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- #include <u.h>
- #include <libc.h>
- #include <ip.h>
- #include <pool.h>
- #include <ctype.h>
- #include "dns.h"
- /*
- * this comment used to say `our target is 4000 names cached, this should
- * be larger on large servers'. dns at Bell Labs starts off with
- * about 1780 names.
- *
- * aging seems to corrupt the cache, so raise the trigger from 4000 until we
- * figure it out.
- */
- enum {
- Deftarget = 1<<30, /* effectively disable aging */
- Minage = 1<<30,
- Defagefreq = 1<<30, /* age names this often (seconds) */
- Restartmins = 600,
- /* these settings will trigger frequent aging */
- // Deftarget = 4000,
- // Minage = 5*60,
- // Defagefreq = 15*60, /* age names this often (seconds) */
- };
- /*
- * Hash table for domain names. The hash is based only on the
- * first element of the domain name.
- */
- DN *ht[HTLEN];
- static struct {
- Lock;
- ulong names; /* names allocated */
- ulong oldest; /* longest we'll leave a name around */
- int active;
- int mutex;
- ushort id; /* same size as in packet */
- } dnvars;
- /* names of RR types */
- char *rrtname[] =
- {
- [Ta] "ip",
- [Tns] "ns",
- [Tmd] "md",
- [Tmf] "mf",
- [Tcname] "cname",
- [Tsoa] "soa",
- [Tmb] "mb",
- [Tmg] "mg",
- [Tmr] "mr",
- [Tnull] "null",
- [Twks] "wks",
- [Tptr] "ptr",
- [Thinfo] "hinfo",
- [Tminfo] "minfo",
- [Tmx] "mx",
- [Ttxt] "txt",
- [Trp] "rp",
- [Tafsdb] "afsdb",
- [Tx25] "x.25",
- [Tisdn] "isdn",
- [Trt] "rt",
- [Tnsap] "nsap",
- [Tnsapptr] "nsap-ptr",
- [Tsig] "sig",
- [Tkey] "key",
- [Tpx] "px",
- [Tgpos] "gpos",
- [Taaaa] "ipv6",
- [Tloc] "loc",
- [Tnxt] "nxt",
- [Teid] "eid",
- [Tnimloc] "nimrod",
- [Tsrv] "srv",
- [Tatma] "atma",
- [Tnaptr] "naptr",
- [Tkx] "kx",
- [Tcert] "cert",
- [Ta6] "a6",
- [Tdname] "dname",
- [Tsink] "sink",
- [Topt] "opt",
- [Tapl] "apl",
- [Tds] "ds",
- [Tsshfp] "sshfp",
- [Tipseckey] "ipseckey",
- [Trrsig] "rrsig",
- [Tnsec] "nsec",
- [Tdnskey] "dnskey",
- [Tspf] "spf",
- [Tuinfo] "uinfo",
- [Tuid] "uid",
- [Tgid] "gid",
- [Tunspec] "unspec",
- [Ttkey] "tkey",
- [Ttsig] "tsig",
- [Tixfr] "ixfr",
- [Taxfr] "axfr",
- [Tmailb] "mailb",
- [Tmaila] "maila",
- [Tall] "all",
- 0,
- };
- /* names of response codes */
- char *rname[Rmask+1] =
- {
- [Rok] "ok",
- [Rformat] "format error",
- [Rserver] "server failure",
- [Rname] "bad name",
- [Runimplimented] "unimplemented",
- [Rrefused] "we don't like you",
- [Ryxdomain] "name should not exist",
- [Ryxrrset] "rr set should not exist",
- [Rnxrrset] "rr set should exist",
- [Rnotauth] "not authorative",
- [Rnotzone] "not in zone",
- [Rbadvers] "bad opt version",
- /* [Rbadsig] "bad signature", */
- [Rbadkey] "bad key",
- [Rbadtime] "bad signature time",
- [Rbadmode] "bad mode",
- [Rbadname] "duplicate key name",
- [Rbadalg] "bad algorithm",
- };
- unsigned nrname = nelem(rname);
- /* names of op codes */
- char *opname[] =
- {
- [Oquery] "query",
- [Oinverse] "inverse query (retired)",
- [Ostatus] "status",
- [Oupdate] "update",
- };
- ulong target = Deftarget;
- ulong start;
- Lock dnlock;
- static ulong agefreq = Defagefreq;
- static int rrequiv(RR *r1, RR *r2);
- static int sencodefmt(Fmt*);
- static void
- ding(void*, char *msg)
- {
- if(strstr(msg, "alarm") != nil) {
- stats.alarms++;
- noted(NCONT); /* resume with system call error */
- } else
- noted(NDFLT); /* die */
- }
- void
- dninit(void)
- {
- fmtinstall('E', eipfmt);
- fmtinstall('I', eipfmt);
- fmtinstall('V', eipfmt);
- fmtinstall('R', rrfmt);
- fmtinstall('Q', rravfmt);
- fmtinstall('H', sencodefmt);
- dnvars.oldest = maxage;
- dnvars.names = 0;
- dnvars.id = truerand(); /* don't start with same id every time */
- notify(ding);
- }
- /*
- * hash for a domain name
- */
- static ulong
- dnhash(char *name)
- {
- ulong hash;
- uchar *val = (uchar*)name;
- for(hash = 0; *val; val++)
- hash = hash*13 + tolower(*val)-'a';
- return hash % HTLEN;
- }
- /*
- * lookup a symbol. if enter is not zero and the name is
- * not found, create it.
