#include <net/if.h>
DEFEND
};
-#define DBG(fmt,args...) \
+#define VDBG(fmt,args...) \
do { } while (0)
-#define VDBG DBG
/**
* Pick a random link local IP address on 169.254/16, except that
*/
static void pick(struct in_addr *ip)
{
- unsigned tmp;
+ unsigned tmp;
/* use cheaper math than lrand48() mod N */
do {
ip->s_addr = htonl((LINKLOCAL_ADDR + 0x0100) + tmp);
}
+/* TODO: we need a flag to direct bb_[p]error_msg output to stderr. */
+
/**
* Broadcast an ARP packet.
*/
-static int arp(int fd, struct sockaddr *saddr, int op,
+static void arp(int fd, struct sockaddr *saddr, int op,
const struct ether_addr *source_addr, struct in_addr source_ip,
const struct ether_addr *target_addr, struct in_addr target_ip)
{
p.arp.arp_pln = 4;
p.arp.arp_op = htons(op);
memcpy(&p.arp.arp_sha, source_addr, ETH_ALEN);
- memcpy(&p.arp.arp_spa, &source_ip, sizeof (p.arp.arp_spa));
+ memcpy(&p.arp.arp_spa, &source_ip, sizeof(p.arp.arp_spa));
memcpy(&p.arp.arp_tha, target_addr, ETH_ALEN);
- memcpy(&p.arp.arp_tpa, &target_ip, sizeof (p.arp.arp_tpa));
+ memcpy(&p.arp.arp_tpa, &target_ip, sizeof(p.arp.arp_tpa));
// send it
- if (sendto(fd, &p, sizeof (p), 0, saddr, sizeof (*saddr)) < 0) {
- perror("sendto");
- return -errno;
- }
- return 0;
+ xsendto(fd, &p, sizeof(p), saddr, sizeof(*saddr));
+
+ // Currently all callers ignore errors, that's why returns are
+ // commented out...
+ //return 0;
}
/**
- * Run a script.
- * TODO: sort out stderr/syslog reporting.
+ * Run a script. argv[2] is already NULL.
*/
-static int run(char *script, char *arg, char *intf, struct in_addr *ip)
+static int run(char *argv[3], const char *intf, struct in_addr *ip)
{
- int pid, status;
- 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);
- syslog(LOG_INFO, "%s %s %s", arg, intf, addr);
- }
+ int status;
- pid = vfork();
- if (pid < 0) { // error
- why = "vfork";
- goto bad;
- } else if (pid == 0) { // child
- execl(script, script, arg, NULL);
- perror("execl");
- _exit(EXIT_FAILURE);
- }
+ VDBG("%s run %s %s\n", intf, argv[0], argv[1]);
- if (waitpid(pid, &status, 0) <= 0) {
- why = "waitpid";
- goto bad;
- }
- if (WEXITSTATUS(status) != 0) {
- bb_error_msg("script %s failed, exit=%d\n",
- script, WEXITSTATUS(status));
- return -errno;
- }
+ if (ip) {
+ char *addr = inet_ntoa(*ip);
+ setenv("ip", addr, 1);
+ bb_info_msg("%s %s %s", argv[1], intf, addr);
}
- return 0;
-bad:
- status = -errno;
- syslog(LOG_ERR, "%s %s, %s error: %s",
- arg, intf, why, strerror(errno));
+
+ status = wait4pid(spawn(argv));
+ if (status < 0) {
+ bb_perror_msg("%s %s", argv[1], intf);
+ return -errno;
+ }
+ if (status != 0)
+ bb_error_msg("script %s %s failed, exitcode=%d", argv[0], argv[1], status);
return status;
}
-
/**
* Return milliseconds of random delay, up to "secs" seconds.
*/
-static unsigned ATTRIBUTE_ALWAYS_INLINE ms_rdelay(unsigned secs)
+static unsigned ALWAYS_INLINE ms_rdelay(unsigned secs)
{
return lrand48() % (secs * 1000);
}
/**
* main program
*/
-
-/* Used to be auto variables on main() stack, but
- * most of them were zero-inited. Moving them to bss
- * is more space-efficient.
