diff options
author | Rob Landley <rob@landley.net> | 2005-05-01 04:22:03 +0400 |
---|---|---|
committer | Rob Landley <rob@landley.net> | 2005-05-01 04:22:03 +0400 |
commit | 8445a9ff99f04cad8845a1aed6ab17737f2d985a (patch) | |
tree | f31c09bf14817ee84ae6fbc247f0c62152fff7e7 /networking | |
parent | 6624daeb4d040a39ad7d6b66ff11339c710d0f3d (diff) |
On Tuesday 19 April 2005 21:10, Tito wrote and today added:
> Hi,
> this is a first attempt of size optimization for zcip taking into account all
> the hints given so far on the list.
> I've applied just the more obvious busyboxifications so maybe it could be
> optimized more.
BTW: I've ripped out a lot of debug code and changed c++ // comments to /* */
as both were rather confusing for a newbie like me. ;-)
Sorry to the author for that.
I know that this makes mantaining the code easier, but I'm simple minded....
Diffstat (limited to 'networking')
-rw-r--r-- | networking/zcip.c | 295 |
1 files changed, 109 insertions, 186 deletions
diff --git a/networking/zcip.c b/networking/zcip.c index ccf399bb7..de9ea7675 100644 --- a/networking/zcip.c +++ b/networking/zcip.c @@ -31,14 +31,12 @@ * 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> @@ -63,11 +61,12 @@ #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; @@ -90,29 +89,13 @@ static const unsigned ANNOUNCE_NUM = 2; 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. */ @@ -128,7 +111,7 @@ pick(struct in_addr *ip) ip->s_addr = htonl((LINKLOCAL_ADDR + 0x0100) + tmp); } -/** +/* * Broadcast an ARP packet. */ static int @@ -138,12 +121,12 @@ 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; @@ -154,15 +137,15 @@ 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) { - perror("sendto"); + bb_perror_msg("sendto"); return -errno; } return 0; } -/** +/* * Run a script. */ static int @@ -172,21 +155,19 @@ 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); - 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) { @@ -194,8 +175,7 @@ run(char *script, char *arg, char *intf, struct in_addr *ip) 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; } } @@ -207,31 +187,7 @@ 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 @@ -240,85 +196,72 @@ ms_rdelay(unsigned secs) 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; @@ -326,7 +269,7 @@ 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) { @@ -335,37 +278,37 @@ 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 (!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; @@ -375,7 +318,7 @@ 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; @@ -386,21 +329,17 @@ 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); @@ -411,38 +350,36 @@ 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 (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; @@ -454,46 +391,33 @@ fail: } 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); @@ -504,28 +428,26 @@ 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) @@ -541,10 +463,11 @@ collision: } } 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; } |