- */
- DN*
- dnlookup(char *name, int class, int enter)
- {
- DN **l;
- DN *dp;
- l = &ht[dnhash(name)];
- lock(&dnlock);
- for(dp = *l; dp; dp = dp->next) {
- assert(dp->magic == DNmagic);
- if(dp->class == class && cistrcmp(dp->name, name) == 0){
- dp->referenced = now;
- unlock(&dnlock);
- return dp;
- }
- l = &dp->next;
- }
- if(!enter){
- unlock(&dnlock);
- return 0;
- }
- dnvars.names++;
- dp = emalloc(sizeof(*dp));
- dp->magic = DNmagic;
- dp->name = estrdup(name);
- assert(dp->name != nil);
- dp->class = class;
- dp->rr = 0;
- dp->referenced = now;
- /* add new DN to tail of the hash list. *l points to last next ptr. */
- dp->next = nil;
- *l = dp;
- unlock(&dnlock);
- return dp;
- }
- static int
- rrsame(RR *rr1, RR *rr2)
- {
- return rr1 == rr2 || rr2 && rrequiv(rr1, rr2) &&
- rr1->db == rr2->db && rr1->auth == rr2->auth;
- }
- static int
- rronlist(RR *rp, RR *lp)
- {
- for(; lp; lp = lp->next)
- if (rrsame(lp, rp))
- return 1;
- return 0;
- }
- /*
- * dump the stats
- */
- void
- dnstats(char *file)
- {
- int i, fd;
- fd = create(file, OWRITE, 0666);
- if(fd < 0)
- return;
- qlock(&stats);
- fprint(fd, "# system %s\n", sysname());
- fprint(fd, "# slave procs high-water mark\t%lud\n", stats.slavehiwat);
- fprint(fd, "# queries received by 9p\t%lud\n", stats.qrecvd9p);
- fprint(fd, "# queries received by udp\t%lud\n", stats.qrecvdudp);
- fprint(fd, "# queries answered from memory\t%lud\n", stats.answinmem);
- fprint(fd, "# queries sent by udp\t%lud\n", stats.qsent);
- for (i = 0; i < nelem(stats.under10ths); i++)
- if (stats.under10ths[i] || i == nelem(stats.under10ths) - 1)
- fprint(fd, "# responses arriving within %.1f s.\t%lud\n",
- (double)(i+1)/10, stats.under10ths[i]);
- fprint(fd, "\n# queries sent & timed-out\t%lud\n", stats.tmout);
- fprint(fd, "# cname queries timed-out\t%lud\n", stats.tmoutcname);
- fprint(fd, "# ipv6 queries timed-out\t%lud\n", stats.tmoutv6);
- fprint(fd, "\n# negative answers received\t%lud\n", stats.negans);
- fprint(fd, "# negative answers w Rserver set\t%lud\n", stats.negserver);
- fprint(fd, "# negative answers w bad delegation\t%lud\n",
- stats.negbaddeleg);
- fprint(fd, "# negative answers w bad delegation & no answers\t%lud\n",
- stats.negbdnoans);
- fprint(fd, "# negative answers w no Rname set\t%lud\n", stats.negnorname);
- fprint(fd, "# negative answers cached\t%lud\n", stats.negcached);
- qunlock(&stats);
- lock(&dnlock);
- fprint(fd, "\n# domain names %lud target %lud\n", dnvars.names, target);
- unlock(&dnlock);
- close(fd);
- }
- /*
- * dump the cache
- */
- void
- dndump(char *file)
- {
- int i, fd;
- DN *dp;
- RR *rp;
- fd = create(file, OWRITE, 0666);
- if(fd < 0)
- return;
- lock(&dnlock);
- for(i = 0; i < HTLEN; i++)
- for(dp = ht[i]; dp; dp = dp->next){
- fprint(fd, "%s\n", dp->name);
- for(rp = dp->rr; rp; rp = rp->next) {
- fprint(fd, "\t%R %c%c %lud/%lud\n",
- rp, rp->auth? 'A': 'U',
- rp->db? 'D': 'N', rp->expire, rp->ttl);
- if (rronlist(rp, rp->next))
- fprint(fd, "*** duplicate:\n");
- }
- }
- unlock(&dnlock);
- close(fd);
- }
- /*
- * purge all records
- */
- void
- dnpurge(void)
- {
- DN *dp;
- RR *rp, *srp;
- int i;
- lock(&dnlock);
- for(i = 0; i < HTLEN; i++)
- for(dp = ht[i]; dp; dp = dp->next){
- srp = rp = dp->rr;
- dp->rr = nil;
- for(; rp != nil; rp = rp->next)
- rp->cached = 0;
- rrfreelist(srp);
- }
- unlock(&dnlock);
- }
- /*
- * delete head of *l and free the old head.
- * call with dnlock held.
- */
- static void
- rrdelhead(RR **l)
- {
- RR *rp;
- if (canlock(&dnlock))
- abort(); /* rrdelhead called with dnlock not held */
- rp = *l;
- if(rp == nil)
- return;
- *l = rp->next; /* unlink head */
- rp->cached = 0; /* avoid blowing an assertion in rrfree */
- rrfree(rp);
- }
- /*
- * check the age of resource records, free any that have timed out.
- * call with dnlock held.
- */
- void
- dnage(DN *dp)
- {
- RR **l;
- RR *rp, *next;
- ulong diff;
- if (canlock(&dnlock))
- abort(); /* dnage called with dnlock not held */
- diff = now - dp->referenced;
- if(diff < Reserved || dp->keep)
- return;
- l = &dp->rr;
- for(rp = dp->rr; rp; rp = next){
- assert(rp->magic == RRmagic && rp->cached);
- next = rp->next;
- if(!rp->db && (rp->expire < now || diff > dnvars.oldest))
- rrdelhead(l); /* rp == *l before; *l == rp->next after */
- else
- l = &rp->next;
- }
- }
- #define MARK(dp) { if (dp) (dp)->keep = 1; }
- /* mark a domain name and those in its RRs as never to be aged */
- void
- dnagenever(DN *dp, int dolock)
- {
- RR *rp;
- if (dolock)
- lock(&dnlock);
- /* mark all referenced domain names */
- MARK(dp);
- for(rp = dp->rr; rp; rp = rp->next){
- MARK(rp->owner);
- if(rp->negative){
- MARK(rp->negsoaowner);
- continue;
- }
- switch(rp->type){
- case Thinfo:
- MARK(rp->cpu);
- MARK(rp->os);
- break;
- case Ttxt:
- break;
- case Tcname:
- case Tmb:
- case Tmd:
- case Tmf:
- case Tns:
- case Tmx:
- case Tsrv:
- MARK(rp->host);
- break;
- case Tmg:
- case Tmr:
- MARK(rp->mb);
- break;
- case Tminfo:
- MARK(rp->rmb);
- MARK(rp->mb);
- break;
- case Trp:
- MARK(rp->rmb);
- MARK(rp->rp);
- break;
- case Ta:
- case Taaaa:
- MARK(rp->ip);
- break;
- case Tptr:
- MARK(rp->ptr);
- break;
- case Tsoa:
- MARK(rp->host);
- MARK(rp->rmb);
- break;
- }
- }
- if (dolock)
- unlock(&dnlock);
- }
- /* mark all current domain names as never to be aged */
- void
- dnageallnever(void)
- {
- int i;
- DN *dp;
- lock(&dnlock);
- /* mark all referenced domain names */
- for(i = 0; i < HTLEN; i++)
- for(dp = ht[i]; dp; dp = dp->next)
- dnagenever(dp, 0);
- unlock(&dnlock);
- dnslog("%ld initial domain names; target is %ld", dnvars.names, target);
- if(dnvars.names >= target)