- */
-static const struct in_addr null_ip; // = { 0 };
-static const struct ether_addr null_addr; // = { {0, 0, 0, 0, 0, 0} };
-
-static struct sockaddr saddr; // memset(0);
-static struct in_addr ip; // = { 0 };
-static struct ifreq ifr; //memset(0);
-
-static char *intf; // = NULL;
-static char *script; // = NULL;
-static suseconds_t timeout; // = 0; // milliseconds
-static unsigned conflicts; // = 0;
-static unsigned nprobes; // = 0;
-static unsigned nclaims; // = 0;
-static int ready; // = 0;
-static int quit; // = 0;
-static int foreground; // = 0;
-static int verbose; // = 0;
-static int state = PROBE;
-
-int zcip_main(int argc, char *argv[])
+int zcip_main(int argc, char **argv);
+int zcip_main(int argc, char **argv)
{
+ int state = PROBE;
struct ether_addr eth_addr;
- char *why;
+ const char *why;
int fd;
- int t;
-
+ char *r_opt;
+ unsigned opts;
+
+ /* Ugly trick, but I want these zeroed in one go */
+ struct {
+ const struct in_addr null_ip;
+ const struct ether_addr null_addr;
+ struct sockaddr saddr;
+ struct in_addr ip;
+ struct ifreq ifr;
+ char *intf;
+ char *script_av[3];
+ suseconds_t timeout; // milliseconds
+ unsigned conflicts;
+ unsigned nprobes;
+ unsigned nclaims;
+ int ready;
+ int verbose;
+ } L;
+#define null_ip (L.null_ip )
+#define null_addr (L.null_addr)
+#define saddr (L.saddr )
+#define ip (L.ip )
+#define ifr (L.ifr )
+#define intf (L.intf )
+#define script_av (L.script_av)
+#define timeout (L.timeout )
+#define conflicts (L.conflicts)
+#define nprobes (L.nprobes )
+#define nclaims (L.nclaims )
+#define ready (L.ready )
+#define verbose (L.verbose )
+
+ memset(&L, 0, sizeof(L));
+
+#define FOREGROUND (opts & 1)
+#define QUIT (opts & 2)
// parse commandline: prog [options] ifname script
- 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) {
- bb_error_msg_and_die("invalid link address");
- }
- continue;
- case 'v':
- verbose++;
- foreground = 1;
- continue;
- default:
- bb_error_msg_and_die("bad option");
- }
+ // exactly 2 args; -v accumulates and implies -f
+ opt_complementary = "=2:vv:vf";
+ opts = getopt32(argc, argv, "fqr:v", &r_opt, &verbose);
+ if (!FOREGROUND) {
+ /* Do it early, before all bb_xx_msg calls */
+ openlog(applet_name, 0, LOG_DAEMON);
+ logmode |= LOGMODE_SYSLOG;
}
- if (optind < argc - 1) {
- intf = argv[optind++];
- setenv("interface", intf, 1);
- script = argv[optind++];
+ if (opts & 4) { // -r n.n.n.n
+ if (inet_aton(r_opt, &ip) == 0
+ || (ntohl(ip.s_addr) & IN_CLASSB_NET) != LINKLOCAL_ADDR
+ ) {
+ bb_error_msg_and_die("invalid link address");
+ }
}
- if (optind != argc || !intf)
- bb_show_usage();
- openlog(bb_applet_name, 0, LOG_DAEMON);
+ // On NOMMU reexec early (or else we will rerun things twice)
+#if !BB_MMU
+ if (!FOREGROUND)
+ bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
+#endif
+ argc -= optind;
+ argv += optind;
+
+ intf = argv[0];
+ script_av[0] = argv[1];
+ setenv("interface", intf, 1);
// initialize the interface (modprobe, ifup, etc)
- if (run(script, "init", intf, NULL) < 0)
+ script_av[1] = (char*)"init";
+ if (run(script_av, intf, NULL))
return EXIT_FAILURE;
// initialize saddr
- //memset(&saddr, 0, sizeof (saddr));
- safe_strncpy(saddr.sa_data, intf, sizeof (saddr.sa_data));
+ //memset(&saddr, 0, sizeof(saddr));
+ safe_strncpy(saddr.sa_data, intf, sizeof(saddr.sa_data));
// open an ARP socket
fd = xsocket(PF_PACKET, SOCK_PACKET, htons(ETH_P_ARP));
// bind to the interface's ARP socket
- xbind(fd, &saddr, sizeof (saddr);
+ xbind(fd, &saddr, sizeof(saddr));
// get the interface's ethernet address
- //memset(&ifr, 0, sizeof (ifr));
- strncpy(ifr.ifr_name, intf, sizeof (ifr.ifr_name));
+ //memset(&ifr, 0, sizeof(ifr));
+ strncpy(ifr.ifr_name, intf, sizeof(ifr.ifr_name));
if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) {
- foreground = 1;
- why = "get ethernet address";
- goto bad;
+ bb_perror_msg_and_die("get ethernet address");
}
memcpy(ð_addr, &ifr.ifr_hwaddr.sa_data, ETH_ALEN);
