123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801802803804805806807808809810811812813814815816817818819820821822823824825826827828829830831832833834835836837838839840841842843844845846847848849850851852853854855856857858859860861862863864865866867868869870871872873874875876877878879880881882883884885886887888889890891892893894895896897898899900901902903904905906907908909910911912913914915916917918919920921922923924925926927928929930931932933934935936937938939940941942943944945946947948949950951952953954955956957958959960961962963964965966967968969970971972973974975976977978979980981982983984985986987988989990991992993994995996997998999100010011002100310041005100610071008100910101011101210131014101510161017101810191020102110221023102410251026102710281029103010311032103310341035103610371038103910401041104210431044104510461047104810491050105110521053105410551056105710581059106010611062106310641065106610671068106910701071107210731074107510761077107810791080108110821083108410851086108710881089109010911092109310941095109610971098109911001101110211031104110511061107110811091110111111121113111411151116111711181119112011211122112311241125112611271128112911301131113211331134113511361137113811391140114111421143114411451146114711481149115011511152115311541155115611571158115911601161116211631164116511661167116811691170117111721173117411751176117711781179118011811182118311841185118611871188118911901191119211931194119511961197119811991200120112021203120412051206120712081209121012111212121312141215121612171218121912201221122212231224122512261227122812291230123112321233123412351236123712381239124012411242124312441245124612471248124912501251125212531254125512561257125812591260126112621263126412651266126712681269127012711272127312741275127612771278127912801281128212831284128512861287128812891290129112921293129412951296129712981299130013011302130313041305130613071308130913101311131213131314131513161317131813191320132113221323132413251326132713281329133013311332133313341335133613371338133913401341134213431344134513461347134813491350135113521353135413551356135713581359136013611362136313641365136613671368136913701371137213731374137513761377137813791380138113821383138413851386138713881389139013911392139313941395139613971398139914001401140214031404140514061407140814091410141114121413141414151416141714181419142014211422142314241425142614271428142914301431143214331434143514361437143814391440144114421443144414451446144714481449145014511452145314541455145614571458145914601461146214631464146514661467146814691470147114721473147414751476147714781479148014811482148314841485148614871488148914901491149214931494149514961497149814991500150115021503150415051506150715081509151015111512151315141515151615171518151915201521152215231524152515261527152815291530153115321533153415351536153715381539154015411542154315441545154615471548154915501551155215531554155515561557 |
- #include <u.h>
- #include <libc.h>
- #include <ip.h>
- #include <pool.h>
- #include <ctype.h>
- #include "dns.h"
- /*
- * 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;
- int id;
- } 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",
- [Tkey] "key",
- [Tcert] "cert",
- [Tsig] "sig",
- [Taaaa] "ipv6",
- [Tixfr] "ixfr",
- [Taxfr] "axfr",
- [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",
- };
- /* names of op codes */
- char *opname[] =
- {
- [Oquery] "query",
- [Oinverse] "inverse",
- [Ostatus] "status",
- };
- Lock dnlock;
- static int sencodefmt(Fmt*);
- /*
- * set up a pipe to use as a lock
- */
- 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;
- }
- /*
- * 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 == 0){
- unlock(&dnlock);
- return 0;
- }
- dnvars.names++;
- dp = emalloc(sizeof(*dp));
- dp->magic = DNmagic;
- dp->name = estrdup(name);
- assert(dp->name != 0);
- dp->class = class;
- dp->rr = 0;
- dp->next = 0;
- dp->referenced = now;
- *l = dp;
- unlock(&dnlock);
- return dp;
- }
- /*
- * dump the cache
- */
- void