- dnslog("more initial domain names (%ld) than target (%ld)",
- dnvars.names, target);
- }
- #define REF(dp) { if (dp) (dp)->refs++; }
- /*
- * periodicly sweep for old records and remove unreferenced domain names
- *
- * only called when all other threads are locked out
- */
- void
- dnageall(int doit)
- {
- DN *dp, **l;
- int i;
- RR *rp;
- static ulong nextage;
- if(dnvars.names < target || (now < nextage && !doit)){
- dnvars.oldest = maxage;
- return;
- }
- if(dnvars.names >= target) {
- dnslog("more names (%lud) than target (%lud)", dnvars.names,
- target);
- dnvars.oldest /= 2;
- if (dnvars.oldest < Minage)
- dnvars.oldest = Minage; /* don't be silly */
- }
- if (agefreq > dnvars.oldest / 2)
- nextage = now + dnvars.oldest / 2;
- else
- nextage = now + agefreq;
- lock(&dnlock);
- /* time out all old entries (and set refs to 0) */
- for(i = 0; i < HTLEN; i++)
- for(dp = ht[i]; dp; dp = dp->next){
- dp->refs = 0;
- dnage(dp);
- }
- /* mark all referenced domain names */
- for(i = 0; i < HTLEN; i++)
- for(dp = ht[i]; dp; dp = dp->next)
- for(rp = dp->rr; rp; rp = rp->next){
- REF(rp->owner);
- if(rp->negative){
- REF(rp->negsoaowner);
- continue;
- }
- switch(rp->type){
- case Thinfo:
- REF(rp->cpu);
- REF(rp->os);
- break;
- case Ttxt:
- break;
- case Tcname:
- case Tmb:
- case Tmd:
- case Tmf:
- case Tns:
- case Tmx:
- case Tsrv:
- REF(rp->host);
- break;
- case Tmg:
- case Tmr:
- REF(rp->mb);
- break;
- case Tminfo:
- REF(rp->rmb);
- REF(rp->mb);
- break;
- case Trp:
- REF(rp->rmb);
- REF(rp->rp);
- break;
- case Ta:
- case Taaaa:
- REF(rp->ip);
- break;
- case Tptr:
- REF(rp->ptr);
- break;
- case Tsoa:
- REF(rp->host);
- REF(rp->rmb);
- break;
- }
- }
- /* sweep and remove unreferenced domain names */
- for(i = 0; i < HTLEN; i++){
- l = &ht[i];
- for(dp = *l; dp; dp = *l){
- if(dp->rr == 0 && dp->refs == 0 && !dp->keep){
- assert(dp->magic == DNmagic);
- *l = dp->next;
- if(dp->name)
- free(dp->name);
- dp->magic = ~dp->magic;
- dnvars.names--;
- memset(dp, 0, sizeof *dp); /* cause trouble */
- free(dp);
- continue;
- }
- l = &dp->next;
- }
- }
- unlock(&dnlock);
- }
- /*
- * timeout all database records (used when rereading db)
- */
- void
- dnagedb(void)
- {
- DN *dp;
- int i;
- RR *rp;
- lock(&dnlock);
- /* time out all database entries */
- for(i = 0; i < HTLEN; i++)
- for(dp = ht[i]; dp; dp = dp->next) {
- dp->keep = 0;
- for(rp = dp->rr; rp; rp = rp->next)
- if(rp->db)
- rp->expire = 0;
- }
- unlock(&dnlock);
- }
- /*
- * mark all local db records about my area as authoritative,
- * time out any others
- */
- void
- dnauthdb(void)
- {
- int i;
- ulong minttl;
- Area *area;
- DN *dp;
- RR *rp;
- lock(&dnlock);
- /* time out all database entries */
- for(i = 0; i < HTLEN; i++)
- for(dp = ht[i]; dp; dp = dp->next){
- area = inmyarea(dp->name);
- for(rp = dp->rr; rp; rp = rp->next)
- if(rp->db){
- if(area){
- minttl = area->soarr->soa->minttl;
- if(rp->ttl < minttl)
- rp->ttl = minttl;
- rp->auth = 1;
- }
- if(rp->expire == 0){
- rp->db = 0;
- dp->referenced = now-Reserved-1;
- }
- }
- }
- unlock(&dnlock);
- }
- /*
- * keep track of other processes to know if we can
- * garbage collect. block while garbage collecting.
- */
- int
- getactivity(Request *req, int recursive)
- {
- int rv;
- if(traceactivity)
- dnslog("get: %d active by pid %d from %p",
- dnvars.active, getpid(), getcallerpc(&req));
- lock(&dnvars);
- /*
- * can't block here if we're already holding one
- * of the dnvars.active (recursive). will deadlock.
- */
- while(!recursive && dnvars.mutex){
- unlock(&dnvars);
- sleep(100); /* tune; was 200 */
- lock(&dnvars);
- }
- rv = ++dnvars.active;
- now = time(nil);
- nowns = nsec();
- req->id = ++dnvars.id;
- unlock(&dnvars);
- return rv;
- }
- void
- putactivity(int recursive)
- {
- static ulong lastclean;
- if(traceactivity)
- dnslog("put: %d active by pid %d",
- dnvars.active, getpid());
- lock(&dnvars);
- dnvars.active--;
- assert(dnvars.active >= 0); /* "dnvars.active %d", dnvars.active */
- /*
- * clean out old entries and check for new db periodicly
- * can't block here if being called to let go a "recursive" lock
- * or we'll deadlock waiting for ourselves to give up the dnvars.active.
- */
- if (recursive || dnvars.mutex ||
- (needrefresh == 0 && dnvars.active > 0)){
- unlock(&dnvars);
- return;
- }
- /* wait till we're alone */
- dnvars.mutex = 1;
- while(dnvars.active > 0){
- unlock(&dnvars);
- sleep(100); /* tune; was 100 */
- lock(&dnvars);
- }
- unlock(&dnvars);
- db2cache(needrefresh);
- /* if we've been running for long enough, restart */
- if(start == 0)
- start = time(nil);
- if(0 && time(nil) - start > Restartmins*60){ // TODO
- dnslog("killing all dns procs for timed restart");
- postnote(PNGROUP, getpid(), "die");
- dnvars.mutex = 0;
- exits("restart");
- }
- dnageall(0);
- /* let others back in */
- lastclean = now;
- needrefresh = 0;
- dnvars.mutex = 0;
- }
- int
- rrlistlen(RR *rp)
- {
- int n;
- n = 0;
- for(; rp; rp = rp->next)
- ++n;
- return n;
- }
- /*
- * Attach a single resource record to a domain name (new->owner).
- * - Avoid duplicates with already present RR's
- * - Chain all RR's of the same type adjacent to one another
- * - chain authoritative RR's ahead of non-authoritative ones
- * - remove any expired RR's
- * If new is a stale duplicate, rrfree it.
- * Must be called with dnlock held.
- */
- static void
- rrattach1(RR *new, int auth)
- {
- RR **l;
- RR *rp;
- DN *dp;
- assert(new->magic == RRmagic && !new->cached);
- // dnslog("rrattach1: %s", new->owner->name);
- if(!new->db) {
- /*
- * try not to let responses expire before we
- * can use them to complete this query, by extending
- * past (or nearly past) expiration time.
