GOSIP Advanced Requirements Group, "Government Open Systems

20. GOSIP Advanced Requirements Group, "Government Open Systems

Interconnection Profile (GOSIP) Version 2.0 [Final Text]", Federal Information Processing Standard, U.S. Department of Commerce, National Institute of Standards and Technology, Gaithersburg, MD, October 1990.

21. "Standard for Local Area Networks and Metropolitan Area Networks: Overview and Architecture of Network Standards",IEEE Standard 802.1a-1990.

Додаток

#include "defs.h"

#include "pathnames.h"

#ifdef sgi

#include "math.h"

#endif

#include <signal.h>

#include <fcntl.h>

#include <sys/file.h>

pid_t mypid;

naddr myaddr; /* system address */

char myname[MAXHOSTNAMELEN+1];

int supplier; /* supply or broadcast updates */

int supplier_set;

int ipforwarding = 1; /* kernel forwarding on */

int default_gateway; /* 1=advertise default */

int background = 1;

int ridhosts; /* 1=reduce host routes */

int mhome; /* 1=want multi-homed host route */

int advertise_mhome; /* 1=must continue adverising it */

int auth_ok = 1; /* 1=ignore auth if we do not care */

struct timeval epoch; /* when started */

struct timeval clk, prev_clk;

struct timeval now; /* current idea of time */

time_t now_stale;

time_t now_expire;

time_t now_garbage;

struct timeval next_bcast; /* next general broadcast */

struct timeval no_flash = {EPOCH+SUPPLY_INTERVAL}; /* inhibit flash update */

fd_set fdbits;

int sock_max;

int rip_sock = -1; /* RIP socket */

struct interface *rip_sock_mcast; /* current multicast interface */

int rt_sock; /* routing socket */

int rt_sock_seqno;

static int get_rip_sock(naddr, int);

static void timevalsub(struct timeval *, struct timeval *, struct timeval *);

int

main(int argc,

char *argv[])

{

int n, mib[4], off;

size_t len;

char *p, *q;

struct timeval wtime, t2;

time_t dt;

fd_set ibits;

naddr p_net, p_mask;

struct interface *ifp;

struct parm parm;

char *tracename = 0;

/* Some shells are badly broken and send SIGHUP to backgrounded

* processes.

*/

signal(SIGHUP, SIG_IGN);

openlog("routed", LOG_PID | LOG_ODELAY, LOG_DAEMON);

ftrace = stdout;

gettimeofday(&clk, 0);

prev_clk = clk;

epoch = clk;

epoch.tv_sec -= EPOCH;

now.tv_sec = EPOCH;

now_stale = EPOCH - STALE_TIME;

now_expire = EPOCH - EXPIRE_TIME;

now_garbage = EPOCH - GARBAGE_TIME;

wtime.tv_sec = 0;

(void)gethostname(myname, sizeof(myname)-1);

(void)gethost(myname, &myaddr);

while ((n = getopt(argc, argv, "sqdghmAtT:F:P:")) != -1) {

switch (n) {

case 's':

supplier = 1;

supplier_set = 1;

break;

case 'q':

supplier = 0;

supplier_set = 1;

break;

case 'd':

background = 0;

break;

case 'g':

bzero(&parm, sizeof(parm));

parm.parm_d_metric = 1;

p = check_parms(&parm);

if (p != 0)

msglog("bad -g: %s", p);

else

default_gateway = 1;

break;

case 'h': /* suppress extra host routes */

ridhosts = 1;

break;

case 'm': /* advertise host route */

mhome = 1; /* on multi-homed hosts */

break;

case 'A':

/* Ignore authentication if we do not care.

* Crazy as it is, that is what RFC 1723 requires.

