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On Tuesday 19 April 2005 21:10, Tito wrote and today added:

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> 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....
This commit is contained in:
Rob Landley 2005-05-01 00:22:03 +00:00
parent 6624daeb4d
commit 8445a9ff99
3 changed files with 109 additions and 185 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
include/libbb.h
View File

@ -430,6 +430,7 @@ extern void run_shell ( const char *shell, int loginshell, const char *command,
); );
extern int run_parts(char **args, const unsigned char test_mode, char **env); extern int run_parts(char **args, const unsigned char test_mode, char **env);
extern int restricted_shell ( const char *shell ); extern int restricted_shell ( const char *shell );
extern void xsetenv ( const char *key, const char *value );
extern void setup_environment ( const char *shell, int loginshell, int changeenv, const struct passwd *pw ); extern void setup_environment ( const char *shell, int loginshell, int changeenv, const struct passwd *pw );
extern int correct_password ( const struct passwd *pw ); extern int correct_password ( const struct passwd *pw );
extern char *pw_encrypt(const char *clear, const char *salt); extern char *pw_encrypt(const char *clear, const char *salt);

2
libbb/setup_environment.c
View File

@ -42,7 +42,7 @@
#define DEFAULT_LOGIN_PATH "/bin:/usr/bin" #define DEFAULT_LOGIN_PATH "/bin:/usr/bin"
#define DEFAULT_ROOT_LOGIN_PATH "/usr/sbin:/bin:/usr/bin:/sbin" #define DEFAULT_ROOT_LOGIN_PATH "/usr/sbin:/bin:/usr/bin:/sbin"
static void xsetenv ( const char *key, const char *value ) void xsetenv ( const char *key, const char *value )
{ {
if ( setenv ( key, value, 1 )) if ( setenv ( key, value, 1 ))
bb_error_msg_and_die (bb_msg_memory_exhausted); bb_error_msg_and_die (bb_msg_memory_exhausted);

291
networking/zcip.c
View File

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