+++ /dev/null
-/* nonamed - Not a name daemon, but plays one on TV.
- * Author: Kees J. Bot
- * 29 Nov 1994
- */
-static const char version[] = "2.7";
-
-/* Use the file reading gethostent() family of functions. */
-#define sethostent _sethostent
-#define gethostent _gethostent
-#define endhostent _endhostent
-
-#define nil ((void*)0)
-#include <sys/types.h>
-#include <stdio.h>
-#include <syslog.h>
-#include <stddef.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <errno.h>
-#include <string.h>
-#include <time.h>
-#include <limits.h>
-#include <signal.h>
-#include <assert.h>
-#include <sys/stat.h>
-#include <sys/ioctl.h>
-#include <sys/asynchio.h>
-#include <netinet/in.h>
-#include <arpa/nameser.h>
-#include <net/hton.h>
-#include <net/netlib.h>
-#include <net/gen/in.h>
-#include <net/gen/inet.h>
-#include <arpa/nameser.h>
-#include <resolv.h>
-#include <netdb.h>
-#include <net/gen/socket.h>
-#include <net/gen/tcp.h>
-#include <net/gen/tcp_io.h>
-#include <net/gen/udp.h>
-#include <net/gen/udp_hdr.h>
-#include <net/gen/udp_io.h>
-#include <net/gen/dhcp.h>
-#include <arpa/inet.h>
-
-#include <paths.h>
-#include <minix/paths.h>
-
-#undef HTONL
-#undef HTONS
-#define HTONL htonl
-#define HTONS htons
-
-#define HTTL 3600L /* Default time to live for /etc/hosts data. */
-#define SHORT_TIMEOUT 2 /* If you expect an answer soon. */
-#define MEDIUM_TIMEOUT 4 /* Soon, but not that soon. */
-#define LONG_TIMEOUT 300 /* For stream connections to a real named. */
-#define N_IDS 256 /* Keep track of this many queries. */
-#define N_DATAMAX (4096*sizeof(char *)) /* Default response cache size. */
-#define N_NAMEDS 8 /* Max # name daemons we can keep track of. */
-#define NO_FD (-1) /* No name daemon channel here. */
-#define T_NXD ((u16_t) -1) /* A "type" signalling a nonexistent domain. */
-
-/* Can't do async I/O under standard Minix, so forget about TCP. */
-#define DO_TCP (__minix_vmd || !__minix)
-
-/* Host data, file to store our process id in, our cache, DHCP's cache. */
-static char HOSTS[]= _PATH_HOSTS;
-static char PIDFILE[]= "/usr/run/nonamed.pid";
-static char NNCACHE[]= "/usr/adm/nonamed.cache";
-static char DHCPCACHE[]= _PATH_DHCPCACHE;
-
-/* Magic string to head the cache file. */
-static char MAGIC[4]= "NND\2";
-
-#define arraysize(a) (sizeof(a) / sizeof((a)[0]))
-#define arraylimit(a) ((a) + arraysize(a))
-#define between(a, c, z) ((unsigned) ((c) - (a)) <= (unsigned) ((z) - (a)))
-
-/* The start of time and the far future. */
-#define IMMEDIATE ((time_t) 0)
-#define NEVER ((time_t) ((time_t) -1 < 0 ? LONG_MAX : ULONG_MAX))
-
-static unsigned debug; /* Debug level. */
-static time_t now; /* Current time. */
-static u32_t stale; /* Extension time for stale data. */
-static u32_t httl; /* TTL for /etc/hosts data. */
-static int reinit, done; /* Reinit config / program is done. */
-static int single; /* Run single on a nondefault interface. */
-static int localonly; /* Only accept local queries. */
-#define LOCALHOST 0x7F000001
-
-static void report(const char *label)
-{
- fprintf(stderr, "nonamed: %s: %s\n", label, strerror(errno));
-}
-
-static void fatal(const char *label)
-{
- report(label);
- if (debug >= 3) { fflush(nil); abort(); }
- exit(1);
-}
-
-static void *allocate(void *mem, size_t size)
-{
- if ((mem= realloc(mem, size)) == nil) fatal("malloc()");
- return mem;
-}
-
-static void deallocate(void *mem)
-{
- free(mem);
-}
-
-static char *timegmt(time_t t)
-/* Simple "time in seconds to GMT time today" converter. */
-{
- unsigned h, m, s;
- static char asctime[sizeof("00:00:00")];
-
- s= t % 60;
- t /= 60;
- m= t % 60;
- t /= 60;
- h= t % 24;
- sprintf(asctime, "%02u:%02u:%02u", h, m, s);
- return asctime;
-}
-
-static char *nowgmt(void)
-{
- return timegmt(now);
-}
-
-static char *my_ntoa(ipaddr_t addr)
-{
- return inet_ntoa(*(struct in_addr *)&addr);
-}
-
-#define PC(n) ((void) sizeof(char [sizeof(*(n)) == 1]), (char *) (n))
-#define namecpy(n1, n2) strcpy(PC(n1), PC(n2))
-#define namecat(n1, n2) strcat(PC(n1), PC(n2))
-#define namechr(n, c) ((u8_t *) strchr(PC(n), (c)))
-#define namecmp(n1, n2) strcasecmp(PC(n1), PC(n2))
-#define namencmp(n1, n2, len) strncasecmp(PC(n1), PC(n2), len)
-
-typedef struct dns { /* A DNS packet. */
- HEADER hdr; /* DNS header. */
- u8_t data[PACKETSZ - sizeof(HEADER)]; /* DNS data. */
-} dns_t;
-
-/* Addres of DNS packet to octet address, or vv. */
-#define dns2oct(dp) ((u8_t *) (dp))
-#define oct2dns(dp) ((dns_t *) (dp))
-
-typedef struct query { /* One cached answer to a query. */
- struct query *less; /* Less recently used. */
- struct query *more; /* More recently used. */
- time_t age; /* Time it was added. */
- time_t stale; /* Time it goes stale by TTL. */
- u16_t usage; /* Counts of queries answered. */
- u8_t flags; /* QF_REFRESH. */
- size_t size; /* Size of DNS packet. */
- dns_t dns; /* Answer to query as a DNS packet. */
-} query_t;
-
-#define QF_REFRESH 0x01 /* This stale data must be refreshed. */
-#define QU_SHIFT 1 /* To shift usage by when evicting. */
-
-/* Size of new query_t or existing query_t. */
-#define query_allocsize(dnssize) (offsetof(query_t, dns) + (dnssize))
-#define query_size(qp) query_allocsize((qp)->size)
-
-static query_t *mru, *lru; /* Most and least recently used answers. */
-static int q_refresh; /* Set when an entry needs refreshing. */
-
-static void pack16(u8_t *buf, u16_t s)
-/* Pack a 16 bit value into a byte array. */
-{
- buf[0]= ((u8_t *) &s)[0];
- buf[1]= ((u8_t *) &s)[1];
-}
-
-static void pack32(u8_t *buf, u32_t l)
-/* Pack a 32 bit value into a byte array. */
-{
- buf[0]= ((u8_t *) &l)[0];
- buf[1]= ((u8_t *) &l)[1];
- buf[2]= ((u8_t *) &l)[2];
- buf[3]= ((u8_t *) &l)[3];
-}
-
-static u16_t upack16(u8_t *buf)
-/* Unpack a 16 bit value from a byte array. */
-{
- u16_t s;
-
- ((u8_t *) &s)[0]= buf[0];
- ((u8_t *) &s)[1]= buf[1];
- return s;
-}
-
-static u32_t upack32(u8_t *buf)
-/* Unpack a 32 bit value from a byte array. */
-{
- u32_t l;
-
- ((u8_t *) &l)[0]= buf[0];
- ((u8_t *) &l)[1]= buf[1];
- ((u8_t *) &l)[2]= buf[2];
- ((u8_t *) &l)[3]= buf[3];
- return l;
-}
-
-/* Encoding of RRs: i(paddr), d(omain), l(ong), c(har), s(tring), (s)h(ort). */
-static char *encoding[] = {
- "c*", /* anything unknown is c* */
- "i", /* A */
- "d", /* NS */
- "d", /* MD */
- "d", /* MF */
- "d", /* CNAME */
- "ddlllll", /* SOA */
- "d", /* MB */
- "d", /* MG */
- "d", /* MR */
- "c*", /* NULL */
- "icc*", /* WKS */
- "d", /* PTR */
- "ss", /* HINFO */
- "dd", /* MINFO */
- "hd", /* MX */
- "s*", /* TXT */
-};
-
-static char *itoa(char *fmt, u32_t i)
-{
- static char output[32 + 3 * sizeof(i)];
-
- sprintf(output, fmt, (unsigned long) i);
- return output;
-}
-
-static char *classname(unsigned class)
-/* Class name of a resource record, for debug purposes. */
-{
- static char *classes[] = { "IN", "CS", "CHAOS", "HS" };
-
- if ((class - C_IN) < arraysize(classes)) return classes[class - C_IN];
- return itoa("C_%u", class);
-}
-
-static char *typename(unsigned type)
-/* Type name of a resource record, for debug purposes. */
-{
- static char type_A[][6] = {
- "A", "NS", "MD", "MF", "CNAME", "SOA", "MB", "MG", "MR", "NULL",
- "WKS", "PTR", "HINFO", "MINFO", "MX", "TXT",
- };
- static char type_AXFR[][6] = {
- "AXFR", "MAILB", "MAILA", "ANY",
- };
- if ((type - T_A) < arraysize(type_A)) return type_A[type - T_A];
- if ((type - T_AXFR) < arraysize(type_AXFR)) return type_AXFR[type - T_AXFR];
- return itoa("T_%u", type);
-}
-
-static int print_qrr(dns_t *dp, size_t size, u8_t *cp0, int q)
-/* Print a query (q) or resource record (!q) from 'cp0' in a DNS packet for
- * debug purposes. Return number of bytes skipped or -1 on error.