*/

auth_ok = 0;

break;

case 't':

new_tracelevel++;

break;

case 'T':

tracename = optarg;

break;

case 'F': /* minimal routes for SLIP */

n = FAKE_METRIC;

p = strchr(optarg,',');

if (p && *p != '\0') {

n = (int)strtoul(p+1, &q, 0);

if (*q == '\0'

&& n <= HOPCNT_INFINITY-1

&& n >= 1)

*p = '\0';

}

if (!getnet(optarg, &p_net, &p_mask)) {

msglog("bad network; \"-F %s\"",

optarg);

break;

}

bzero(&parm, sizeof(parm));

parm.parm_net = p_net;

parm.parm_mask = p_mask;

parm.parm_d_metric = n;

p = check_parms(&parm);

if (p != 0)

msglog("bad -F: %s", p);

break;

case 'P':

/* handle arbirary, (usually) per-interface

* parameters.

*/

p = parse_parms(optarg, 0);

if (p != 0) {

if (strcasecmp(p,optarg))

msglog("%s in \"%s\"", p, optarg);

else

msglog("bad \"-P %s\"", optarg);

}

break;

default:

goto usage;

}

}

argc -= optind;

argv += optind;

if (tracename == 0 && argc >= 1) {

tracename = *argv++;

argc--;

}

if (tracename != 0 && tracename[0] == '\0')

goto usage;

if (argc != 0) {

usage:

logbad(0, "usage: routed [-sqdghmAt] [-T tracefile]"

" [-F net[/mask[,metric]]] [-P parms]");

}

if (geteuid() != 0)

logbad(0, "requires UID 0");

mib[0] = CTL_NET;

mib[1] = PF_INET;

mib[2] = IPPROTO_IP;

mib[3] = IPCTL_FORWARDING;

len = sizeof(ipforwarding);

if (sysctl(mib, 4, &ipforwarding, &len, 0, 0) < 0)

LOGERR("sysctl(IPCTL_FORWARDING)");

if (!ipforwarding) {

if (supplier)

msglog("-s incompatible with ipforwarding=0");

if (default_gateway) {

msglog("-g incompatible with ipforwarding=0");

default_gateway = 0;

}

supplier = 0;

supplier_set = 1;

}

if (default_gateway) {

if (supplier_set && !supplier) {

msglog("-g and -q incompatible");

} else {

supplier = 1;

supplier_set = 1;

}

}

signal(SIGALRM, sigalrm);

if (!background)

signal(SIGHUP, sigterm); /* SIGHUP fatal during debugging */

signal(SIGTERM, sigterm);

signal(SIGINT, sigterm);

signal(SIGUSR1, sigtrace_on);

signal(SIGUSR2, sigtrace_off);

/* get into the background */

#ifdef sgi

if (0 > _daemonize(background ? 0 : (_DF_NOCHDIR|_DF_NOFORK),

new_tracelevel == 0 ? -1 : STDOUT_FILENO,

new_tracelevel == 0 ? -1 : STDERR_FILENO,

-1))

BADERR(0, "_daemonize()");

#else

if (background && daemon(0, new_tracelevel) < 0)

BADERR(0,"daemon()");

#endif

mypid = getpid();

srandom((int)(clk.tv_sec ^ clk.tv_usec ^ mypid));

/* prepare socket connected to the kernel.

*/

rt_sock = socket(AF_ROUTE, SOCK_RAW, 0);

if (rt_sock < 0)

BADERR(1,"rt_sock = socket()");

if (fcntl(rt_sock, F_SETFL, O_NONBLOCK) == -1)

logbad(1, "fcntl(rt_sock) O_NONBLOCK: %s", strerror(errno));

off = 0;

if (setsockopt(rt_sock, SOL_SOCKET,SO_USELOOPBACK,

&off,sizeof(off)) < 0)

LOGERR("setsockopt(SO_USELOOPBACK,0)");

fix_select();

if (background && new_tracelevel == 0)

ftrace = 0;

if (tracename != 0) {

strncpy(inittracename, tracename, sizeof(inittracename)-1);

set_tracefile(inittracename, "%s\n", -1);

} else {

tracelevel_msg("%s\n", -1); /* turn on tracing to stdio */

}

bufinit();

/* initialize radix tree */

rtinit();

/* Pick a random part of the second for our output to minimize

* collisions.