- */
- new->expire = new->ttl > now + Min? new->ttl: now + 10*Min;
- } else
- new->expire = now + Year;
- dp = new->owner;
- assert(dp->magic == DNmagic);
- new->auth |= auth;
- new->next = 0;
- /*
- * find first rr of the right type
- */
- l = &dp->rr;
- for(rp = *l; rp; rp = *l){
- assert(rp->magic == RRmagic && rp->cached);
- if(rp->type == new->type)
- break;
- l = &rp->next;
- }
- /*
- * negative entries replace positive entries
- * positive entries replace negative entries
- * newer entries replace older entries with the same fields
- *
- * look farther ahead than just the next entry when looking
- * for duplicates; RRs of a given type can have different rdata
- * fields (e.g. multiple NS servers).
- */
- while ((rp = *l) != nil){
- assert(rp->magic == RRmagic && rp->cached);
- if(rp->type != new->type)
- break;
- if(rp->db == new->db && rp->auth == new->auth){
- /* negative drives out positive and vice versa */
- if(rp->negative != new->negative) {
- /* rp == *l before; *l == rp->next after */
- rrdelhead(l);
- continue;
- }
- /* all things equal, pick the newer one */
- else if(rp->arg0 == new->arg0 && rp->arg1 == new->arg1){
- /* new drives out old */
- if (new->ttl <= rp->ttl &&
- new->expire <= rp->expire) {
- rrfree(new);
- return;
- }
- /* rp == *l before; *l == rp->next after */
- rrdelhead(l);
- continue;
- }
- /*
- * Hack for pointer records. This makes sure
- * the ordering in the list reflects the ordering
- * received or read from the database
- */
- else if(rp->type == Tptr &&
- !rp->negative && !new->negative &&
- rp->ptr->ordinal > new->ptr->ordinal)
- break;
- }
- l = &rp->next;
- }
- if (rronlist(new, rp)) {
- /* should not happen; duplicates were processed above */
- dnslog("adding duplicate %R to list of %R; aborting", new, rp);
- abort();
- }
- /*
- * add to chain
- */
- new->cached = 1;
- new->next = rp;
- *l = new;
- }
- /*
- * Attach a list of resource records to a domain name.
- * May rrfree any stale duplicate RRs; dismembers the list.
- * Upon return, every RR in the list will have been rrfree-d
- * or attached to its domain name.
- * See rrattach1 for properties preserved.
- */
- void
- rrattach(RR *rp, int auth)
- {
- RR *next, *tp;
- DN *dp;
- lock(&dnlock);
- for(; rp; rp = next){
- next = rp->next;
- rp->next = nil;
- dp = rp->owner;
- // dnslog("rrattach: %s", rp->owner->name);
- /* avoid any outside spoofing; leave keepers alone */
- if(cfg.cachedb && !rp->db && inmyarea(rp->owner->name)
- // || dp->keep /* TODO: make this work */
- )
- rrfree(rp);
- else {
- /* ameliorate the memory leak (someday delete this) */
- if (0 && rrlistlen(dp->rr) > 50 && !dp->keep) {
- dnslog("rrattach(%s): rr list too long; "
- "freeing it", dp->name);
- tp = dp->rr;
- dp->rr = nil;
- rrfreelist(tp);
- } else
- USED(dp);
- rrattach1(rp, auth);
- }
- }
- unlock(&dnlock);
- }
- /* should be called with dnlock held */
- RR**
- rrcopy(RR *rp, RR **last)
- {
- Cert *cert;
- Key *key;
- Null *null;
- RR *nrp;
- SOA *soa;
- Sig *sig;
- Txt *t, *nt, **l;
- if (canlock(&dnlock))
- abort(); /* rrcopy called with dnlock not held */
- nrp = rralloc(rp->type);
- setmalloctag(nrp, getcallerpc(&rp));
- switch(rp->type){
- case Ttxt:
- *nrp = *rp;
- l = &nrp->txt;
- *l = nil;
- for(t = rp->txt; t != nil; t = t->next){
- nt = emalloc(sizeof(*nt));
- nt->p = estrdup(t->p);
- nt->next = nil;
- *l = nt;
- l = &nt->next;
- }
- break;
- case Tsoa:
- soa = nrp->soa;
- *nrp = *rp;
- nrp->soa = soa;
- *nrp->soa = *rp->soa;
- nrp->soa->slaves = copyserverlist(rp->soa->slaves);
- break;
- case Tsrv:
- *nrp = *rp;
- nrp->srv = emalloc(sizeof *nrp->srv);
- *nrp->srv = *rp->srv;
- break;
- case Tkey:
- key = nrp->key;
- *nrp = *rp;
- nrp->key = key;
- *key = *rp->key;
- key->data = emalloc(key->dlen);
- memmove(key->data, rp->key->data, rp->key->dlen);
- break;
- case Tsig:
- sig = nrp->sig;
- *nrp = *rp;
- nrp->sig = sig;
- *sig = *rp->sig;
- sig->data = emalloc(sig->dlen);
- memmove(sig->data, rp->sig->data, rp->sig->dlen);
- break;
- case Tcert:
- cert = nrp->cert;
- *nrp = *rp;
- nrp->cert = cert;
- *cert = *rp->cert;
- cert->data = emalloc(cert->dlen);
- memmove(cert->data, rp->cert->data, rp->cert->dlen);
- break;
- case Tnull:
- null = nrp->null;
- *nrp = *rp;
- nrp->null = null;
- *null = *rp->null;
- null->data = emalloc(null->dlen);
- memmove(null->data, rp->null->data, rp->null->dlen);
- break;
- default:
- *nrp = *rp;
- break;
- }
- nrp->cached = 0;
- nrp->next = 0;
- *last = nrp;
- return &nrp->next;
- }
- /*
- * lookup a resource record of a particular type and
- * class attached to a domain name. Return copies.
- *
- * Priority ordering is:
- * db authoritative
- * not timed out network authoritative
- * not timed out network unauthoritative
- * unauthoritative db
- *
- * if flag NOneg is set, don't return negative cached entries.
- * return nothing instead.