- */
-{
- u8_t name[MAXDNAME+1];
- u8_t *cp;
- char *ep;
- u8_t *dlim, *rlim;
- u16_t type, class, rdlength;
- u32_t ttl;
- int r;
-
- cp= cp0;
- dlim= dns2oct(dp) + size;
- r= dn_expand(dns2oct(dp), dlim, cp, name, MAXDNAME);
- if (r == -1) return -1;
- cp += r;
- if (cp + 2 * sizeof(u16_t) > dlim) return -1;
- type= ntohs(upack16(cp));
- cp += sizeof(u16_t);
- class= ntohs(upack16(cp));
- cp += sizeof(u16_t);
- printf("%-25s", (char *) name);
- if (q) {
- /* We're just printing a query segment, stop right here. */
- printf(" %8s", classname(class));
- printf(" %-5s", typename(type));
- return cp - cp0;
- }
- if (cp + sizeof(u32_t) + sizeof(u16_t) > dlim) return -1;
- ttl= ntohl(upack32(cp));
- cp += sizeof(u32_t);
- rdlength= ntohs(upack16(cp));
- cp += sizeof(u16_t);
- if (cp + rdlength > dlim) return -1;
- rlim = cp + rdlength;
- printf(" %5lu", (unsigned long) ttl);
- printf(" %s", classname(class));
- printf(" %-5s", typename(type));
- ep= type < arraysize(encoding) ? encoding[type] : encoding[0];
- while (*ep != 0) {
- switch (*ep++) {
- case 'i':
- if (cp + sizeof(u32_t) > rlim) return -1;
- printf(" %s", my_ntoa(upack32(cp)));
- cp += sizeof(u32_t);
- break;
- case 'l':
- if (cp + sizeof(u32_t) > rlim) return -1;
- printf(" %ld", (long)(i32_t) ntohl(upack32(cp)));
- cp += sizeof(u32_t);
- break;
- case 'd':
- r= dn_expand(dns2oct(dp), dlim, cp, name, MAXDNAME);
- if (r == -1) return -1;
- printf(" %s", (char *) name);
- cp += r;
- break;
- case 'c':
- if (cp >= rlim) return -1;
- printf(" %02X", *cp++);
- break;
- case 's':
- r= *cp + 1;
- if (cp + r > rlim) return -1;
- printf(" \"%.*s\"", *cp, (char *) (cp + 1));
- cp += r;
- break;
- case 'h':
- if (cp + sizeof(u16_t) > rlim) return -1;
- printf(" %u", ntohs(upack16(cp)));
- cp += sizeof(u16_t);
- break;
- }
- if (*ep == '*') ep= cp < rlim ? ep-1 : ep+1;
- }
- return cp - cp0;
-}
-
-static void dns_tell(int indent, dns_t *dp, size_t size)
-/* Explain a DNS packet, for debug purposes. */
-{
- u8_t *cp;
- int r, i;
- unsigned count[4];
- static char label[4][4]= { "QD:", "AN:", "NS:", "AR:" };
- static char rcodes[][9] = {
- "NOERROR", "FORMERR", "SERVFAIL", "NXDOMAIN", "NOTIMP", "REFUSED"
- };
-
- if (size < sizeof(HEADER)) return;
-
- printf("%*s", indent, "");
- printf("DNS %s:", (dp->hdr.qr) ? "reply" : "query");
- r = dp->hdr.rcode;
- printf(" %s", r < arraysize(rcodes) ? rcodes[r] : itoa("ERR_%lu", r));
- if (dp->hdr.aa) printf(" AA");
- if (dp->hdr.tc) printf(" TC");
- if (dp->hdr.rd) printf(" RD");
- if (dp->hdr.ra) printf(" RA");
- if (dp->hdr.ad) printf(" AD");
- if (dp->hdr.cd) printf(" CD");
- fputc('\n', stdout);
-
- count[0]= ntohs(dp->hdr.qdcount);
- count[1]= ntohs(dp->hdr.ancount);
- count[2]= ntohs(dp->hdr.nscount);
- count[3]= ntohs(dp->hdr.arcount);
- cp = dp->data;
- for (i= 0; i < 4; i++) {
- while (count[i] > 0) {
- printf("%*s", indent, "");
- printf(" %s ", label[i]);
- r= print_qrr(dp, size, cp, (i == 0));
- fputc('\n', stdout);
- if (r == -1) return;
- cp += r;
- count[i]--;
- }
- }
-}
-
-static u32_t dns_ttl(dns_t *dp, size_t size, u32_t delta)
-/* Compute the minimum TTL of all RRs in a DNS packet and subtract delta from
- * all TTLs. (We are actually only interested in the minimum (delta = 0) or
- * the subtraction (delta > 0). It was easier to roll this into one routine.)
- */
-{
- u8_t *cp, *rdp, *dlim;
- int r, i, hasttl, hassoa;
- unsigned type, count[4];
- u32_t ttl, minimum, minttl;
- unsigned rcode;
- u8_t name[MAXDNAME+1];
-
- hasttl= hassoa= 0;
- minttl= 365*24*3600L;
- dlim= dns2oct(dp) + size;
- if (size < sizeof(HEADER)) return 0;
-
- rcode= dp->hdr.rcode;
- count[0]= ntohs(dp->hdr.qdcount);
- count[1]= ntohs(dp->hdr.ancount);
- count[2]= ntohs(dp->hdr.nscount);
- count[3]= ntohs(dp->hdr.arcount);
- cp = dp->data;
- for (i= 0; i < 4 && cp < dlim; i++) {
- while (count[i] > 0) {
- r= dn_expand(dns2oct(dp), dlim, cp, name, MAXDNAME);
- if (r == -1) break;
- cp += r + 2 * sizeof(u16_t);
- if (i != 0) {
- if (cp + sizeof(u32_t) + sizeof(u16_t) > dlim) break;
- type= upack16(cp - 2 * sizeof(u16_t));
- ttl= ntohl(upack32(cp));
- ttl= ttl < delta ? 0 : ttl - delta;
- if (rcode == NXDOMAIN && i == 2 && type == HTONS(T_SOA)) {
- rdp= cp + sizeof(u32_t) + sizeof(u16_t);
- r= dn_expand(dns2oct(dp), dlim, rdp, name, MAXDNAME);
- if (r == -1) break;
- rdp += r;
- r= dn_expand(dns2oct(dp), dlim, rdp, name, MAXDNAME);
- if (r == -1) break;
- rdp += r + 4 * sizeof(u32_t);
- if (rdp + sizeof(u32_t) > dlim) break;
- minimum= ntohl(upack32(rdp));
- if (ttl > minimum) ttl= minimum;
- hassoa= 1;
- }
- if (delta != 0) pack32(cp, htonl(ttl));
- if (ttl < minttl) minttl= ttl;
- hasttl= 1;
- cp += sizeof(u32_t);
- cp += sizeof(u16_t) + ntohs(upack16(cp));
- }
- count[i]--;
- }
- }
- return ((rcode == NOERROR && hasttl) || (rcode == NXDOMAIN && hassoa))
- ? minttl : 0;
-}
-
-/* Total cached query data. */
-static size_t n_datamax= N_DATAMAX;
-static size_t n_data;
-
-static query_t *extract_query(query_t *qp)
-/* Take a query out of the query cache. */
-{
- assert(qp != nil);
- *(qp->less != nil ? &qp->less->more : &lru) = qp->more;
- *(qp->more != nil ? &qp->more->less : &mru) = qp->less;
- n_data -= query_size(qp);
- return qp;
-}
-
-static query_t *get_query(u8_t *name, unsigned type)
-/* Find a query and if so remove it from the cache and return it. */
-{
- query_t *qp, *less;
- u8_t qname[MAXDNAME+1];
- int r;
-
- for (qp= mru; qp != nil; qp= less) {
- less= qp->less;
- if (qp->stale <= now - stale) {
- /* This answer has expired. */
- deallocate(extract_query(qp));
- } else {
- r= dn_expand(dns2oct(&qp->dns), dns2oct(&qp->dns) + qp->size,
- qp->dns.data, qname, MAXDNAME);
- if (r == -1) continue;
- if (namecmp(qname, name) == 0 && upack16(qp->dns.data+r) == type) {
- /* Found an answer to the query. */
- return extract_query(qp);
- }
- }
- }
- return nil;
-}
-
-static void insert_query(query_t *qp)
-/* (Re)insert a query into the cache. */
-{
- *(qp->less != nil ? &qp->less->more : &lru) = qp;
- *(qp->more != nil ? &qp->more->less : &mru) = qp;
- n_data += query_size(qp);
-
- /* Try to delete the LRU while there is too much memory in use. If
- * its usage count is too high then it gets a second chance.