*

* Start broadcasting after hearing from other routers, and

* at a random time so a bunch of systems do not get synchronized

* after a power failure.

*/

intvl_random(&next_bcast, EPOCH+MIN_WAITTIME, EPOCH+SUPPLY_INTERVAL);

age_timer.tv_usec = next_bcast.tv_usec;

age_timer.tv_sec = EPOCH+MIN_WAITTIME;

rdisc_timer = next_bcast;

ifinit_timer.tv_usec = next_bcast.tv_usec;

/* Collect an initial view of the world by checking the interface

* configuration and the kludge file.

*/

gwkludge();

ifinit();

flush_kern();

/* Ask for routes */

rip_query();

rdisc_sol();

/* Loop forever, listening and broadcasting.

*/

for (;;) {

prev_clk = clk;

gettimeofday(&clk, 0);

timevalsub(&t2, &clk, &prev_clk);

if (t2.tv_sec < 0

|| t2.tv_sec > wtime.tv_sec + 5) {

/* Deal with time changes before other housekeeping to

* keep everything straight.

*/

dt = t2.tv_sec;

if (dt > 0)

dt -= wtime.tv_sec;

trace_act("time changed by %d sec", dt);

epoch.tv_sec += dt;

}

timevalsub(&now, &clk, &epoch);

now_stale = now.tv_sec - STALE_TIME;

now_expire = now.tv_sec - EXPIRE_TIME;

now_garbage = now.tv_sec - GARBAGE_TIME;

/* deal with signals that should affect tracing */

set_tracelevel();

if (stopint != 0) {

rip_bcast(0);

rdisc_adv();

trace_off("exiting with signal %d\n", stopint);

exit(stopint | 128);

}

/* look for new or dead interfaces */

timevalsub(&wtime, &ifinit_timer, &now);

if (wtime.tv_sec <= 0) {

wtime.tv_sec = 0;

ifinit();

rip_query();

continue;

}

/* If it is time, then broadcast our routes.

*/

if (supplier || advertise_mhome) {

timevalsub(&t2, &next_bcast, &now);

if (t2.tv_sec <= 0) {

/* Synchronize the aging and broadcast

* timers to minimize awakenings

*/

age(0);

rip_bcast(0);

/* It is desirable to send routing updates

* regularly. So schedule the next update

* 30 seconds after the previous one was

* secheduled, instead of 30 seconds after

* the previous update was finished.

* Even if we just started after discovering

* a 2nd interface or were otherwise delayed,

* pick a 30-second aniversary of the

* original broadcast time.

*/

n = 1 + (0-t2.tv_sec)/SUPPLY_INTERVAL;

next_bcast.tv_sec += n*SUPPLY_INTERVAL;

continue;

}

if (timercmp(&t2, &wtime, <))

wtime = t2;

}

/* If we need a flash update, either do it now or

* set the delay to end when it is time.

*

* If we are within MIN_WAITTIME seconds of a full update,

* do not bother.

*/

if (need_flash

&& supplier

&& no_flash.tv_sec+MIN_WAITTIME < next_bcast.tv_sec) {

/* accurate to the millisecond */

if (!timercmp(&no_flash, &now, >))

rip_bcast(1);

timevalsub(&t2, &no_flash, &now);

if (timercmp(&t2, &wtime, <))

wtime = t2;

}

/* trigger the main aging timer.

*/

timevalsub(&t2, &age_timer, &now);

if (t2.tv_sec <= 0) {

age(0);

continue;

}

if (timercmp(&t2, &wtime, <))

wtime = t2;

/* update the kernel routing table

*/

timevalsub(&t2, &need_kern, &now);

if (t2.tv_sec <= 0) {

age(0);

continue;

}

if (timercmp(&t2, &wtime, <))

wtime = t2;

/* take care of router discovery,

* but do it to the millisecond

*/

if (!timercmp(&rdisc_timer, &now, >)) {

rdisc_age(0);

continue;

}

timevalsub(&t2, &rdisc_timer, &now);

if (timercmp(&t2, &wtime, <))

wtime = t2;

/* wait for input or a timer to expire.