// - link already has local address... just defend/update
// daemonize now; don't delay system startup
- if (!foreground) {
- xdaemon(0, verbose);
- syslog(LOG_INFO, "start, interface %s", intf);
+ if (!FOREGROUND) {
+#if BB_MMU
+ bb_daemonize(DAEMON_CHDIR_ROOT);
+#endif
+ bb_info_msg("start, interface %s", intf);
}
// run the dynamic address negotiation protocol,
tv1.tv_sec++;
}
tv1.tv_sec += timeout / 1000;
-
+
VDBG("...wait %ld %s nprobes=%d, nclaims=%d\n",
timeout, intf, nprobes, nclaims);
switch (poll(fds, 1, timeout)) {
VDBG("state = %d\n", state);
switch (state) {
case PROBE:
- // timeouts in the PROBE state means no conflicting ARP packets
+ // timeouts in the PROBE state mean no conflicting ARP packets
// have been received, so we can progress through the states
if (nprobes < PROBE_NUM) {
nprobes++;
VDBG("probe/%d %s@%s\n",
nprobes, intf, inet_ntoa(ip));
- (void)arp(fd, &saddr, ARPOP_REQUEST,
+ arp(fd, &saddr, ARPOP_REQUEST,
ð_addr, null_ip,
&null_addr, ip);
timeout = PROBE_MIN * 1000;
nclaims = 0;
VDBG("announce/%d %s@%s\n",
nclaims, intf, inet_ntoa(ip));
- (void)arp(fd, &saddr, ARPOP_REQUEST,
+ arp(fd, &saddr, ARPOP_REQUEST,
ð_addr, ip,
ð_addr, ip);
timeout = ANNOUNCE_INTERVAL * 1000;
}
break;
case RATE_LIMIT_PROBE:
- // timeouts in the RATE_LIMIT_PROBE state means no conflicting ARP packets
+ // timeouts in the RATE_LIMIT_PROBE state mean no conflicting ARP packets
// have been received, so we can move immediately to the announce state
state = ANNOUNCE;
nclaims = 0;
VDBG("announce/%d %s@%s\n",
nclaims, intf, inet_ntoa(ip));
- (void)arp(fd, &saddr, ARPOP_REQUEST,
+ arp(fd, &saddr, ARPOP_REQUEST,
ð_addr, ip,
ð_addr, ip);
timeout = ANNOUNCE_INTERVAL * 1000;
break;
case ANNOUNCE:
- // timeouts in the ANNOUNCE state means no conflicting ARP packets
+ // timeouts in the ANNOUNCE state mean no conflicting ARP packets
// have been received, so we can progress through the states
if (nclaims < ANNOUNCE_NUM) {
nclaims++;
VDBG("announce/%d %s@%s\n",
nclaims, intf, inet_ntoa(ip));
- (void)arp(fd, &saddr, ARPOP_REQUEST,
+ arp(fd, &saddr, ARPOP_REQUEST,
ð_addr, ip,
ð_addr, ip);
timeout = ANNOUNCE_INTERVAL * 1000;
state = MONITOR;
// link is ok to use earlier
// FIXME update filters
- run(script, "config", intf, &ip);
+ script_av[1] = (char*)"config";
+ run(script_av, intf, &ip);
ready = 1;
conflicts = 0;
timeout = -1; // Never timeout in the monitor state.
- // NOTE: all other exit paths
+ // NOTE: all other exit paths
// should deconfig ...
- if (quit)
+ if (QUIT)
return EXIT_SUCCESS;
}
break;
if (fds[0].revents & POLLERR) {
// FIXME: links routinely go down;
// this shouldn't necessarily exit.
- bb_error_msg("%s: poll error\n", intf);
+ bb_error_msg("%s: poll error", intf);
if (ready) {
- run(script, "deconfig",
- intf, &ip);
+ script_av[1] = (char*)"deconfig";
+ run(script_av, intf, &ip);
}
return EXIT_FAILURE;
}
}
// read ARP packet
- if (recv(fd, &p, sizeof (p), 0) < 0) {
+ if (recv(fd, &p, sizeof(p), 0) < 0) {
why = "recv";
goto bad;
}
target_ip_conflict = 1;
}
- VDBG("state = %d, source ip conflict = %d, target ip conflict = %d\n",
+ VDBG("state = %d, source ip conflict = %d, target ip conflict = %d\n",
state, source_ip_conflict, target_ip_conflict);
switch (state) {
case PROBE:
VDBG("monitor conflict -- defending\n");
state = DEFEND;
timeout = DEFEND_INTERVAL * 1000;
- (void)arp(fd, &saddr,
+ arp(fd, &saddr,
ARPOP_REQUEST,
ð_addr, ip,
ð_addr, ip);
state = PROBE;
VDBG("defend conflict -- starting over\n");
ready = 0;
- run(script, "deconfig", intf, &ip);
+ script_av[1] = (char*)"deconfig";
+ run(script_av, intf, &ip);
// restart the whole protocol
pick(&ip);
goto bad;
} // switch poll
}
-bad:
- if (foreground)
- perror(why);
- else
- syslog(LOG_ERR, "%s %s, %s error: %s",
- bb_applet_name, intf, why, strerror(errno));
+ bad:
+ bb_perror_msg("%s, %s", intf, why);
return EXIT_FAILURE;
}
projects / oweals / busybox.git / blobdiff