- */
- while (n_data > n_datamax && lru != nil) {
- if ((lru->usage >>= QU_SHIFT) == 0 || lru->stale <= now - stale) {
- deallocate(extract_query(lru));
- } else {
- lru->less= mru; /* Make list circular. */
- mru->more= lru;
- mru= lru; /* Move one over, making LRU the MRU. */
- lru= lru->more;
- lru->less= nil; /* Break the circle. */
- mru->more= nil;
- }
- }
-
- if (debug >= 2) {
- unsigned n= 0;
- for (qp= mru; qp != nil; qp= qp->less) n++;
- printf("%u cached repl%s, %u bytes, sbrk(0) = %u\n",
- n, n == 1 ? "y" : "ies",
- (unsigned) n_data,
- (unsigned) sbrk(0));
- }
-}
-
-static void put_query(query_t *qp)
-/* Add a new query to the cache as the MRU. */
-{
- qp->less= mru;
- qp->more= nil;
- insert_query(qp);
-}
-
-static void cache2file(void)
-/* Store the cached data into the cache file. */
-{
- FILE *fp;
- query_t *qp;
- u8_t data[4+1+2+2];
- u16_t usage;
- char newcache[sizeof(NNCACHE) + sizeof(".new")];
-
- if (single) return;
-
- strcpy(newcache, NNCACHE);
- strcat(newcache, ".new");
-
- if ((fp= fopen(newcache, "w")) == nil) {
- if ((errno != ENOENT && errno != EROFS) || debug >= 2) report(newcache);
- return;
- }
- if (debug >= 2) printf("Writing %s:\n", newcache);
-
- /* Magic number: */
- fwrite(MAGIC, 1, sizeof(MAGIC), fp);
-
- for (qp= lru; qp != nil; qp= qp->more) {
- if (qp->stale <= now - stale) continue;
- if (debug >= 2) {
- printf("Usage = %u, Age = %ld, Flags = %02X:\n",
- qp->usage, (long) (now - qp->age), qp->flags);
- dns_tell(2, &qp->dns, qp->size);
- }
- pack32(data+0, htonl(qp->age));
- data[4]= qp->flags;
- pack16(data+5, htons(qp->size));
- pack16(data+7, htons(qp->usage));
- fwrite(data, 1, sizeof(data), fp);
- fwrite(&qp->dns, 1, qp->size, fp);
- if (ferror(fp)) break;
- }
-
- if (ferror(fp) || fclose(fp) == EOF) {
- report(newcache);
- (void) unlink(newcache);
- return;
- }
-
- if (debug >= 2) printf("mv %s %s\n", newcache, NNCACHE);
- if (rename(newcache, NNCACHE) < 0) {
- fprintf(stderr, "nonamed: mv %s %s: %s\n",
- newcache, NNCACHE, strerror(errno));
- (void) unlink(newcache);
- }
-}
-
-static void file2cache(void)
-/* Read cached data from the cache file. */
-{
- query_t *qp;
- FILE *fp;
- u8_t data[4+1+2+2];
- size_t dlen;
-
- if (single) return;
-
- if ((fp= fopen(NNCACHE, "r")) == nil) {
- if (errno != ENOENT || debug >= 2) report(NNCACHE);
- return;
- }
- if (debug >= 2) printf("Reading %s:\n", NNCACHE);
-
- /* Magic number? */
- fread(data, 1, sizeof(MAGIC), fp);
- if (ferror(fp) || memcmp(MAGIC, data, sizeof(MAGIC)) != 0) goto err;
-
- for (;;) {
- fread(data, 1, sizeof(data), fp);
- if (feof(fp) || ferror(fp)) break;
- dlen= ntohs(upack16(data+5));
- qp= allocate(nil, query_allocsize(dlen));
- qp->age= htonl(upack32(data+0));
- qp->flags= data[4];
- if (qp->flags & QF_REFRESH) q_refresh= 1;
- qp->size= dlen;
- qp->usage= htons(upack16(data+7));
- fread(&qp->dns, 1, qp->size, fp);
- if (feof(fp) || ferror(fp)) {
- deallocate(qp);
- goto err;
- }
- qp->stale= qp->age + dns_ttl(&qp->dns, dlen, 0);
- if (debug >= 2) {
- printf("Usage = %u, Age = %ld, Flags = %02X:\n",
- qp->usage, (long) (now - qp->age), qp->flags);
- dns_tell(2, &qp->dns, dlen);
- }
- put_query(qp);
- }
- if (ferror(fp)) {
- err:
- /* The cache file did not end at EOF or is otherwise a mess. */
- fprintf(stderr, "nonamed: %s: %s\n", NNCACHE,
- ferror(fp) ? strerror(errno) : "Corrupt");
- while (lru != nil) deallocate(extract_query(lru));
- }
- fclose(fp);
-}
-
-typedef int handler_t(void *data, int expired);
-
-/* All actions are in the form of "jobs". */
-typedef struct job {
- struct job *next, **prev; /* To make a job queue. */
- handler_t *handler; /* Function to handle this job. */
- time_t timeout; /* Moment it times out. */
- void *data; /* Data associated with the job. */
-} job_t;
-
-static job_t *queue; /* Main job queue. */
-
-static void newjob(handler_t *handler, time_t timeout, void *data)
-/* Create a new job with the given handler, timeout time and data. */
-{
- job_t *job, **prev;
-
- job= allocate(nil, sizeof(*job));
- job->handler= handler;
- job->timeout= timeout;
- job->data= data;
-
- for (prev= &queue; *prev != nil; prev= &(*prev)->next) {
- if (job->timeout < (*prev)->timeout) break;
- }
- job->next= *prev;
- job->prev= prev;
- *prev= job;
- if (job->next != nil) job->next->prev= &job->next;
-}
-
-static int execjob(job_t *job, int expired)
-/* Execute a job by calling the handler. Remove the job if it returns true,
- * indicating that it is done. Expired is set if the job timed out. It is
- * otherwise called to check for I/O.
- */
-{
- if ((*job->handler)(job->data, expired)) {
- *job->prev= job->next;
- if (job->next != nil) job->next->prev= job->prev;
- deallocate(job);
- return 1;
- }
- return 0;
-}
-
-static void force_expire(handler_t *handler)
-/* Force jobs to expire immediately, the named searcher for instance. */
-{
- job_t *job, **prev= &queue;
-
- while ((job= *prev) != nil) {
- if (job->handler == handler && job->timeout != IMMEDIATE) {
- *prev= job->next;
- if (job->next != nil) job->next->prev= prev;
- newjob(job->handler, IMMEDIATE, job->data);
- deallocate(job);
- } else {
- prev= &job->next;
- }
- }
-}
-
-static int nxdomain(u8_t *name)
-/* True iff the two top level components in a name are repeated in the name,
- * or if in-addr.arpa is found within a name. Such things happen often in a
- * search for an already fully qualified local name. For instance:
- * flotsam.cs.vu.nl.cs.vu.nl. (We don't want this at boot time.)
- */
-{
- u8_t *end, *top, *p;
- size_t n;
-
- end= namechr(name, 0);
- top= end;
- while (top > name && *--top != '.') {}
- while (top > name && *--top != '.') {}
- n= end - top;
- p= top;
- for (;;) {
- if (p == name) return 0;
- if (*--p == '.') {
- if (namencmp(p, top, n) == 0 && p[n] == '.') return 1;
- if (namencmp(p, ".in-addr.arpa.", 14) == 0) return 1;
- }
- }
-}
-
-typedef struct id2id {
- u16_t id; /* ID of old query. */
- u16_t port; /* Reply port. */
- ipaddr_t ip; /* Reply address. */
-} id2id_t;
-
-static id2id_t id2id[N_IDS];
-static u16_t id_counter;
-
-static u16_t new_id(u16_t in_id, u16_t in_port, ipaddr_t in_ip)
-/* An incoming UDP query must be relabeled with a new ID before it can be
- * send on to a real name daemon.
- */
-{
- id2id_t *idp;
- u16_t id;
-
- id= id_counter++;
- idp= &id2id[id % N_IDS];
- idp->id= in_id;
- idp->port= in_port;
- idp->ip= in_ip;
- return htons(id);
-}
-
-static int old_id(u16_t id, u16_t *out_id, u16_t *out_port, ipaddr_t *out_ip)
-/* Translate a reply id back to the id, port, and address used in the query.
- * Return true if the translation is possible.
- */
-{
- id= ntohs(id);
- if ((u16_t) (id_counter - id) > N_IDS) {
- /* Too old. */
- return 0;
- } else {
- /* We know this one. */
- id2id_t *idp= &id2id[id % N_IDS];
-
- if (idp->port == 0) return 0; /* Named is trying to fool us? */
- *out_id= idp->id;
- *out_port= idp->port;
- *out_ip= idp->ip;
- idp->port= 0;
- return 1;
- }
-}
-
-/* IDs used to mark my own queries to name servers, must be new_id translated
- * to make them unique "on the wire".