*/

trace_flush();

ibits = fdbits;

n = select(sock_max, &ibits, 0, 0, &wtime);

if (n <= 0) {

if (n < 0 && errno != EINTR && errno != EAGAIN)

BADERR(1,"select");

continue;

}

if (FD_ISSET(rt_sock, &ibits)) {

read_rt();

n--;

}

if (rdisc_sock >= 0 && FD_ISSET(rdisc_sock, &ibits)) {

read_d();

n--;

}

if (rip_sock >= 0 && FD_ISSET(rip_sock, &ibits)) {

read_rip(rip_sock, 0);

n--;

}

for (ifp = ifnet; n > 0 && 0 != ifp; ifp = ifp->int_next) {

if (ifp->int_rip_sock >= 0

&& FD_ISSET(ifp->int_rip_sock, &ibits)) {

read_rip(ifp->int_rip_sock, ifp);

n--;

}

}

}

}

/* ARGSUSED */

void

sigalrm(int s)

{

/* Historically, SIGALRM would cause the daemon to check for

* new and broken interfaces.

*/

ifinit_timer.tv_sec = now.tv_sec;

trace_act("SIGALRM");

}

/* watch for fatal signals */

void

sigterm(int sig)

{

stopint = sig;

(void)signal(sig, SIG_DFL); /* catch it only once */

}

void

fix_select(void)

{

struct interface *ifp;

FD_ZERO(&fdbits);

sock_max = 0;

FD_SET(rt_sock, &fdbits);

if (sock_max <= rt_sock)

sock_max = rt_sock+1;

if (rip_sock >= 0) {

FD_SET(rip_sock, &fdbits);

if (sock_max <= rip_sock)

sock_max = rip_sock+1;

}

for (ifp = ifnet; 0 != ifp; ifp = ifp->int_next) {

if (ifp->int_rip_sock >= 0) {

FD_SET(ifp->int_rip_sock, &fdbits);

if (sock_max <= ifp->int_rip_sock)

sock_max = ifp->int_rip_sock+1;

}

}

if (rdisc_sock >= 0) {

FD_SET(rdisc_sock, &fdbits);

if (sock_max <= rdisc_sock)

sock_max = rdisc_sock+1;

}

}

void

fix_sock(int sock,

char *name)

{

int on;

#define MIN_SOCKBUF (4*1024)

static int rbuf;

if (fcntl(sock, F_SETFL, O_NONBLOCK) == -1)

logbad(1, "fcntl(%s) O_NONBLOCK: %s",

name, strerror(errno));

on = 1;

if (setsockopt(sock, SOL_SOCKET,SO_BROADCAST, &on,sizeof(on)) < 0)

msglog("setsockopt(%s,SO_BROADCAST): %s",

name, strerror(errno));

#ifdef USE_PASSIFNAME

on = 1;

if (setsockopt(sock, SOL_SOCKET, SO_PASSIFNAME, &on,sizeof(on)) < 0)

msglog("setsockopt(%s,SO_PASSIFNAME): %s",

name, strerror(errno));

#endif

if (rbuf >= MIN_SOCKBUF) {

if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,

&rbuf, sizeof(rbuf)) < 0)

msglog("setsockopt(%s,SO_RCVBUF=%d): %s",

name, rbuf, strerror(errno));

} else {

for (rbuf = 60*1024; ; rbuf -= 4096) {

if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,

&rbuf, sizeof(rbuf)) == 0) {

trace_act("RCVBUF=%d", rbuf);

break;

}

if (rbuf < MIN_SOCKBUF) {

msglog("setsockopt(%s,SO_RCVBUF = %d): %s",

name, rbuf, strerror(errno));

break;