- dndump(char *file)
- {
- DN *dp;
- int i, fd;
- RR *rp;
- fd = open(file, OWRITE|OTRUNC);
- 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, " %R %c%c %lud/%lud\n", rp, rp->auth?'A':'U',
- rp->db?'D':'N', rp->expire, rp->ttl);
- }
- }
- unlock(&dnlock);
- close(fd);
- }
- /*
- * purge all records
- */
- void
- dnpurge(void)
- {
- DN *dp;
- RR *rp;
- int i;
- lock(&dnlock);
- for(i = 0; i < HTLEN; i++)
- for(dp = ht[i]; dp; dp = dp->next){
- rp = dp->rr;
- dp->rr = nil;
- for(; rp != nil; rp = rp->next)
- rp->cached = 0;
- rrfreelist(dp->rr);
- }
- unlock(&dnlock);
- }
- /*
- * check the age of resource records, free any that have timed out
- */
- void
- dnage(DN *dp)
- {
- RR **l;
- RR *rp, *next;
- ulong diff;
- diff = now - dp->referenced;
- if(diff < Reserved)
- return;
- l = &dp->rr;
- for(rp = dp->rr; rp; rp = next){
- assert(rp->magic == RRmagic && rp->cached);
- next = rp->next;
- if(!rp->db)
- if(rp->expire < now || diff > dnvars.oldest){
- *l = next;
- rp->cached = 0;
- rrfree(rp);
- continue;
- }
- l = &rp->next;
- }
- }
- #define REF(x) if(x) x->refs++
- /*
- * our target is 4000 names cached, this should be larger on large servers
- */
- #define TARGET 4000
- /*
- * 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)
- dnvars.oldest /= 2;
- nextage = now + maxage;
- 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:
- 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 Tmx:
- REF(rp->host);
- 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){
- *l = dp->next;
- if(dp->name)
- free(dp->name);
- dnvars.names--;
- 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;
- static ulong nextage;
- lock(&dnlock);
- /* time out all database entries */
- for(i = 0; i < HTLEN; i++)
- for(dp = ht[i]; dp; dp = dp->next)
- 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)
- {
- DN *dp;
- int i;
- Area *area;
- RR *rp;
- static ulong nextage;
- 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){
- if(rp->ttl < area->soarr->soa->minttl)
- rp->ttl = area->soarr->soa->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 rv;
- if(traceactivity) syslog(0, "dns", "get %d by %d", dnvars.active, getpid());
- lock(&dnvars);
- while(dnvars.mutex){
- unlock(&dnvars);
- sleep(200);
- lock(&dnvars);
- }
- rv = ++dnvars.active;
- now = time(0);
- req->id = ++dnvars.id;
- unlock(&dnvars);
- return rv;
- }
- void
- putactivity(void)
- {
- static ulong lastclean;
- if(traceactivity) syslog(0, "dns", "put %d by %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
- */
- if(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);
- lock(&dnvars);
- }
- unlock(&dnvars);
- db2cache(needrefresh);
- dnageall(0);
- /* let others back in */
- lastclean = now;
- needrefresh = 0;
- dnvars.mutex = 0;
- }
- /*
- * Attach a single resource record to a domain name.
- * - 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
- */
- static void
- rrattach1(RR *new, int auth)
- {
- RR **l;
- RR *rp;
- DN *dp;
- assert(new->magic == RRmagic && !new->cached);
- if(!new->db)
- new->expire = new->ttl;
- 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
- */
- for(rp = *l; rp; rp = *l){
- 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){
- *l = rp->next;
- rp->cached = 0;
- rrfree(rp);
- continue;
- }
- /* all things equal, pick the newer one */
- if(rp->arg0 == new->arg0 && rp->arg1 == new->arg1){
- /* new drives out old */
- if(new->ttl > rp->ttl || new->expire > rp->expire){
- *l = rp->next;
- rp->cached = 0;
- rrfree(rp);
- continue;
- } else {
- rrfree(new);
- return;
- }
- }
- /* Hack for pointer records. This makes sure
- * the ordering in the list reflects the ordering
- * received or read from the database
- */
- if(rp->type == Tptr){
- if(!rp->negative && !new->negative
- && rp->ptr->ordinal > new->ptr->ordinal)
- break;
- }
- }
- l = &rp->next;
- }
- /*
- * add to chain
- */
- new->cached = 1;
- new->next = *l;
- *l = new;
- }
- /*
- * Attach a list of resource records to a domain name.