- */
-#define ID_IPSELF HTONL(0) /* "I did it myself" address. */
-#define ID_PROBE HTONS(0) /* Name server probe. */
-#define ID_REFRESH HTONS(1) /* Query to refresh a cache entry. */
-
-static char *tcp_device, *udp_device; /* TCP and UDP device names. */
-static int udp_fd; /* To send or receive UDP packets. */
-static asynchio_t asyn; /* For I/O in progress. */
-static ipaddr_t my_ip; /* My IP address. */
-static u16_t my_port, named_port; /* Port numbers, normally "domain". */
-
-static ipaddr_t named[N_NAMEDS]; /* Addresses of all name servers. */
-static unsigned n_nameds; /* Number of configured name daemons. */
-static unsigned i_named; /* Index to current name server. */
-static int expect; /* Set when we expect an answer. */
-static int search_ct= -1; /* Named search count and state. */
-static int dirty; /* True when new entry put in cache. */
-
-#define current_named() (+named[i_named])
-#define searching() (search_ct > 0)
-#define start_searching() ((void) (search_ct= -1))
-#define stop_searching() ((void) (search_ct= 0))
-#define expecting() (+expect)
-#define start_expecting() ((void) (expect= 1))
-#define stop_expecting() ((void) (expect= 0))
-
-static time_t filetime(const char *file)
-/* Get the modified time of a file. */
-{
- struct stat st;
-
- return stat(file, &st) == 0 ? st.st_mtime : 0;
-}
-
-static void init_config(ipaddr_t ifip)
-/* Read name daemon list and other special stuff from the hosts file. */
-{
- struct hostent *he;
- u32_t nip, hip;
- static time_t hosts_time, dhcp_time;
- time_t ht, dt;
-
- /* See if anything really changed. */
- if (((ifip ^ HTONL(LOCALHOST)) & HTONL(0xFF000000)) == 0) ifip= my_ip;
- ht= filetime(HOSTS);
- dt= filetime(DHCPCACHE);
- if (ifip == my_ip && ht == hosts_time && dt == dhcp_time) return;
- my_ip= ifip;
- hosts_time= ht;
- dhcp_time= dt;
-
- if (debug >= 2) {
- printf("%s: I am nonamed %s at %s:%u\n",
- nowgmt(), version, my_ntoa(my_ip), ntohs(my_port));
- }
-
- httl= HTONL(HTTL);
- stale= 0;
- n_nameds= 0;
-
- if (!single) {
- sethostent(0);
- while ((he= gethostent()) != nil) {
- memcpy(&nip, he->h_addr, sizeof(u32_t));
- hip= ntohl(nip);
- if (namecmp(he->h_name, "%ttl") == 0) httl= nip;
- if (namecmp(he->h_name, "%stale") == 0) stale= hip;
- if (namecmp(he->h_name, "%memory") == 0) n_datamax= hip;
- if (namecmp(he->h_name, "%nameserver") == 0) {
- if (nip != my_ip || named_port != my_port) {
- if (n_nameds < N_NAMEDS) named[n_nameds++]= nip;
- }
- }
- }
- endhostent();
- }
-
- if (n_nameds == 0) {
- /* No name daemons found in the host file. What about DHCP? */
- int fd;
- dhcp_t d;
- ssize_t r;
- u8_t *data;
- size_t len;
-
- if ((fd= open(DHCPCACHE, O_RDONLY)) < 0) {
- if (errno != ENOENT) fatal(DHCPCACHE);
- } else {
- while ((r= read(fd, &d, sizeof(d))) == sizeof(d)) {
- if (d.yiaddr == my_ip) break;
- }
- if (r < 0) fatal(DHCPCACHE);
- close(fd);
-
- if (r == sizeof(d) && dhcp_gettag(&d, DHCP_TAG_DNS, &data, &len)) {
- while (len >= sizeof(nip)) {
- memcpy(&nip, data, sizeof(nip));
- data += sizeof(nip);
- len -= sizeof(nip);
- if (nip != my_ip || named_port != my_port) {
- if (n_nameds < N_NAMEDS) named[n_nameds++]= nip;
- }
- }
- }
- }
- }
- i_named= 0;
-}
-
-static handler_t job_save_cache, job_read_udp, job_find_named, job_expect_named;
-#if DO_TCP
-static handler_t job_setup_listen, job_listen, job_setup_connect, job_connect;
-static handler_t job_read_query, job_write_query;
-static handler_t job_read_reply, job_write_reply;
-#endif
-
-static int query_hosts(u8_t *qname, unsigned type, dns_t *dp, size_t *pdlen)
-/* Read the /etc/hosts file to try and answer an A or PTR query. Return
- * true iff an answer can be found, with the answer copied to *dp.
- */
-{
- struct hostent *he;
- int i, r;
- dns_t dns;
- u8_t *domain;
- u8_t *cp;
- u8_t name[MAXDNAME+1];
- u8_t *dnvec[40];
- unsigned ancount;
- struct hostent localhost;
- static char *noaliases[]= { nil };
- static ipaddr_t localaddr;
- static char *localaddrlist[]= { (char *) &localaddr, nil };
-
- localaddr = HTONL(LOCALHOST);
-
- if (single) return 0;
-
- /* Assume we can answer. */
- dns.hdr.qr = 1;
- dns.hdr.opcode = 0;
- dns.hdr.aa = 1;
- dns.hdr.tc = 0;
- dns.hdr.rd = 0;
- dns.hdr.ra = 1;
- dns.hdr.unused = 0;
- dns.hdr.ad = 0;
- dns.hdr.cd = 0;
- dns.hdr.rcode = 0;
- dns.hdr.qdcount= HTONS(1);
- ancount= 0;
- dns.hdr.nscount= HTONS(0);
- dns.hdr.arcount= HTONS(0);
-
- dnvec[0]= dns2oct(&dns);
- dnvec[1]= nil;
- cp= dns.data;
- r= dn_comp(qname, cp, arraysize(dns.data), dnvec, arraylimit(dnvec));
- if (r == -1) return 0;
- cp += r;
- pack16(cp, type);
- cp += sizeof(u16_t);
- pack16(cp, HTONS(C_IN));
- cp += sizeof(u16_t);
-
- /* Localhost is fixed to 127.0.0.1. */
- localhost.h_name=
- namencmp(qname, "localhost.", 10) == 0 ? (char *) qname : "localhost";
- localhost.h_aliases= noaliases;
- localhost.h_addr_list= localaddrlist;
- he= &localhost;
-
- sethostent(0);
- do {
- int type_host = NTOHS(type);
- switch (type_host) {
- case T_A:
- if (namecmp(qname, he->h_name) == 0) {
- addA:
- r= dn_comp((u8_t *) he->h_name, cp, arraylimit(dns.data) - cp,
- dnvec, arraylimit(dnvec));
- if (r == -1) return 0;
- cp += r;
- if (cp + 3 * sizeof(u16_t) + 2 * sizeof(u32_t)
- > arraylimit(dns.data)) { r= -1; break; }
- pack16(cp, HTONS(T_A));
- cp += sizeof(u16_t);
- pack16(cp, HTONS(C_IN));
- cp += sizeof(u16_t);
- pack32(cp, httl);
- cp += sizeof(u32_t);
- pack16(cp, HTONS(sizeof(u32_t)));
- cp += sizeof(u16_t);
- memcpy(cp, he->h_addr, sizeof(u32_t));
- cp += sizeof(u32_t);
- ancount++;
- break;
- }
- /*FALL THROUGH*/
- case T_CNAME:
- domain= namechr(he->h_name, '.');
- for (i= 0; he->h_aliases[i] != nil; i++) {
- namecpy(name, he->h_aliases[i]);
- if (domain != nil && namechr(name, '.') == nil) {
- namecat(name, domain);
- }
- if (namecmp(qname, name) == 0) {
- r= dn_comp(name, cp, arraylimit(dns.data) - cp,
- dnvec, arraylimit(dnvec));
- if (r == -1) break;
- cp += r;
- if (cp + 3 * sizeof(u16_t)
- + 1 * sizeof(u32_t) > arraylimit(dns.data)) return 0;
- pack16(cp, HTONS(T_CNAME));
- cp += sizeof(u16_t);
- pack16(cp, HTONS(C_IN));
- cp += sizeof(u16_t);
- pack32(cp, httl);
- cp += sizeof(u32_t);
- /* pack16(cp, htonl(RDLENGTH)) */
- cp += sizeof(u16_t);
- r= dn_comp((u8_t *) he->h_name, cp,
- arraylimit(dns.data) - cp,
- dnvec, arraylimit(dnvec));
- if (r == -1) break;
- pack16(cp - sizeof(u16_t), htons(r));
- cp += r;
- ancount++;
- if (type == HTONS(T_A)) goto addA; /* really wants A */
- break;
- }
- }
- break;
- case T_PTR:
- if (ancount > 0) break;
- if (he->h_name[0] == '%') break;
- sprintf((char *) name, "%d.%d.%d.%d.in-addr.arpa",
- ((u8_t *) he->h_addr)[3],
- ((u8_t *) he->h_addr)[2],
- ((u8_t *) he->h_addr)[1],
- ((u8_t *) he->h_addr)[0]);
- if (namecmp(qname, name) == 0) {
- r= dn_comp(name, cp, arraylimit(dns.data) - cp,
- dnvec, arraylimit(dnvec));
- if (r == -1) break;
- cp += r;
- if (cp + 3 * sizeof(u16_t) + 1 * sizeof(u32_t)
- > arraylimit(dns.data)) { r= -1; break; }
- pack16(cp, HTONS(T_PTR));
- cp += sizeof(u16_t);
- pack16(cp, HTONS(C_IN));
- cp += sizeof(u16_t);
- pack32(cp, httl);
- cp += sizeof(u32_t);
- /* pack16(cp, htonl(RDLENGTH)) */
- cp += sizeof(u16_t);
- r= dn_comp((u8_t *) he->h_name, cp,
- arraylimit(dns.data) - cp, dnvec, arraylimit(dnvec));
- if (r == -1) return 0;
- pack16(cp - sizeof(u16_t), htons(r));
- cp += r;
- ancount++;
- }
- break;
- }
- } while (r != -1 && (he= gethostent()) != nil);
- endhostent();
-
- if (r == -1 || ancount == 0) return 0;
-
- dns.hdr.ancount= htons(ancount);
- memcpy(dp, &dns, *pdlen= cp - dns2oct(&dns));
- return 1;
-}
-
-static int query_chaos(u8_t *qname, unsigned type, dns_t *dp, size_t *pdlen)
-/* Report my version. Can't let BIND take all the credit. :-) */
-{
- int i, n, r;
- dns_t dns;
- u8_t *cp;
- u8_t *dnvec[40];
-
- if (type != HTONS(T_TXT) || namecmp(qname, "version.bind") != 0) return 0;