}

}

}

}

/* get a rip socket

*/

static int /* <0 or file descriptor */

get_rip_sock(naddr addr,

int serious) /* 1=failure to bind is serious */

{

struct sockaddr_in sin;

unsigned char ttl;

int s;

if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)

BADERR(1,"rip_sock = socket()");

bzero(&sin,sizeof(sin));

#ifdef _HAVE_SIN_LEN

sin.sin_len = sizeof(sin);

#endif

sin.sin_family = AF_INET;

sin.sin_port = htons(RIP_PORT);

sin.sin_addr.s_addr = addr;

if (bind(s, (struct sockaddr *)&sin,sizeof(sin)) < 0) {

if (serious)

BADERR(errno != EADDRINUSE, "bind(rip_sock)");

return -1;

}

fix_sock(s,"rip_sock");

ttl = 1;

if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL,

&ttl, sizeof(ttl)) < 0)

DBGERR(1,"rip_sock setsockopt(IP_MULTICAST_TTL)");

return s;

}

/* turn off main RIP socket */

void

rip_off(void)

{

struct interface *ifp;

register naddr addr;

if (rip_sock >= 0 && !mhome) {

trace_act("turn off RIP");

(void)close(rip_sock);

rip_sock = -1;

/* get non-broadcast sockets to listen to queries.

*/

for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {

if (ifp->int_state & IS_REMOTE)

continue;

if (ifp->int_rip_sock < 0) {

addr = ((ifp->int_if_flags & IFF_POINTOPOINT)

? ifp->int_dstaddr

: ifp->int_addr);

ifp->int_rip_sock = get_rip_sock(addr, 0);

}

}

fix_select();

age(0);

}

}

/* turn on RIP multicast input via an interface

*/

static void

rip_mcast_on(struct interface *ifp)

{

struct ip_mreq m;

if (!IS_RIP_IN_OFF(ifp->int_state)

&& (ifp->int_if_flags & IFF_MULTICAST)

#ifdef MCAST_PPP_BUG

&& !(ifp->int_if_flags & IFF_POINTOPOINT)

#endif

&& !(ifp->int_state & IS_ALIAS)) {

m.imr_multiaddr.s_addr = htonl(INADDR_RIP_GROUP);

m.imr_interface.s_addr = ((ifp->int_if_flags & IFF_POINTOPOINT)

? ifp->int_dstaddr

: ifp->int_addr);

if (setsockopt(rip_sock,IPPROTO_IP, IP_ADD_MEMBERSHIP,

&m, sizeof(m)) < 0)

LOGERR("setsockopt(IP_ADD_MEMBERSHIP RIP)");

}

}

/* Prepare socket used for RIP.

*/

void

rip_on(struct interface *ifp)

{

/* If the main RIP socket is already alive, only start receiving

* multicasts for this interface.

*/

if (rip_sock >= 0) {

if (ifp != 0)

rip_mcast_on(ifp);

return;

}

/* If the main RIP socket is off and it makes sense to turn it on,

* then turn it on for all of the interfaces.

*/

if (rip_interfaces > 0 && !rdisc_ok) {

trace_act("turn on RIP");

/* Close all of the query sockets so that we can open

* the main socket. SO_REUSEPORT is not a solution,

* since that would let two daemons bind to the broadcast

* socket.

*/

for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {

if (ifp->int_rip_sock >= 0) {

(void)close(ifp->int_rip_sock);

ifp->int_rip_sock = -1;

}

}

rip_sock = get_rip_sock(INADDR_ANY, 1);

rip_sock_mcast = 0;

/* Do not advertise anything until we have heard something

*/

if (next_bcast.tv_sec < now.tv_sec+MIN_WAITTIME)

next_bcast.tv_sec = now.tv_sec+MIN_WAITTIME;

for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {

ifp->int_query_time = NEVER;

rip_mcast_on(ifp);

}

ifinit_timer.tv_sec = now.tv_sec;

} else if (ifp != 0

&& !(ifp->int_state & IS_REMOTE)

&& ifp->int_rip_sock < 0) {

/* RIP is off, so ensure there are sockets on which

* to listen for queries.