- * - 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
- */
- void
- rrattach(RR *rp, int auth)
- {
- RR *next;
- lock(&dnlock);
- for(; rp; rp = next){
- next = rp->next;
- rp->next = 0;
- /* avoid any outside spoofing */
- if(cachedb && !rp->db && inmyarea(rp->owner->name))
- rrfree(rp);
- else
- rrattach1(rp, auth);
- }
- unlock(&dnlock);
- }
- /*
- * 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;
- switch(type){
- case Tsoa:
- rp->soa = emalloc(sizeof(*rp->soa));
- rp->soa->slaves = nil;
- break;
- case Tkey:
- rp->key = emalloc(sizeof(*rp->key));
- break;
- case Tcert:
- rp->cert = emalloc(sizeof(*rp->cert));
- break;
- case Tsig:
- rp->sig = emalloc(sizeof(*rp->sig));
- break;
- case Tnull:
- rp->null = emalloc(sizeof(*rp->null));
- 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->cached);
- dp = rp->owner;
- if(dp){
- assert(dp->magic == DNmagic);
- for(nrp = dp->rr; nrp; nrp = nrp->next)
- assert(nrp != rp); /* "rrfree of live rr" */;
- }
- switch(rp->type){
- case Tsoa:
- freeserverlist(rp->soa->slaves);
- free(rp->soa);
- break;
- case Tkey:
- free(rp->key->data);
- free(rp->key);
- break;
- case Tcert:
- free(rp->cert->data);
- free(rp->cert);
- break;
- case Tsig:
- free(rp->sig->data);
- free(rp->sig);
- break;
- case Tnull:
- free(rp->null->data);
- free(rp->null);
- break;
- case Ttxt:
- while(rp->txt != nil){
- t = rp->txt;
- rp->txt = t->next;
- free(t->p);
- free(t);
- }
- break;
- }
- free(rp);
- }
- /*
- * 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);
- }
- }
- extern RR**
- rrcopy(RR *rp, RR **last)
- {
- RR *nrp;
- SOA *soa;
- Key *key;
- Cert *cert;
- Sig *sig;
- Null *null;
- Txt *t, *nt, **l;
- nrp = rralloc(rp->type);
- 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 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);
- }
- if(first)
- goto out;
- /* try for an 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 an 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:
- unlock(&dnlock);
- unique(first);
- 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;
- return atoi(atype);
- }
- /*
- * convert an integer RR type to it's ascii name
- */
- char*
- rrname(int type, char *buf, int len)
- {
- char *t;
- t = 0;
- if(type <= Tall)
- t = rrtname[type];
- if(t==0){
- snprint(buf, len, "%d", type);
- t = buf;
- }
- return t;
- }
- /*
- * return 0 if not a supported rr type
- */
- int
- rrsupported(int type)
- {
- if(type < 0 || type >Tall)
- return 0;
- return rrtname[type] != 0;
- }
- /*
- * 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.
- */
- RR*
- rrcat(RR **start, RR *rp)
- {
- RR **last;
- last = start;
- while(*last != 0)
- 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;
- 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 **nl, *rp;
- RR *first;
- 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;
- }
- /*
- * print conversion for rr records
- */
- int
- rrfmt(Fmt *f)
- {
- RR *rp;
- char *strp;
- Fmt fstr;
- int rv;
- char buf[Domlen];
- Server *s;
- Txt *t;
- fmtstrinit(&fstr);
- rp = va_arg(f->args, RR*);
- if(rp == 0){
- fmtprint(&fstr, "<null>");
- goto out;
- }
- fmtprint(&fstr, "%s %s", rp->owner->name,
- 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", rp->cpu->name, rp->os->name);
- break;
- case Tcname:
- case Tmb:
- case Tmd:
- case Tmf:
- case Tns:
- fmtprint(&fstr, "\t%s", rp->host->name);
- break;
- case Tmg:
- case Tmr:
- fmtprint(&fstr, "\t%s", rp->mb->name);
- break;
- case Tminfo:
- fmtprint(&fstr, "\t%s %s", rp->mb->name, rp->rmb->name);
- break;
- case Tmx:
- fmtprint(&fstr, "\t%lud %s", rp->pref, rp->host->name);
- break;
- case Ta:
- case Taaaa:
- fmtprint(&fstr, "\t%s", rp->ip->name);
- break;
- case Tptr:
- fmtprint(&fstr, "\t%s(%lud)", rp->ptr->name, rp->ptr->ordinal);
- break;
- case Tsoa:
- fmtprint(&fstr, "\t%s %s %lud %lud %lud %lud %lud", rp->host->name,
- rp->rmb->name, rp->soa->serial, rp->soa->refresh, rp->soa->retry,
- rp->soa->expire, rp->soa->minttl);
- for(s = rp->soa->slaves; s != nil; s = s->next)
- fmtprint(&fstr, " %s", s->name);
- break;
- case Tnull:
- 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", rp->rmb->name, rp->rp->name);
- break;
- case Tkey:
- fmtprint(&fstr, "\t%d %d %d", rp->key->flags, rp->key->proto,
- rp->key->alg);
- break;
- case Tsig:
- 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, rp->sig->signer->name);
- break;
- case Tcert:
- fmtprint(&fstr, "\t%d %d %d",