-
- dns.hdr.qr = 1;
- dns.hdr.opcode = 0;
- dns.hdr.aa = 1;
- dns.hdr.tc = 0;
- dns.hdr.rd = 0;
- dns.hdr.ra = 1;
- dns.hdr.unused = 0;
- dns.hdr.ad = 0;
- dns.hdr.cd = 0;
- dns.hdr.rcode = 0;
- dns.hdr.qdcount= HTONS(1);
- dns.hdr.ancount= HTONS(1);
- dns.hdr.nscount= HTONS(0);
- dns.hdr.arcount= htons(n_nameds);
-
- dnvec[0]= dns2oct(&dns);
- dnvec[1]= nil;
- cp= dns.data;
- r= dn_comp(qname, cp, arraysize(dns.data), dnvec, arraylimit(dnvec));
- if (r == -1) return 0;
- cp += r;
- pack16(cp, type);
- cp += sizeof(u16_t);
- pack16(cp, HTONS(C_CHAOS));
- cp += sizeof(u16_t);
-
- r= dn_comp(qname, cp, arraylimit(dns.data) - cp, dnvec, arraylimit(dnvec));
- if (r == -1) return 0;
- cp += r;
- pack16(cp, HTONS(T_TXT));
- cp += sizeof(u16_t);
- pack16(cp, HTONS(C_CHAOS));
- cp += sizeof(u16_t);
- pack32(cp, HTONL(0));
- cp += sizeof(u32_t);
- /* pack16(cp, htonl(RDLENGTH)) */
- cp += sizeof(u16_t);
- sprintf((char *) cp + 1, "nonamed %s at %s:%u",
- version, my_ntoa(my_ip), ntohs(my_port));
- r= strlen((char *) cp + 1) + 1;
- pack16(cp - sizeof(u16_t), htons(r));
- *cp= r-1;
- cp += r;
- for (n= 0, i= i_named; n < n_nameds; n++, i= (i+1) % n_nameds) {
- r= dn_comp((u8_t *) "%nameserver", cp, arraylimit(dns.data) - cp,
- dnvec, arraylimit(dnvec));
- if (r == -1) return 0;
- cp += r;
- if (cp + 3 * sizeof(u16_t)
- + 2 * sizeof(u32_t) > arraylimit(dns.data)) return 0;
- pack16(cp, HTONS(T_A));
- cp += sizeof(u16_t);
- pack16(cp, HTONS(C_IN));
- cp += sizeof(u16_t);
- pack32(cp, HTONL(0));
- cp += sizeof(u32_t);
- pack16(cp, HTONS(sizeof(u32_t)));
- cp += sizeof(u16_t);
- memcpy(cp, &named[i], sizeof(u32_t));
- cp += sizeof(u32_t);
- }
-
- memcpy(dp, &dns, *pdlen= cp - dns2oct(&dns));
- return 1;
-}
-
-static void cache_reply(dns_t *dp, size_t dlen)
-/* Store a DNS packet in the cache. */
-{
- int r;
- query_t *qp, *less, *more;
- unsigned usage;
- u16_t type;
- u8_t *cp;
- u8_t name[MAXDNAME];
- u32_t minttl;
-
- if ((dp->hdr.rd && !dp->hdr.tc)) return;
- if (dp->hdr.qdcount != HTONS(1)) return;
- cp= dp->data;
- r= dn_expand(dns2oct(dp), dns2oct(dp) + dlen, cp, name, MAXDNAME);
- if (r == -1) return;
- cp += r;
- type= upack16(cp);
- cp += sizeof(u16_t);
- if (upack16(cp) != HTONS(C_IN)) return;
-
- /* Delete old cached data, if any. Note where it is in the LRU. */
- if ((qp= get_query(name, type)) != nil) {
- less= qp->less;
- more= qp->more;
- usage= qp->usage;
- deallocate(qp);
- } else {
- /* Not yet in the cache. */
- less= mru;
- more= nil;
- usage= 1;
- }
-
- /* Determine minimum TTL. Discard if zero, never cache zero TTLs. */
- if ((minttl= dns_ttl(dp, dlen, 0)) == 0) return;
-
- /* Enter new reply in cache. */
- qp= allocate(nil, query_allocsize(dlen));
- qp->less= less;
- qp->more= more;
- qp->age= now;
- qp->flags= 0;
- qp->usage= usage;
- qp->size= dlen;
- memcpy(&qp->dns, dp, dlen);
- qp->stale= qp->age + minttl;
- insert_query(qp);
- if (debug >= 1) printf("Answer cached\n");
-
- /* Save the cache soon. */
- if (!dirty) {
- dirty= 1;
- newjob(job_save_cache, now + LONG_TIMEOUT, nil);
- }
-}
-
-static int job_save_cache(void *data, int expired)
-/* Some time after the cache is changed it is written back to disk. */
-{
- if (!expired) return 0;
- cache2file();
- dirty= 0;
- return 1;
-}
-
-static int compose_reply(dns_t *dp, size_t *pdlen)
-/* Try to compose a reply to a request in *dp using the hosts file or
- * cached data. Return answer in *dp with its size in *pdlen. Return true
- * iff an answer is given.
- */
-{
- size_t dlen= *pdlen;
- int r, rd;
- query_t *qp;
- unsigned id, type, class;
- u8_t *cp;
- u8_t name[MAXDNAME];
-
- cp= dp->data;
- r= dn_expand(dns2oct(dp), dns2oct(dp) + dlen, cp, name, MAXDNAME);
- if (r != -1) {
- cp += r;
- if (cp + 2 * sizeof(u16_t) > dns2oct(dp) + dlen) {
- r= -1;
- } else {
- type= upack16(cp);
- cp += sizeof(u16_t);
- class= upack16(cp);
- cp += sizeof(u16_t);
- }
- }
-
- /* Remember ID and RD. */
- id= dp->hdr.id;
- rd= dp->hdr.rd;
-
- if (r == -1) {
- /* Malformed query, reply "FORMERR". */
- dp->hdr.tc = 0;
- dp->hdr.qr = 1;
- dp->hdr.aa = 1;
- dp->hdr.unused = 0;
- dp->hdr.ra = 1;
- dp->hdr.rcode = FORMERR;
- } else
- if (class == HTONS(C_IN) && query_hosts(name, type, dp, pdlen)) {
- /* Answer to this query is in the hosts file. */
- dlen= *pdlen;
- } else
- if (class == HTONS(C_IN) && (qp= get_query(name, type)) != nil) {
- /* Answer to this query is present in the cache. */
- memcpy(dp, &qp->dns, dlen= qp->size);
- dp->hdr.aa = 1;
- (void) dns_ttl(dp, dlen, now - qp->age);
- if (rd) {
- if (qp->stale <= now) {
- qp->flags |= QF_REFRESH;
- q_refresh= 1;
- }
- qp->usage++;
- }
- put_query(qp);
- } else
- if (class == HTONS(C_CHAOS) && query_chaos(name, type, dp, pdlen)) {
- /* Return our version numbers. */
- dlen= *pdlen;
- } else
- if (n_nameds == 0 || nxdomain(name)) {
- /* No real name daemon present, or this name has a repeated top level
- * domain sequence. Reply "no such domain".
- */
- dp->hdr.tc = 0;
- dp->hdr.qr = 1;
- dp->hdr.aa = 1;
- dp->hdr.unused = 0;
- dp->hdr.ra = 1;
- dp->hdr.rcode = NXDOMAIN;
- } else
- if (!rd) {
- /* "Recursion Desired" is off, so don't bother to relay. */
- dp->hdr.tc = 0;
- dp->hdr.qr = 1;
- dp->hdr.unused = 0;
- dp->hdr.ra = 1;
- dp->hdr.rcode = NOERROR;
- } else {
- /* Caller needs to consult with a real name daemon. */
- return 0;
- }
-
- /* Copy ID and RD back to answer. */
- dp->hdr.id= id;
- dp->hdr.rd = rd;
- *pdlen= dlen;
- return 1;
-}
-
-typedef struct udp_dns { /* One DNS packet over UDP. */
- udp_io_hdr_t hdr; /* UDP header (source/destination). */
- dns_t dns; /* DNS packet. */
-} udp_dns_t;
-
-static void refresh_cache(void)
-/* Find a stale entry in the cache that was used to answer a query, and send
- * a request to a name server that should refresh this entry.
- */
-{
- query_t *qp;
- unsigned type;
- int r;
- u8_t *cp;
- size_t dlen, ulen;
- u8_t qname[MAXDNAME+1];
- u8_t *dnvec[40];
- udp_dns_t udp;
-
- if (!q_refresh) return;
- for (qp= lru; qp != nil; qp= qp->more) {
- if ((qp->flags & QF_REFRESH) && qp->stale > now - stale) break;
- }
- if (qp == nil) {
- q_refresh= 0;
- return;
- }
-
- /* Found one to refresh. */
- qp->flags &= ~QF_REFRESH;
- r= dn_expand(dns2oct(&qp->dns), dns2oct(&qp->dns) + qp->size,
- qp->dns.data, qname, MAXDNAME);
- if (r == -1) return;
- type= upack16(qp->dns.data+r);
-
- dnvec[0]= dns2oct(&udp.dns);
- dnvec[1]= nil;
- cp= udp.dns.data;
- r= dn_comp(qname, cp, arraysize(udp.dns.data), dnvec, arraylimit(dnvec));
- if (r == -1) return;
- cp += r;
- pack16(cp, type);
- cp += sizeof(u16_t);
- pack16(cp, HTONS(C_IN));
- cp += sizeof(u16_t);
- dlen= cp - dns2oct(&udp.dns);
-
- udp.dns.hdr.id= new_id(ID_REFRESH, my_port, ID_IPSELF);
- udp.dns.hdr.qr = 0;
- udp.dns.hdr.opcode = 0;
- udp.dns.hdr.aa = 0;
- udp.dns.hdr.tc = 0;
- udp.dns.hdr.rd = 1;
-
- udp.dns.hdr.ra = 0;
- udp.dns.hdr.unused = 0;
- udp.dns.hdr.ad = 0;
- udp.dns.hdr.cd = 0;
- udp.dns.hdr.rcode = 0;
- udp.dns.hdr.qdcount= HTONS(1);
- udp.dns.hdr.ancount= HTONS(0);
- udp.dns.hdr.nscount= HTONS(0);
- udp.dns.hdr.arcount= HTONS(0);
-
- udp.hdr.uih_dst_addr= current_named();
- udp.hdr.uih_dst_port= named_port;
- udp.hdr.uih_ip_opt_len= 0;
- udp.hdr.uih_data_len= dlen;
-
- if (debug >= 1) {
- printf("Refresh to %s:%u:\n",
- my_ntoa(current_named()), ntohs(named_port));
- dns_tell(0, &udp.dns, dlen);
- }
- ulen= offsetof(udp_dns_t, dns) + dlen;
- if (write(udp_fd, &udp, ulen) < 0) fatal(udp_device);
-}
-
-static int job_read_udp(void *data, int expired)
-/* Read UDP queries and replies. */
-{
- ssize_t ulen;
- size_t dlen;
- static udp_dns_t udp;
- u16_t id, port;
- ipaddr_t ip;
- time_t dtime;
-
- assert(!expired);
-
- /* Try to read a packet. */
- ulen= asyn_read(&asyn, udp_fd, &udp, sizeof(udp));
- dlen= ulen - offsetof(udp_dns_t, dns);
-
- if (ulen == -1) {
- if (errno == EINPROGRESS && !expired) return 0;