- */
- RR*
- rrlookup(DN *dp, int type, int flag)
- {
- RR *rp, *first, **last;
- assert(dp->magic == DNmagic);
- first = 0;
- last = &first;
- lock(&dnlock);
- /* try for an authoritative db entry */
- for(rp = dp->rr; rp; rp = rp->next){
- assert(rp->magic == RRmagic && rp->cached);
- if(rp->db)
- if(rp->auth)
- if(tsame(type, rp->type)) {
- last = rrcopy(rp, last);
- // setmalloctag(*last, getcallerpc(&dp));
- }
- }
- if(first)
- goto out;
- /* try for a living authoritative network entry */
- for(rp = dp->rr; rp; rp = rp->next){
- if(!rp->db)
- if(rp->auth)
- if(rp->ttl + 60 > now)
- if(tsame(type, rp->type)){
- if(flag == NOneg && rp->negative)
- goto out;
- last = rrcopy(rp, last);
- }
- }
- if(first)
- goto out;
- /* try for a living unauthoritative network entry */
- for(rp = dp->rr; rp; rp = rp->next){
- if(!rp->db)
- if(rp->ttl + 60 > now)
- if(tsame(type, rp->type)){
- if(flag == NOneg && rp->negative)
- goto out;
- last = rrcopy(rp, last);
- }
- }
- if(first)
- goto out;
- /* try for an unauthoritative db entry */
- for(rp = dp->rr; rp; rp = rp->next){
- if(rp->db)
- if(tsame(type, rp->type))
- last = rrcopy(rp, last);
- }
- if(first)
- goto out;
- /* otherwise, settle for anything we got (except for negative caches) */
- for(rp = dp->rr; rp; rp = rp->next)
- if(tsame(type, rp->type)){
- if(rp->negative)
- goto out;
- last = rrcopy(rp, last);
- }
- out:
- unique(first);
- unlock(&dnlock);
- // dnslog("rrlookup(%s) -> %#p\t# in-core only", dp->name, first);
- // if (first)
- // setmalloctag(first, getcallerpc(&dp));
- return first;
- }
- /*
- * convert an ascii RR type name to its integer representation
- */
- int
- rrtype(char *atype)
- {
- int i;
- for(i = 0; i <= Tall; i++)
- if(rrtname[i] && strcmp(rrtname[i], atype) == 0)
- return i;
- /* make any a synonym for all */
- if(strcmp(atype, "any") == 0)
- return Tall;
- else if(isascii(atype[0]) && isdigit(atype[0]))
- return atoi(atype);
- else
- return -1;
- }
- /*
- * return 0 if not a supported rr type
- */
- int
- rrsupported(int type)
- {
- if(type < 0 || type >Tall)
- return 0;
- return rrtname[type] != nil;
- }
- /*
- * compare 2 types
- */
- int
- tsame(int t1, int t2)
- {
- return t1 == t2 || t1 == Tall;
- }
- /*
- * Add resource records to a list, duplicate them if they are cached
- * RR's since these are shared. should be called with dnlock held
- * to avoid racing down the start chain.
- */
- RR*
- rrcat(RR **start, RR *rp)
- {
- RR *olp, *nlp;
- RR **last;
- if (canlock(&dnlock))
- abort(); /* rrcat called with dnlock not held */
- /* check for duplicates */
- for (olp = *start; 0 && olp; olp = olp->next)
- for (nlp = rp; nlp; nlp = nlp->next)
- if (rrsame(nlp, olp))
- dnslog("rrcat: duplicate RR: %R", nlp);
- USED(olp);
- last = start;
- while(*last != nil)
- last = &(*last)->next;
- *last = rp;
- return *start;
- }
- /*
- * remove negative cache rr's from an rr list
- */
- RR*
- rrremneg(RR **l)
- {
- RR **nl, *rp;
- RR *first;
- if (canlock(&dnlock))
- abort(); /* rrremneg called with dnlock not held */
- first = nil;
- nl = &first;
- while(*l != nil){
- rp = *l;
- if(rp->negative){
- *l = rp->next;
- *nl = rp;
- nl = &rp->next;
- *nl = nil;
- } else
- l = &rp->next;
- }
- return first;
- }
- /*
- * remove rr's of a particular type from an rr list
- */
- RR*
- rrremtype(RR **l, int type)
- {
- RR *first, *rp;
- RR **nl;
- first = nil;
- nl = &first;
- while(*l != nil){
- rp = *l;
- if(rp->type == type){
- *l = rp->next;
- *nl = rp;
- nl = &rp->next;
- *nl = nil;
- } else
- l = &(*l)->next;
- }
- return first;
- }
- static char *
- dnname(DN *dn)
- {
- return dn? dn->name: "<null>";
- }
- /*
- * print conversion for rr records
- */
- int
- rrfmt(Fmt *f)
- {
- int rv;
- char *strp;
- char buf[Domlen];
- Fmt fstr;
- RR *rp;
- Server *s;
- SOA *soa;
- Srv *srv;
- Txt *t;
- fmtstrinit(&fstr);
- rp = va_arg(f->args, RR*);
- if(rp == nil){
- fmtprint(&fstr, "<null>");
- goto out;
- }
- fmtprint(&fstr, "%s %s", dnname(rp->owner),
- rrname(rp->type, buf, sizeof buf));
- if(rp->negative){
- fmtprint(&fstr, "\tnegative - rcode %d", rp->negrcode);
- goto out;
- }
- switch(rp->type){
- case Thinfo:
- fmtprint(&fstr, "\t%s %s", dnname(rp->cpu), dnname(rp->os));
- break;
- case Tcname:
- case Tmb:
- case Tmd:
- case Tmf:
- case Tns:
- fmtprint(&fstr, "\t%s", dnname(rp->host));
- break;
- case Tmg:
- case Tmr:
- fmtprint(&fstr, "\t%s", dnname(rp->mb));
- break;
- case Tminfo:
- fmtprint(&fstr, "\t%s %s", dnname(rp->mb), dnname(rp->rmb));
- break;
- case Tmx:
- fmtprint(&fstr, "\t%lud %s", rp->pref, dnname(rp->host));
- break;
- case Ta:
- case Taaaa:
- fmtprint(&fstr, "\t%s", dnname(rp->ip));
- break;
- case Tptr:
- // fmtprint(&fstr, "\t%s(%lud)", dnname(rp->ptr),
- // rp->ptr? rp->ptr->ordinal: "<null>");
- fmtprint(&fstr, "\t%s", dnname(rp->ptr));
- break;
- case Tsoa:
- soa = rp->soa;
- fmtprint(&fstr, "\t%s %s %lud %lud %lud %lud %lud",
- dnname(rp->host), dnname(rp->rmb),
- (soa? soa->serial: 0),
- (soa? soa->refresh: 0), (soa? soa->retry: 0),
- (soa? soa->expire: 0), (soa? soa->minttl: 0));
- if (soa)
- for(s = soa->slaves; s != nil; s = s->next)