- rp->sig->type, rp->sig->tag, rp->sig->alg);
- break;
- default:
- 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)
- {
- RR *rp;
- char *strp;
- Fmt fstr;
- int rv;
- Server *s;
- Txt *t;
- int quote;
- fmtstrinit(&fstr);
- rp = va_arg(f->args, RR*);
- if(rp == 0){
- fmtprint(&fstr, "<null>");
- goto out;
- }
- if(rp->type == Tptr)
- fmtprint(&fstr, "ptr=%s", rp->owner->name);
- else
- fmtprint(&fstr, "dom=%s", rp->owner->name);
- switch(rp->type){
- case Thinfo:
- fmtprint(&fstr, " cpu=%s os=%s", rp->cpu->name, rp->os->name);
- break;
- case Tcname:
- fmtprint(&fstr, " cname=%s", rp->host->name);
- break;
- case Tmb:
- case Tmd:
- case Tmf:
- fmtprint(&fstr, " mbox=%s", rp->host->name);
- break;
- case Tns:
- fmtprint(&fstr, " ns=%s", rp->host->name);
- break;
- case Tmg:
- case Tmr:
- fmtprint(&fstr, " mbox=%s", rp->mb->name);
- break;
- case Tminfo:
- fmtprint(&fstr, " mbox=%s mbox=%s", rp->mb->name, rp->rmb->name);
- break;
- case Tmx:
- fmtprint(&fstr, " pref=%lud mx=%s", rp->pref, rp->host->name);
- break;
- case Ta:
- case Taaaa:
- fmtprint(&fstr, " ip=%s", rp->ip->name);
- break;
- case Tptr:
- fmtprint(&fstr, " dom=%s", rp->ptr->name);
- break;
- case Tsoa:
- fmtprint(&fstr, " ns=%s mbox=%s serial=%lud refresh=%lud retry=%lud expire=%lud ttl=%lud",
- rp->host->name, rp->rmb->name, rp->soa->serial,
- rp->soa->refresh, rp->soa->retry,
- rp->soa->expire, rp->soa->minttl);
- for(s = rp->soa->slaves; s != nil; s = s->next)
- fmtprint(&fstr, " dnsslave=%s", s->name);
- break;
- case Tnull:
- 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", rp->rmb->name, rp->rp->name);
- break;
- case Tkey:
- fmtprint(&fstr, " flags=%d proto=%d alg=%d",
- rp->key->flags, rp->key->proto, rp->key->alg);
- break;
- case Tsig:
- 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, rp->sig->signer->name);
- break;
- case Tcert:
- fmtprint(&fstr, " type=%d tag=%d alg=%d",
- rp->sig->type, rp->sig->tag, rp->sig->alg);
- break;
- default:
- break;
- }
- out:
- strp = fmtstrflush(&fstr);
- rv = fmtstrcpy(f, strp);
- free(strp);
- return rv;
- }
- void
- warning(char *fmt, ...)
- {
- char dnserr[128];
- va_list arg;
- va_start(arg, fmt);
- vseprint(dnserr, dnserr+sizeof(dnserr), fmt, arg);
- va_end(arg);
- syslog(1, "dns", dnserr);
- }
- /*
- * create a slave process to handle a request to avoid one request blocking
- * another
- */
- void
- slave(Request *req)
- {
- static int slaveid;
- if(req->isslave)
- return; /* we're already a slave process */
- /* limit parallelism */
- if(getactivity(req) > Maxactive){
- putactivity();
- return;
- }
- switch(rfork(RFPROC|RFNOTEG|RFMEM|RFNOWAIT)){
- case -1:
- putactivity();
- break;
- case 0:
- req->isslave = 1;
- break;
- default:
- longjmp(req->mret, 1);
- }
- }
- /*
- * chasing down double free's
- */
- void
- dncheck(void *p, int dolock)
- {
- int i;
- DN *dp;
- RR *rp;
- extern Pool *mainmem;
- 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);
- }
- }
- 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;
- }
- 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)
- return 0;
- if(cistrcmp(lower + ln - hn, higher) != 0)
- return 0;
- if(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 and mx's */
- for(x = rp; x; x = x->next)
- if(x->type != Ta && 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)
- {
- char *out;
- char *buf;
- int i, len;
- int ilen;
- int rv;
- 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();
- 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);
- 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;
- }
- /*
- * look for all ip addresses in this network and make
- * pointer records for them.
- */
- void
- dnptr(uchar *net, uchar *mask, char *dom, int bytes, int ttl)
- {
- int i, j;
- DN *dp;
- RR *rp, *nrp, *first, **l;
- uchar ip[IPaddrlen];
- uchar nnet[IPaddrlen];
- char ptr[Domlen];
- char *p, *e;
- 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 != Ta || rp->negative)
- continue;
- parseip(ip, rp->ip->name);
- maskip(ip, mask, nnet);
- if(ipcmp(net, nnet) != 0)
- continue;
- p = ptr;
- e = ptr+sizeof(ptr);
- for(j = IPaddrlen-1; j >= IPaddrlen-bytes; j--)
- p = seprint(p, e, "%d.", ip[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, 1);
- }
- }
- void
- freeserverlist(Server *s)
- {
- Server *next;
- for(; s != nil; s = next){
- next = s->next;
- free(s);
- }
- }
- 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;
- }
|