- if (errno == EIO) fatal(udp_device);
-
- if (debug >= 2) {
- printf("%s: UDP read: %s\n", nowgmt(), strerror(errno));
- }
- } else {
- if (debug >= 2) {
- printf("%s: UDP read, %d bytes\n", nowgmt(), (int) ulen);
- }
- }
-
- /* Restart this job no matter what. */
- newjob(job_read_udp, NEVER, nil);
-
- if (ulen < (ssize_t) (sizeof(udp_io_hdr_t) + sizeof(HEADER))) return 1;
-
- if (debug >= 1) {
- printf("%s:%u UDP ", my_ntoa(udp.hdr.uih_src_addr),
- ntohs(udp.hdr.uih_src_port));
- dns_tell(0, &udp.dns, dlen);
- }
-
- /* Check, and if necessary reinitialize my configuration. */
- init_config(udp.hdr.uih_dst_addr);
-
- if (udp.dns.hdr.qr) {
- /* This is a remote named reply, not a query. */
-
- /* Response to a query previously relayed? */
- if (!old_id(udp.dns.hdr.id, &id, &port, &ip)) return 1;
-
- if (ip == ID_IPSELF && id == ID_PROBE) {
- if (searching()) {
- /* We have found a name server! */
- int i;
-
- /* In my list? */
- for (i= 0; i < n_nameds; i++) {
- if (named[i] == udp.hdr.uih_src_addr) {
- i_named= i;
- if (debug >= 1) {
- printf("Current named = %s\n",
- my_ntoa(current_named()));
- }
- stop_searching();
- force_expire(job_find_named);
- }
- }
- }
- }
-
- /* We got an answer, so stop worrying. */
- if (expecting()) {
- stop_expecting();
- force_expire(job_expect_named);
- }
-
- /* Put the information in the cache. */
- cache_reply(&udp.dns, dlen);
-
- /* Refresh a cached entry that was used when stale. */
- refresh_cache();
-
- /* Discard reply to myself. */
- if (ip == ID_IPSELF) return 1;
-
- /* Send the reply to the process that asked for it. */
- udp.dns.hdr.id= id;
- udp.hdr.uih_dst_addr= ip;
- udp.hdr.uih_dst_port= port;
- if (debug >= 1) printf("To client %s:%u\n", my_ntoa(ip), ntohs(port));
- } else {
- /* A query. */
- if (udp.dns.hdr.qdcount != HTONS(1)) return 1;
-
- if(localonly) {
- /* Check if it's a local query. */
- if(ntohl(udp.hdr.uih_src_addr) != LOCALHOST) {
- syslog(LOG_WARNING, "nonamed: dropped query from %s",
- my_ntoa(udp.hdr.uih_src_addr));
- return 1;
- }
- }
-
- /* Try to compose a reply from local data. */
- if (compose_reply(&udp.dns, &dlen)) {
- udp.hdr.uih_dst_addr= udp.hdr.uih_src_addr;
- udp.hdr.uih_dst_port= udp.hdr.uih_src_port;
- udp.hdr.uih_ip_opt_len= 0;
- udp.hdr.uih_data_len= dlen;
- ulen= offsetof(udp_dns_t, dns) + dlen;
-
- /* Send an UDP DNS reply. */
- if (debug >= 1) {
- printf("%s:%u UDP ", my_ntoa(udp.hdr.uih_dst_addr),
- ntohs(udp.hdr.uih_dst_port));
- dns_tell(0, &udp.dns, dlen);
- }
- } else {
- /* Let a real name daemon handle the query. */
- udp.dns.hdr.id= new_id(udp.dns.hdr.id,
- udp.hdr.uih_src_port, udp.hdr.uih_src_addr);
- udp.hdr.uih_dst_addr= current_named();
- udp.hdr.uih_dst_port= named_port;
- if (!expecting()) {
- start_expecting();
- newjob(job_expect_named, now + MEDIUM_TIMEOUT, nil);
- }
- if (debug >= 1) {
- printf("To named %s:%u\n",
- my_ntoa(current_named()), ntohs(named_port));
- }
- }
- }
- if (write(udp_fd, &udp, ulen) < 0) fatal(udp_device);
- return 1;
-}
-
-#if DO_TCP
-
-typedef struct data_cl { /* Data for connect or listen jobs. */
- int fd; /* Open TCP channel. */
- int dn_fd; /* TCP channel to the name daemon. */
- int retry; /* Retrying a connect? */
- nwio_tcpcl_t tcpcl; /* Flags. */
-} data_cl_t;
-
-typedef struct data_rw { /* Data for TCP read or write jobs. */
- int r_fd; /* Read from this TCP channel. */
- int w_fd; /* And write to this TCP channel. */
- struct data_rw *rev; /* Optional reverse TCP channel. */
- u8_t *buf; /* Buffer for bytes to transfer. */
- ssize_t offset; /* Offset in buf to r/w at. */
- size_t size; /* Size of buf. */
-} data_rw_t;
-
-static int job_setup_listen(void *data, int expired)
-/* Set up a listening channel for TCP DNS queries. */
-{
- data_cl_t *data_cl= data;
- nwio_tcpconf_t tcpconf;
- nwio_tcpopt_t tcpopt;
- int fd;
-
- if (!expired) return 0;
- if (debug >= 2) printf("%s: Setup listen\n", nowgmt());
-
- if (data_cl == nil) {
- if ((fd= open(tcp_device, O_RDWR)) < 0) {
- if (errno != EMFILE) report(tcp_device);
- newjob(job_setup_listen, now + SHORT_TIMEOUT, nil);
- return 1;
- }
-
- tcpconf.nwtc_flags= NWTC_SHARED | NWTC_LP_SET | NWTC_UNSET_RA
- | NWTC_UNSET_RP;
- tcpconf.nwtc_locport= my_port;
- if (ioctl(fd, NWIOSTCPCONF, &tcpconf) == -1) fatal(tcp_device);
-
- tcpopt.nwto_flags= NWTO_DEL_RST;
- if (ioctl(fd, NWIOSTCPOPT, &tcpopt) == -1) fatal(tcp_device);
-
- data_cl= allocate(nil, sizeof(*data_cl));
- data_cl->fd= fd;
- data_cl->tcpcl.nwtcl_flags= 0;
- }
- /* And listen. */
- newjob(job_listen, NEVER, data_cl);
- return 1;
-}
-
-static int job_listen(void *data, int expired)
-/* A connection on the TCP DNS query channel. */
-{
- data_cl_t *data_cl= data;
-
- /* Wait for a client. */
- if (asyn_ioctl(&asyn, data_cl->fd, NWIOTCPLISTEN, &data_cl->tcpcl) < 0) {
- if (errno == EINPROGRESS) return 0;
- report(tcp_device);
-
- /* Try again after a short time. */
- newjob(job_setup_listen, now + SHORT_TIMEOUT, data_cl);
- return 1;
- }
- if (debug >= 2) printf("%s: Listen\n", nowgmt());
-
- /* Immediately resume listening. */
- newjob(job_setup_listen, IMMEDIATE, nil);
-
- /* Set up a connect to the real name daemon. */
- data_cl->retry= 0;
- newjob(job_setup_connect, IMMEDIATE, data_cl);
- return 1;
-}
-
-static void start_relay(int fd, int dn_fd)
-/* Start one or two read jobs after job_setup_connect() or job_connect(). */
-{
- data_rw_t *query; /* Client to DNS daemon relay. */
- data_rw_t *reply; /* DNS daemon to client relay. */
-
- query= allocate(nil, sizeof(*query));
- query->r_fd= fd;
- query->buf= allocate(nil, sizeof(u16_t));
- query->offset= 0;
- query->size= sizeof(u16_t);
- if (dn_fd == NO_FD) {
- /* Answer mode. */
- query->w_fd= fd;
- query->rev= nil;
- } else {
- /* Relay mode. */
- reply= allocate(nil, sizeof(*reply));
- reply->r_fd= dn_fd;
- reply->w_fd= fd;
- reply->buf= allocate(nil, sizeof(u16_t));
- reply->offset= 0;
- reply->size= sizeof(u16_t);
- reply->rev= query;
- query->w_fd= dn_fd;
- query->rev= reply;
- newjob(job_read_reply, now + LONG_TIMEOUT, reply);
- }
- newjob(job_read_query, now + LONG_TIMEOUT, query);
-}
-
-static void close_relay(data_rw_t *data_rw)
-/* Close a relay channel. */
-{
- if (data_rw->rev != nil) {
- /* Other end still active, signal EOF. */
- (void) ioctl(data_rw->w_fd, NWIOTCPSHUTDOWN, nil);
- data_rw->rev->rev= nil;
- } else {
- /* Close both ends down. */
- asyn_close(&asyn, data_rw->r_fd);
- close(data_rw->r_fd);
- if (data_rw->w_fd != data_rw->r_fd) {
- asyn_close(&asyn, data_rw->w_fd);
- close(data_rw->w_fd);
- }
- }
- deallocate(data_rw->buf);
- deallocate(data_rw);
-}
-
-static int job_setup_connect(void *data, int expired)
-/* Set up a connect for a TCP channel to the real name daemon. */
-{
- nwio_tcpconf_t tcpconf;
- int dn_fd;
- data_cl_t *data_cl= data;
-
- if (!expired) return 0;
- if (debug >= 2) printf("%s: Setup connect\n", nowgmt());
-
- if (n_nameds == 0) {
- /* No name daemons to relay to, answer myself. */
- start_relay(data_cl->fd, NO_FD);
- deallocate(data_cl);
- return 1;
- }
-
- if ((dn_fd= open(tcp_device, O_RDWR)) < 0) {
- if (errno != EMFILE) report(tcp_device);
- if (++data_cl->retry < 5) {
- /* Retry. */
- newjob(job_setup_connect, now + SHORT_TIMEOUT, data_cl);
- } else {
- /* Reply myself (bound to fail). */
- start_relay(data_cl->fd, NO_FD);
- deallocate(data_cl);
- }
- return 1;
- }
-
- tcpconf.nwtc_flags= NWTC_LP_SEL | NWTC_SET_RA | NWTC_SET_RP;
- tcpconf.nwtc_remaddr= current_named();
- tcpconf.nwtc_remport= named_port;
- if (ioctl(dn_fd, NWIOSTCPCONF, &tcpconf) == -1) fatal(tcp_device);
-
- /* And connect. */
- data_cl->dn_fd= dn_fd;
- data_cl->tcpcl.nwtcl_flags= 0;
- newjob(job_connect, NEVER, data_cl);
- return 1;
-}
-
-static int job_connect(void *data, int expired)
-/* Connect to a TCP DNS query channel. */
-{
- data_cl_t *data_cl= data;
-