- fmtprint(&fstr, " %s", s->name);
- break;
- case Tsrv:
- srv = rp->srv;
- fmtprint(&fstr, "\t%ud %ud %ud %s",
- (srv? srv->pri: 0), (srv? srv->weight: 0),
- rp->port, dnname(rp->host));
- break;
- case Tnull:
- if (rp->null == nil)
- fmtprint(&fstr, "\t<null>");
- else
- fmtprint(&fstr, "\t%.*H", rp->null->dlen,
- rp->null->data);
- break;
- case Ttxt:
- fmtprint(&fstr, "\t");
- for(t = rp->txt; t != nil; t = t->next)
- fmtprint(&fstr, "%s", t->p);
- break;
- case Trp:
- fmtprint(&fstr, "\t%s %s", dnname(rp->rmb), dnname(rp->rp));
- break;
- case Tkey:
- if (rp->key == nil)
- fmtprint(&fstr, "\t<null> <null> <null>");
- else
- fmtprint(&fstr, "\t%d %d %d", rp->key->flags,
- rp->key->proto, rp->key->alg);
- break;
- case Tsig:
- if (rp->sig == nil)
- fmtprint(&fstr,
- "\t<null> <null> <null> <null> <null> <null> <null> <null>");
- else
- fmtprint(&fstr, "\t%d %d %d %lud %lud %lud %d %s",
- rp->sig->type, rp->sig->alg, rp->sig->labels,
- rp->sig->ttl, rp->sig->exp, rp->sig->incep,
- rp->sig->tag, dnname(rp->sig->signer));
- break;
- case Tcert:
- if (rp->cert == nil)
- fmtprint(&fstr, "\t<null> <null> <null>");
- else
- fmtprint(&fstr, "\t%d %d %d",
- rp->cert->type, rp->cert->tag, rp->cert->alg);
- break;
- }
- out:
- strp = fmtstrflush(&fstr);
- rv = fmtstrcpy(f, strp);
- free(strp);
- return rv;
- }
- /*
- * print conversion for rr records in attribute value form
- */
- int
- rravfmt(Fmt *f)
- {
- int rv, quote;
- char *strp;
- Fmt fstr;
- RR *rp;
- Server *s;
- SOA *soa;
- Srv *srv;
- Txt *t;
- fmtstrinit(&fstr);
- rp = va_arg(f->args, RR*);
- if(rp == nil){
- fmtprint(&fstr, "<null>");
- goto out;
- }
- if(rp->type == Tptr)
- fmtprint(&fstr, "ptr=%s", dnname(rp->owner));
- else
- fmtprint(&fstr, "dom=%s", dnname(rp->owner));
- switch(rp->type){
- case Thinfo:
- fmtprint(&fstr, " cpu=%s os=%s",
- dnname(rp->cpu), dnname(rp->os));
- break;
- case Tcname:
- fmtprint(&fstr, " cname=%s", dnname(rp->host));
- break;
- case Tmb:
- case Tmd:
- case Tmf:
- fmtprint(&fstr, " mbox=%s", dnname(rp->host));
- break;
- case Tns:
- fmtprint(&fstr, " ns=%s", dnname(rp->host));
- break;
- case Tmg:
- case Tmr:
- fmtprint(&fstr, " mbox=%s", dnname(rp->mb));
- break;
- case Tminfo:
- fmtprint(&fstr, " mbox=%s mbox=%s",
- dnname(rp->mb), dnname(rp->rmb));
- break;
- case Tmx:
- fmtprint(&fstr, " pref=%lud mx=%s", rp->pref, dnname(rp->host));
- break;
- case Ta:
- case Taaaa:
- fmtprint(&fstr, " ip=%s", dnname(rp->ip));
- break;
- case Tptr:
- fmtprint(&fstr, " dom=%s", dnname(rp->ptr));
- break;
- case Tsoa:
- soa = rp->soa;
- fmtprint(&fstr,
- " ns=%s mbox=%s serial=%lud refresh=%lud retry=%lud expire=%lud ttl=%lud",
- dnname(rp->host), dnname(rp->rmb),
- (soa? soa->serial: 0),
- (soa? soa->refresh: 0), (soa? soa->retry: 0),
- (soa? soa->expire: 0), (soa? soa->minttl: 0));
- for(s = soa->slaves; s != nil; s = s->next)
- fmtprint(&fstr, " dnsslave=%s", s->name);
- break;
- case Tsrv:
- srv = rp->srv;
- fmtprint(&fstr, " pri=%ud weight=%ud port=%ud target=%s",
- (srv? srv->pri: 0), (srv? srv->weight: 0),
- rp->port, dnname(rp->host));
- break;
- case Tnull:
- if (rp->null == nil)
- fmtprint(&fstr, " null=<null>");
- else
- fmtprint(&fstr, " null=%.*H", rp->null->dlen,
- rp->null->data);
- break;
- case Ttxt:
- fmtprint(&fstr, " txt=");
- quote = 0;
- for(t = rp->txt; t != nil; t = t->next)
- if(strchr(t->p, ' '))
- quote = 1;
- if(quote)
- fmtprint(&fstr, "\"");
- for(t = rp->txt; t != nil; t = t->next)
- fmtprint(&fstr, "%s", t->p);
- if(quote)
- fmtprint(&fstr, "\"");
- break;
- case Trp:
- fmtprint(&fstr, " rp=%s txt=%s",
- dnname(rp->rmb), dnname(rp->rp));
- break;
- case Tkey:
- if (rp->key == nil)
- fmtprint(&fstr, " flags=<null> proto=<null> alg=<null>");
- else
- fmtprint(&fstr, " flags=%d proto=%d alg=%d",
- rp->key->flags, rp->key->proto, rp->key->alg);
- break;
- case Tsig:
- if (rp->sig == nil)
- fmtprint(&fstr,
- " type=<null> alg=<null> labels=<null> ttl=<null> exp=<null> incep=<null> tag=<null> signer=<null>");
- else
- fmtprint(&fstr,
- " type=%d alg=%d labels=%d ttl=%lud exp=%lud incep=%lud tag=%d signer=%s",
- rp->sig->type, rp->sig->alg, rp->sig->labels,
- rp->sig->ttl, rp->sig->exp, rp->sig->incep,
- rp->sig->tag, dnname(rp->sig->signer));
- break;
- case Tcert:
- if (rp->cert == nil)
- fmtprint(&fstr, " type=<null> tag=<null> alg=<null>");
- else
- fmtprint(&fstr, " type=%d tag=%d alg=%d",
- rp->cert->type, rp->cert->tag, rp->cert->alg);
- break;
- }
- out:
- strp = fmtstrflush(&fstr);
- rv = fmtstrcpy(f, strp);
- free(strp);
- return rv;
- }
- void
- warning(char *fmt, ...)
- {
- char dnserr[256];
- va_list arg;
- va_start(arg, fmt);
- vseprint(dnserr, dnserr+sizeof(dnserr), fmt, arg);
- va_end(arg);
- syslog(1, logfile, dnserr); /* on console too */
- }
- void
- dnslog(char *fmt, ...)
- {
- char dnserr[256];
- va_list arg;
- va_start(arg, fmt);
- vseprint(dnserr, dnserr+sizeof(dnserr), fmt, arg);
- va_end(arg);
- syslog(0, logfile, dnserr);
- }
- /*
- * based on libthread's threadsetname, but drags in less library code.
- * actually just sets the arguments displayed.
- */
- void
- procsetname(char *fmt, ...)