*/

ifp->int_rip_sock = get_rip_sock(ifp->int_addr, 0);

}

fix_select();

}

/* die if malloc(3) fails

*/

void *

rtmalloc(size_t size,

char *msg)

{

void *p = malloc(size);

if (p == 0)

logbad(1,"malloc() failed in %s", msg);

return p;

}

/* get a random instant in an interval

*/

void

intvl_random(struct timeval *tp, /* put value here */

u_long lo, /* value is after this second */

u_long hi) /* and before this */

{

tp->tv_sec = (time_t)(hi == lo

? lo

: (lo + random() % ((hi - lo))));

tp->tv_usec = random() % 1000000;

}

void

timevaladd(struct timeval *t1,

struct timeval *t2)

{

t1->tv_sec += t2->tv_sec;

if ((t1->tv_usec += t2->tv_usec) > 1000000) {

t1->tv_sec++;

t1->tv_usec -= 1000000;

}

}

/* t1 = t2 - t3

*/

static void

timevalsub(struct timeval *t1,

struct timeval *t2,

struct timeval *t3)

{

t1->tv_sec = t2->tv_sec - t3->tv_sec;

if ((t1->tv_usec = t2->tv_usec - t3->tv_usec) < 0) {

t1->tv_sec--;

t1->tv_usec += 1000000;

}

}

/* put a message into the system log

*/

void

msglog(char *p, ...)

{

va_list args;

trace_flush();

va_start(args, p);

vsyslog(LOG_ERR, p, args);

if (ftrace != 0) {

if (ftrace == stdout)

(void)fputs("routed: ", ftrace);

(void)vfprintf(ftrace, p, args);

(void)fputc('\n', ftrace);

}

}

/* Put a message about a bad system into the system log if

* we have not complained about it recently.

*

* It is desirable to complain about all bad systems, but not too often.

* In the worst case, it is not practical to keep track of all bad systems.

* For example, there can be many systems with the wrong password.

*/

void

msglim(struct msg_limit *lim, naddr addr, char *p, ...)

{

va_list args;

int i;

struct msg_sub *ms1, *ms;

char *p1;

va_start(args, p);

/* look for the oldest slot in the table

* or the slot for the bad router.

*/

ms = ms1 = lim->subs;

for (i = MSG_SUBJECT_N; ; i--, ms1++) {

if (i == 0) {

/* Reuse a slot at most once every 10 minutes.

*/

if (lim->reuse > now.tv_sec) {

ms = 0;

} else {

ms = ms1;

lim->reuse = now.tv_sec + 10*60;

}

break;

}

if (ms->addr == addr) {

/* Repeat a complaint about a given system at

* most once an hour.

*/

if (ms->until > now.tv_sec)

ms = 0;

break;

}

if (ms->until < ms1->until)

ms = ms1;

}

if (ms != 0) {

ms->addr = addr;

ms->until = now.tv_sec + 60*60; /* 60 minutes */

trace_flush();

for (p1 = p; *p1 == ' '; p1++)

continue;

vsyslog(LOG_ERR, p1, args);

}

/* always display the message if tracing */

if (ftrace != 0) {

(void)vfprintf(ftrace, p, args);

(void)fputc('\n', ftrace);

}

}

void

logbad(int dump, char *p, ...)

{

va_list args;

trace_flush();

va_start(args, p);

vsyslog(LOG_ERR, p, args);

(void)fputs("routed: ", stderr);

(void)vfprintf(stderr, p, args);

(void)fputs("; giving up\n",stderr);

(void)fflush(stderr);

if (dump)

abort();

exit(1);

}

Список литературы

Для подготовки данной работы были использованы материалы с сайта http://www.referaty.com.ua/