- /* Try to connect. */
- if (asyn_ioctl(&asyn, data_cl->dn_fd, NWIOTCPCONN, &data_cl->tcpcl) < 0) {
- if (errno == EINPROGRESS) return 0;
- if (errno == EIO) fatal(tcp_device);
-
- /* Connection refused. */
- if (debug >= 2) printf("%s: Connect: %s\n", nowgmt(), strerror(errno));
- asyn_close(&asyn, data_cl->dn_fd);
- close(data_cl->dn_fd);
- data_cl->dn_fd= NO_FD;
- if (++data_cl->retry < 5) {
- /* Search a new name daemon. */
- if (!searching()) {
- start_searching();
- force_expire(job_find_named);
- }
- newjob(job_setup_connect, NEVER, data_cl);
- return 1;
- }
- /* Reply with a failure eventually. */
- }
- if (debug >= 2) printf("%s: Connect\n", nowgmt());
-
- /* Read the query from the user, send on to the name daemon, etc. */
- start_relay(data_cl->fd, data_cl->dn_fd);
- deallocate(data_cl);
- return 1;
-}
-
-static void tcp_dns_tell(int fd, u8_t *buf)
-/* Tell about a DNS packet on a TCP channel. */
-{
- nwio_tcpconf_t tcpconf;
-
- if (ioctl(fd, NWIOGTCPCONF, &tcpconf) < 0) {
- printf("??\?:?? TCP ");
- } else {
- printf("%s:%u TCP ", my_ntoa(tcpconf.nwtc_remaddr),
- ntohs(tcpconf.nwtc_remport));
- }
- dns_tell(0, oct2dns(buf + sizeof(u16_t)), ntohs(upack16(buf)));
-}
-
-static int job_read_query(void *data, int expired)
-/* Read TCP queries from the client. */
-{
- data_rw_t *data_rw= data;
- ssize_t count;
-
- /* Try to read count bytes. */
- count= asyn_read(&asyn, data_rw->r_fd,
- data_rw->buf + data_rw->offset,
- data_rw->size - data_rw->offset);
-
- if (count < 0) {
- if (errno == EINPROGRESS && !expired) return 0;
- if (errno == EIO) fatal(tcp_device);
-
- /* Remote end is late, or an error occurred. */
- if (debug >= 2) {
- printf("%s: TCP read query: %s\n", nowgmt(), strerror(errno));
- }
- close_relay(data_rw);
- return 1;
- }
-
- if (debug >= 2) {
- printf("%s: TCP read query, %d/%u bytes\n",
- nowgmt(), data_rw->offset + count, data_rw->size);
- }
- if (count == 0) {
- /* EOF. */
- close_relay(data_rw);
- return 1;
- }
- data_rw->offset += count;
- if (data_rw->offset == data_rw->size) {
- data_rw->size= sizeof(u16_t) + ntohs(upack16(data_rw->buf));
- if (data_rw->size < sizeof(u16_t)) {
- /* Malformed. */
- close_relay(data_rw);
- return 1;
- }
- if (data_rw->offset < data_rw->size) {
- /* Query not complete, read more. */
- data_rw->buf= allocate(data_rw->buf, data_rw->size);
- newjob(job_read_query, now + LONG_TIMEOUT, data_rw);
- return 1;
- }
- }
-
- if (data_rw->size < sizeof(u16_t) + sizeof(dns_hdr_t)) {
- close_relay(data_rw);
- return 1;
- }
- if (debug >= 1) tcp_dns_tell(data_rw->r_fd, data_rw->buf);
-
- /* Relay or reply. */
- if (data_rw->w_fd != data_rw->r_fd) {
- /* We have a real name daemon to do the work. */
- data_rw->offset= 0;
- newjob(job_write_query, now + LONG_TIMEOUT, data_rw);
- } else {
- /* No real name daemons or none reachable, so use the hosts file. */
- dns_t *dp;
- size_t dlen;
-
- if (data_rw->size < sizeof(u16_t) + PACKETSZ) {
- data_rw->buf= allocate(data_rw->buf, sizeof(u16_t) + PACKETSZ);
- }
-
- /* Build a reply packet. */
- dp= oct2dns(data_rw->buf + sizeof(u16_t));
- dlen= data_rw->size - sizeof(u16_t);
- if (!compose_reply(dp, &dlen)) {
- /* We're told to ask a name daemon, but that won't work. */
- close_relay(data_rw);
- return 1;
- }
-
- /* Start a reply write. */
- pack16(data_rw->buf, htons(dlen));
- data_rw->size= sizeof(u16_t) + dlen;
- data_rw->buf= allocate(data_rw->buf, data_rw->size);
- data_rw->offset= 0;
- newjob(job_write_reply, now + LONG_TIMEOUT, data_rw);
- }
- return 1;
-}
-
-static int job_write_query(void *data, int expired)
-/* Relay a TCP query to the name daemon. */
-{
- data_rw_t *data_rw= data;
- ssize_t count;
-
- /* Try to write count bytes to the name daemon. */
- count= asyn_write(&asyn, data_rw->w_fd,
- data_rw->buf + data_rw->offset,
- data_rw->size - data_rw->offset);
-
- if (count <= 0) {
- if (errno == EINPROGRESS && !expired) return 0;
- if (errno == EIO) fatal(tcp_device);
-
- /* A write expired or failed (usually a broken connection.) */
- if (debug >= 2) {
- printf("%s: TCP write query: %s\n", nowgmt(), strerror(errno));
- }
- close_relay(data_rw);
- return 1;
- }
-
- if (debug >= 2) {
- printf("%s: TCP write query, %d/%u bytes\n",
- nowgmt(), data_rw->offset + count, data_rw->size);
- }
- data_rw->offset += count;
- if (data_rw->offset < data_rw->size) {
- /* Partial write, continue. */
- newjob(job_write_query, now + LONG_TIMEOUT, data_rw);
- return 1;
- }
- if (debug >= 1) tcp_dns_tell(data_rw->w_fd, data_rw->buf);
-
- /* Query fully send on, go read more queries. */
- data_rw->offset= 0;
- data_rw->size= sizeof(u16_t);
- newjob(job_read_query, now + LONG_TIMEOUT, data_rw);
- return 1;
-}
-
-static int job_read_reply(void *data, int expired)
-/* Read a TCP reply from the real name daemon. */
-{
- data_rw_t *data_rw= data;
- ssize_t count;
-
- /* Try to read count bytes. */
- count= asyn_read(&asyn, data_rw->r_fd,
- data_rw->buf + data_rw->offset,
- data_rw->size - data_rw->offset);
-
- if (count < 0) {
- if (errno == EINPROGRESS && !expired) return 0;
- if (errno == EIO) fatal(tcp_device);
-
- /* Remote end is late, or an error occurred. */
- if (debug >= 2) {
- printf("%s: TCP read reply: %s\n", nowgmt(), strerror(errno));
- }
- close_relay(data_rw);
- return 1;
- }
-
- if (debug >= 2) {
- printf("%s: TCP read reply, %d/%u bytes\n",
- nowgmt(), data_rw->offset + count, data_rw->size);
- }
- if (count == 0) {
- /* EOF. */
- close_relay(data_rw);
- return 1;
- }
- data_rw->offset += count;
- if (data_rw->offset == data_rw->size) {
- data_rw->size= sizeof(u16_t) + ntohs(upack16(data_rw->buf));
- if (data_rw->size < sizeof(u16_t)) {
- /* Malformed. */
- close_relay(data_rw);
- return 1;
- }
- if (data_rw->offset < data_rw->size) {
- /* Reply not complete, read more. */
- data_rw->buf= allocate(data_rw->buf, data_rw->size);
- newjob(job_read_reply, now + LONG_TIMEOUT, data_rw);
- return 1;
- }
- }
- if (debug >= 1) tcp_dns_tell(data_rw->r_fd, data_rw->buf);
-
- /* Reply fully read, send it on. */
- data_rw->offset= 0;
- newjob(job_write_reply, now + LONG_TIMEOUT, data_rw);
- return 1;
-}
-
-static int job_write_reply(void *data, int expired)
-/* Send a TCP reply to the client. */
-{
- data_rw_t *data_rw= data;
- ssize_t count;
-
- /* Try to write count bytes to the client. */
- count= asyn_write(&asyn, data_rw->w_fd,
- data_rw->buf + data_rw->offset,
- data_rw->size - data_rw->offset);
-
- if (count <= 0) {
- if (errno == EINPROGRESS && !expired) return 0;
- if (errno == EIO) fatal(tcp_device);
-
- /* A write expired or failed (usually a broken connection.) */
- if (debug >= 2) {
- printf("%s: TCP write reply: %s\n", nowgmt(), strerror(errno));
- }
- close_relay(data_rw);
- return 1;
- }
-
- if (debug >= 2) {
- printf("%s: TCP write reply, %d/%u bytes\n",
- nowgmt(), data_rw->offset + count, data_rw->size);
- }
- data_rw->offset += count;
- if (data_rw->offset < data_rw->size) {
- /* Partial write, continue. */
- newjob(job_write_reply, now + LONG_TIMEOUT, data_rw);
- return 1;
- }
- if (debug >= 1) tcp_dns_tell(data_rw->w_fd, data_rw->buf);
-
- /* Reply fully send on, go read more replies (or queries). */
- data_rw->offset= 0;
- data_rw->size= sizeof(u16_t);
- newjob(data_rw->w_fd != data_rw->r_fd ? job_read_reply : job_read_query,
- now + LONG_TIMEOUT, data_rw);
- return 1;
-}
-#else /* !DO_TCP */
-
-static int job_dummy(void *data, int expired)
-{
- return 1;
-}
-#define job_setup_listen job_dummy
-#define job_setup_connect job_dummy
-#endif /* !DO_TCP */
-
-static void named_probe(ipaddr_t ip)
-/* Send a probe to a name daemon, like 'host -r -t ns . <ip>'. */
-{
- udp_dns_t udp;
-# define dlen (offsetof(dns_t, data) + 5)
-# define ulen (offsetof(udp_dns_t, dns) + dlen)
-
- /* Send a simple DNS query that all name servers can answer easily:
- * "What are the name servers for the root domain?"