- {
- int fd;
- char *cmdname;
- char buf[128];
- va_list arg;
- va_start(arg, fmt);
- cmdname = vsmprint(fmt, arg);
- va_end(arg);
- if (cmdname == nil)
- return;
- snprint(buf, sizeof buf, "#p/%d/args", getpid());
- if((fd = open(buf, OWRITE)) >= 0){
- write(fd, cmdname, strlen(cmdname)+1);
- close(fd);
- }
- free(cmdname);
- }
- /*
- * create a slave process to handle a request to avoid one request blocking
- * another
- */
- void
- slave(Request *req)
- {
- int ppid, procs;
- if(req->isslave)
- return; /* we're already a slave process */
- /*
- * These calls to putactivity cannot block.
- * After getactivity(), the current process is counted
- * twice in dnvars.active (one will pass to the child).
- * If putactivity tries to wait for dnvars.active == 0,
- * it will never happen.
- */
- /* limit parallelism */
- procs = getactivity(req, 1);
- if (procs > stats.slavehiwat)
- stats.slavehiwat = procs;
- if(procs > Maxactive){
- if(traceactivity)
- dnslog("[%d] too much activity", getpid());
- putactivity(1);
- return;
- }
- /*
- * parent returns to main loop, child does the work.
- * don't change note group.
- */
- ppid = getpid();
- switch(rfork(RFPROC|RFMEM|RFNOWAIT)){
- case -1:
- putactivity(1);
- break;
- case 0:
- procsetname("request slave of pid %d", ppid);
- if(traceactivity)
- dnslog("[%d] take activity from %d", getpid(), ppid);
- req->isslave = 1; /* why not `= getpid()'? */
- break;
- default:
- /*
- * this relies on rfork producing separate, initially-identical
- * stacks, thus giving us two copies of `req', one in each
- * process.
- */
- alarm(0);
- longjmp(req->mret, 1);
- }
- }
- /*
- * chasing down double free's
- */
- void
- dncheck(void *p, int dolock)
- {
- int i;
- DN *dp;
- RR *rp;
- if(p != nil){
- dp = p;
- assert(dp->magic == DNmagic);
- }
- if(!testing)
- return;
- if(dolock)
- lock(&dnlock);
- poolcheck(mainmem);
- for(i = 0; i < HTLEN; i++)
- for(dp = ht[i]; dp; dp = dp->next){
- assert(dp != p);
- assert(dp->magic == DNmagic);
- for(rp = dp->rr; rp; rp = rp->next){
- assert(rp->magic == RRmagic);
- assert(rp->cached);
- assert(rp->owner == dp);
- /* also check for duplicate rrs */
- if (dolock && rronlist(rp, rp->next)) {
- dnslog("%R duplicates its next chain "
- "(%R); aborting", rp, rp->next);
- abort();
- }
- }
- }
- if(dolock)
- unlock(&dnlock);
- }
- static int
- rrequiv(RR *r1, RR *r2)
- {
- return r1->owner == r2->owner
- && r1->type == r2->type
- && r1->arg0 == r2->arg0
- && r1->arg1 == r2->arg1;
- }
- /* called with dnlock held */
- void
- unique(RR *rp)
- {
- RR **l, *nrp;
- for(; rp; rp = rp->next){
- l = &rp->next;
- for(nrp = *l; nrp; nrp = *l)
- if(rrequiv(rp, nrp)){
- *l = nrp->next;
- rrfree(nrp);
- } else
- l = &nrp->next;
- }
- }
- /*
- * true if second domain is subsumed by the first
- */
- int
- subsume(char *higher, char *lower)
- {
- int hn, ln;
- ln = strlen(lower);
- hn = strlen(higher);
- if (ln < hn || cistrcmp(lower + ln - hn, higher) != 0 ||
- ln > hn && hn != 0 && lower[ln - hn - 1] != '.')
- return 0;
- return 1;
- }
- /*
- * randomize the order we return items to provide some
- * load balancing for servers.
- *
- * only randomize the first class of entries
- */
- RR*
- randomize(RR *rp)
- {
- RR *first, *last, *x, *base;
- ulong n;
- if(rp == nil || rp->next == nil)
- return rp;
- /* just randomize addresses, mx's and ns's */
- for(x = rp; x; x = x->next)
- if(x->type != Ta && x->type != Taaaa &&
- x->type != Tmx && x->type != Tns)
- return rp;
- base = rp;
- n = rand();
- last = first = nil;
- while(rp != nil){
- /* stop randomizing if we've moved past our class */
- if(base->auth != rp->auth || base->db != rp->db){
- last->next = rp;
- break;
- }
- /* unchain */
- x = rp;
- rp = x->next;
- x->next = nil;
- if(n&1){
- /* add to tail */
- if(last == nil)
- first = x;
- else
- last->next = x;
- last = x;
- } else {
- /* add to head */
- if(last == nil)
- last = x;
- x->next = first;
- first = x;
- }
- /* reroll the dice */
- n >>= 1;
- }
- return first;
- }
- static int
- sencodefmt(Fmt *f)
- {
- int i, len, ilen, rv;
- char *out, *buf;
- uchar *b;
- char obuf[64]; /* rsc optimization */
- if(!(f->flags&FmtPrec) || f->prec < 1)
- goto error;
- b = va_arg(f->args, uchar*);
- if(b == nil)
- goto error;
- /* if it's a printable, go for it */
- len = f->prec;
- for(i = 0; i < len; i++)
- if(!isprint(b[i]))
- break;
- if(i == len){
- if(len >= sizeof obuf)
- len = sizeof(obuf)-1;
- memmove(obuf, b, len);
- obuf[len] = 0;
- fmtstrcpy(f, obuf);
- return 0;
- }
- ilen = f->prec;
- f->prec = 0;
- f->flags &= ~FmtPrec;
- switch(f->r){
- case '<':
- len = (8*ilen+4)/5 + 3;
- break;
- case '[':
- len = (8*ilen+5)/6 + 4;
- break;
- case 'H':
- len = 2*ilen + 1;
- break;
- default:
- goto error;
- }
- if(len > sizeof(obuf)){
- buf = malloc(len);
- if(buf == nil)
- goto error;
- } else
- buf = obuf;
- /* convert */
- out = buf;
- switch(f->r){
- case '<':
- rv = enc32(out, len, b, ilen);
- break;
- case '[':
- rv = enc64(out, len, b, ilen);
- break;
- case 'H':
- rv = enc16(out, len, b, ilen);
- break;
- default:
- rv = -1;
- break;
- }
- if(rv < 0)
- goto error;
- fmtstrcpy(f, buf);
- if(buf != obuf)
- free(buf);
- return 0;
- error:
- return fmtstrcpy(f, "<encodefmt>");
- }
- void*
- emalloc(int size)
- {
- char *x;
- x = mallocz(size, 1);
- if(x == nil)
- abort();
- setmalloctag(x, getcallerpc(&size));
- return x;
- }
- char*
- estrdup(char *s)
- {
- int size;
- char *p;
- size = strlen(s)+1;
- p = mallocz(size, 0);
- if(p == nil)
- abort();
- memmove(p, s, size);
- setmalloctag(p, getcallerpc(&s));
- return p;
- }
- /*
- * create a pointer record
- */
- static RR*
- mkptr(DN *dp, char *ptr, ulong ttl)
- {
- DN *ipdp;
- RR *rp;
- ipdp = dnlookup(ptr, Cin, 1);
- rp = rralloc(Tptr);
- rp->ptr = dp;
- rp->owner = ipdp;
- rp->db = 1;
- if(ttl)
- rp->ttl = ttl;
- return rp;
- }
- void bytes2nibbles(uchar *nibbles, uchar *bytes, int nbytes);
- /*
- * look for all ip addresses in this network and make
- * pointer records for them.