- */
- udp.dns.hdr.id= new_id(ID_PROBE, my_port, ID_IPSELF);
- udp.dns.hdr.qr = 0;
- udp.dns.hdr.opcode = 0;
- udp.dns.hdr.aa = 0;
- udp.dns.hdr.tc = 0;
- udp.dns.hdr.rd = 0;
- udp.dns.hdr.ra = 0;
- udp.dns.hdr.unused = 0;
- udp.dns.hdr.ad = 0;
- udp.dns.hdr.cd = 0;
- udp.dns.hdr.rcode = 0;
- udp.dns.hdr.qdcount= HTONS(1);
- udp.dns.hdr.ancount= HTONS(0);
- udp.dns.hdr.nscount= HTONS(0);
- udp.dns.hdr.arcount= HTONS(0);
-
- udp.dns.data[0] = 0; /* Null name. */
- pack16(udp.dns.data+1, HTONS(T_NS));
- pack16(udp.dns.data+3, HTONS(C_IN));
- if (debug >= 1) {
- printf("PROBE %s ", my_ntoa(ip));
- dns_tell(0, &udp.dns, dlen);
- }
-
- udp.hdr.uih_dst_addr= ip;
- udp.hdr.uih_dst_port= named_port;
- udp.hdr.uih_ip_opt_len= 0;
- udp.hdr.uih_data_len= dlen;
-
- if (write(udp_fd, &udp, ulen) < 0) fatal(udp_device);
-#undef dlen
-#undef ulen
-}
-
-static int job_find_named(void *data, int expired)
-/* Look for a real name daemon to answer real DNS queries. */
-{
- if (!expired) return 0;
- if (debug >= 2) printf("%s: Find named\n", nowgmt());
-
- /* New search? */
- if (search_ct < 0) {
- search_ct= n_nameds;
- i_named= -1;
- }
-
- if (--search_ct < 0) {
- /* Forced end of search (named response!), or end of search with
- * nothing found. Search again after a long time.
- */
- newjob(job_find_named,
- (stale > 0 || i_named > 0) ? now + LONG_TIMEOUT : NEVER, nil);
- force_expire(job_setup_connect);
- return 1;
- }
-
- /* Send a named probe. */
- i_named= (i_named+1) % n_nameds;
- named_probe(current_named());
-
- /* Schedule the next call. */
- newjob(job_find_named, now + SHORT_TIMEOUT, nil);
- return 1;
-}
-
-static int job_expect_named(void *data, int expired)
-/* The real name server is expected to answer by now. */
-{
- if (!expired) return 0;
- if (debug >= 2) printf("%s: Expect named\n", nowgmt());
-
- if (expecting() && !searching()) {
- /* No answer yet, start searching. */
- start_searching();
- force_expire(job_find_named);
- }
- return 1;
-}
-
-static void sig_handler(int sig)
-/* A signal forces a search for a real name daemon, etc. */
-{
- switch (sig) {
- case SIGINT:
- case SIGTERM: done= 1; break;
- case SIGHUP: reinit= 1; break;
- case SIGUSR1: debug++; break;
- case SIGUSR2: debug= 0; break;
- }
-}
-
-static void usage(void)
-{
- fprintf(stderr, "Usage: nonamed [-qs] [-d[level]] [-p port]\n");
- exit(1);
-}
-
-int main(int argc, char **argv)
-{
- job_t *job;
- nwio_udpopt_t udpopt;
- int i;
- struct servent *servent;
- struct sigaction sa;
- FILE *fp;
- int quit= 0;
-
- /* Debug output must be line buffered. */
- setvbuf(stdout, nil, _IOLBF, 0);
-
- /* DNS service port number? */
- if ((servent= getservbyname("domain", nil)) == nil) {
- fprintf(stderr, "nonamed: \"domain\": unknown service\n");
- exit(1);
- }
- my_port= servent->s_port;
- named_port= servent->s_port;
-
- i= 1;
- while (i < argc && argv[i][0] == '-') {
- char *opt= argv[i++] + 1, *end;
-
- if (opt[0] == '-' && opt[1] == 0) break;
-
- switch (*opt++) {
- case 'd': /* Debug level. */
- debug= 1;
- if (between('0', *opt, '9')) debug= strtoul(opt, &opt, 10);
- break;
- case 'p': /* Port to listen to (for testing.) */
- if (*opt == 0) {
- if (i == argc) usage();
- opt= argv[i++];
- }
- my_port= htons(strtoul(opt, &end, 0));
- if (opt == end || *end != 0) usage();
- opt= end;
- break;
- case 's':
- single= 1;
- break;
- case 'q': /* Quit after printing cache contents. */
- quit= 1;
- break;
- case 'L':
- localonly= 1;
- break;
- default:
- usage();
- }
- }
- if (i != argc) usage();
-
- if (quit) {
- /* Oops, just having a look at the cache. */
- debug= 2;
- now= time(nil);
- n_datamax= -1;
- file2cache();
- return 0;
- }
-
- /* Don't die on broken pipes, reinitialize on hangup, etc. */
- sa.sa_handler= SIG_IGN;
- sigemptyset(&sa.sa_mask);
- sa.sa_flags= 0;
- sigaction(SIGPIPE, &sa, nil);
- sa.sa_handler= sig_handler;
- sigaction(SIGINT, &sa, nil);
- sigaction(SIGHUP, &sa, nil);
- sigaction(SIGUSR1, &sa, nil);
- sigaction(SIGUSR2, &sa, nil);
- sigaction(SIGTERM, &sa, nil);
-
- /* TCP and UDP device names. */
- if ((tcp_device= getenv("TCP_DEVICE")) == nil) tcp_device= TCP_DEVICE;
- if ((udp_device= getenv("UDP_DEVICE")) == nil) udp_device= UDP_DEVICE;
-
- /* Open an UDP channel for incoming DNS queries. */
- if ((udp_fd= open(udp_device, O_RDWR)) < 0) fatal(udp_device);
-
- udpopt.nwuo_flags= NWUO_EXCL | NWUO_LP_SET | NWUO_EN_LOC | NWUO_DI_BROAD
- | NWUO_RP_ANY | NWUO_RA_ANY | NWUO_RWDATALL | NWUO_DI_IPOPT;
- udpopt.nwuo_locport= my_port;
- if (ioctl(udp_fd, NWIOSUDPOPT, &udpopt) == -1
- || ioctl(udp_fd, NWIOGUDPOPT, &udpopt) == -1
- ) {
- fatal(udp_device);
- }
-
- /* The current time is... */
- now= time(nil);
-
- /* Read configuration and data cached by the previous nonamed. */
- init_config(udpopt.nwuo_locaddr);
- file2cache();
-
- if (!single) {
- /* Save process id. */
- if ((fp= fopen(PIDFILE, "w")) != nil) {
- fprintf(fp, "%u\n", (unsigned) getpid());
- fclose(fp);
- }
- }
-
- /* Jobs that start the ball rolling. */
- newjob(job_read_udp, NEVER, nil);
- newjob(job_setup_listen, IMMEDIATE, nil);
- newjob(job_find_named, IMMEDIATE, nil);
-
- /* Open syslog. */
- openlog("nonamed", LOG_PID, LOG_DAEMON);
-
- while (!done) {
- /* There is always something in the queue. */
- assert(queue != nil);
-
- /* Any expired jobs? */
- while (queue->timeout <= now) {
- (void) execjob(queue, 1);
- assert(queue != nil);
- }
-
- /* Check I/O jobs. */
- for (job= queue; job != nil; job= job->next) {
- if (execjob(job, 0)) break;
- }
-
- if (queue->timeout != IMMEDIATE) {
- struct timeval tv, *tvp;
-
- if (debug >= 2) printf("%s: I/O wait", nowgmt());
-
- if (queue->timeout != NEVER) {
- tv.tv_sec= queue->timeout;
- tv.tv_usec= 0;
- tvp= &tv;
- if (debug >= 2) printf(" (expires %s)\n", timegmt(tv.tv_sec));
- } else {
- tvp= nil;
- if (debug >= 2) fputc('\n', stdout);
- }
- fflush(stdout);
-
- if (asyn_wait(&asyn, 0, tvp) < 0) {
- if (errno != EINTR && errno != EAGAIN) fatal("fwait()");
- }
- now= time(nil);
- }
-
- if (reinit) {
- /* A hangup makes us go back to square one. */
- reinit= 0;
- if (ioctl(udp_fd, NWIOGUDPOPT, &udpopt) == -1) fatal(udp_device);
- init_config(udpopt.nwuo_locaddr);
- start_searching();
- force_expire(job_find_named);
- }
- }
- cache2file();
- (void) unlink(PIDFILE);
- if (debug >= 2) printf("sbrk(0) = %u\n", (unsigned) sbrk(0));
- return 0;
-}