- */
- void
- dnptr(uchar *net, uchar *mask, char *dom, int forwtype, int subdoms, int ttl)
- {
- int i, j, len;
- char *p, *e;
- char ptr[Domlen];
- uchar *ipp;
- uchar ip[IPaddrlen], nnet[IPaddrlen];
- uchar nibip[IPaddrlen*2];
- DN *dp;
- RR *rp, *nrp, *first, **l;
- l = &first;
- first = nil;
- for(i = 0; i < HTLEN; i++)
- for(dp = ht[i]; dp; dp = dp->next)
- for(rp = dp->rr; rp; rp = rp->next){
- if(rp->type != forwtype || rp->negative)
- continue;
- parseip(ip, rp->ip->name);
- maskip(ip, mask, nnet);
- if(ipcmp(net, nnet) != 0)
- continue;
- ipp = ip;
- len = IPaddrlen;
- if (forwtype == Taaaa) {
- bytes2nibbles(nibip, ip, IPaddrlen);
- ipp = nibip;
- len = 2*IPaddrlen;
- }
- p = ptr;
- e = ptr+sizeof(ptr);
- for(j = len - 1; j >= len - subdoms; j--)
- p = seprint(p, e, (forwtype == Ta?
- "%d.": "%x."), ipp[j]);
- seprint(p, e, "%s", dom);
- nrp = mkptr(dp, ptr, ttl);
- *l = nrp;
- l = &nrp->next;
- }
- for(rp = first; rp != nil; rp = nrp){
- nrp = rp->next;
- rp->next = nil;
- rrattach(rp, Authoritative);
- }
- }
- void
- addserver(Server **l, char *name)
- {
- Server *s;
- while(*l)
- l = &(*l)->next;
- s = malloc(sizeof(Server)+strlen(name)+1);
- if(s == nil)
- return;
- s->name = (char*)(s+1);
- strcpy(s->name, name);
- s->next = nil;
- *l = s;
- }
- Server*
- copyserverlist(Server *s)
- {
- Server *ns;
- for(ns = nil; s != nil; s = s->next)
- addserver(&ns, s->name);
- return ns;
- }
- /* from here down is copied to ip/snoopy/dns.c periodically to update it */
- /*
- * convert an integer RR type to it's ascii name
- */
- char*
- rrname(int type, char *buf, int len)
- {
- char *t;
- t = nil;
- if(type >= 0 && type <= Tall)
- t = rrtname[type];
- if(t==nil){
- snprint(buf, len, "%d", type);
- t = buf;
- }
- return t;
- }
- /*
- * free a list of resource records and any related structs
- */
- void
- rrfreelist(RR *rp)
- {
- RR *next;
- for(; rp; rp = next){
- next = rp->next;
- rrfree(rp);
- }
- }
- void
- freeserverlist(Server *s)
- {
- Server *next;
- for(; s != nil; s = next){
- next = s->next;
- free(s);
- }
- }
- /*
- * allocate a resource record of a given type
- */
- RR*
- rralloc(int type)
- {
- RR *rp;
- rp = emalloc(sizeof(*rp));
- rp->magic = RRmagic;
- rp->pc = getcallerpc(&type);
- rp->type = type;
- if (rp->type != type)
- dnslog("rralloc: bogus type %d", type);
- setmalloctag(rp, rp->pc);
- switch(type){
- case Tsoa:
- rp->soa = emalloc(sizeof(*rp->soa));
- rp->soa->slaves = nil;
- setmalloctag(rp->soa, rp->pc);
- break;
- case Tsrv:
- rp->srv = emalloc(sizeof(*rp->srv));
- setmalloctag(rp->srv, rp->pc);
- break;
- case Tkey:
- rp->key = emalloc(sizeof(*rp->key));
- setmalloctag(rp->key, rp->pc);
- break;
- case Tcert:
- rp->cert = emalloc(sizeof(*rp->cert));
- setmalloctag(rp->cert, rp->pc);
- break;
- case Tsig:
- rp->sig = emalloc(sizeof(*rp->sig));
- setmalloctag(rp->sig, rp->pc);
- break;
- case Tnull:
- rp->null = emalloc(sizeof(*rp->null));
- setmalloctag(rp->null, rp->pc);
- break;
- }
- rp->ttl = 0;
- rp->expire = 0;
- rp->next = 0;
- return rp;
- }
- /*
- * free a resource record and any related structs
- */
- void
- rrfree(RR *rp)
- {
- DN *dp;
- RR *nrp;
- Txt *t;
- assert(rp->magic == RRmagic);
- assert(!rp->cached);
- /* our callers often hold dnlock. it's needed to examine dp safely. */
- dp = rp->owner;
- if(dp){
- /* if someone else holds dnlock, skip the sanity check. */
- if (canlock(&dnlock)) {
- assert(dp->magic == DNmagic);
- for(nrp = dp->rr; nrp; nrp = nrp->next)
- assert(nrp != rp); /* "rrfree of live rr" */
- unlock(&dnlock);
- }
- }
- switch(rp->type){
- case Tsoa:
- freeserverlist(rp->soa->slaves);
- memset(rp->soa, 0, sizeof *rp->soa); /* cause trouble */
- free(rp->soa);
- break;
- case Tsrv:
- memset(rp->srv, 0, sizeof *rp->srv); /* cause trouble */
- free(rp->srv);
- break;
- case Tkey:
- free(rp->key->data);
- memset(rp->key, 0, sizeof *rp->key); /* cause trouble */
- free(rp->key);
- break;
- case Tcert:
- free(rp->cert->data);
- memset(rp->cert, 0, sizeof *rp->cert); /* cause trouble */
- free(rp->cert);
- break;
- case Tsig:
- free(rp->sig->data);
- memset(rp->sig, 0, sizeof *rp->sig); /* cause trouble */
- free(rp->sig);
- break;
- case Tnull:
- free(rp->null->data);
- memset(rp->null, 0, sizeof *rp->null); /* cause trouble */
- free(rp->null);
- break;
- case Ttxt:
- while(rp->txt != nil){
- t = rp->txt;
- rp->txt = t->next;
- free(t->p);
- memset(t, 0, sizeof *t); /* cause trouble */
- free(t);
- }
- break;
- }
- rp->magic = ~rp->magic;
- memset(rp, 0, sizeof *rp); /* cause trouble */
- free(rp);
- }
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