* the first porting of oao' scdns to busybox also.
*/
-#include <unistd.h>
-#include <string.h>
-#include <signal.h>
-#include <arpa/inet.h>
-#include <sys/socket.h>
-#include <ctype.h>
#include "busybox.h"
-static char *fileconf = "/etc/dnsd.conf";
+static const char *fileconf = "/etc/dnsd.conf";
#define LOCK_FILE "/var/run/dnsd.lock"
-#define LOG_FILE "/var/log/dnsd.log"
+
+// Must match getopt32 call
+#define OPT_daemon (option_mask32 & 0x10)
+#define OPT_verbose (option_mask32 & 0x20)
+
+//#define DEBUG 1
+#define DEBUG 0
enum {
MAX_HOST_LEN = 16, // longest host name allowed is 15
};
static struct dns_entry *dnsentry = NULL;
-static int daemonmode = 0;
static uint32_t ttl = DEFAULT_TTL;
/*
static void convname(char *a, uint8_t *q)
{
int i = (q[0] == '.') ? 0 : 1;
- for(; i < MAX_HOST_LEN-1 && *q; i++, q++)
+ for (; i < MAX_HOST_LEN-1 && *q; i++, q++)
a[i] = tolower(*q);
a[0] = i - 1;
a[i] = 0;
}
/*
- * Insert length of substrings insetad of dots
+ * Insert length of substrings instead of dots
*/
static void undot(uint8_t * rip)
{
int i = 0, s = 0;
- while(rip[i]) i++;
- for(--i; i >= 0; i--) {
- if(rip[i] == '.') {
+ while (rip[i])
+ i++;
+ for (--i; i >= 0; i--) {
+ if (rip[i] == '.') {
rip[i] = s;
s = 0;
} else s++;
}
}
-/*
- * Append message to log file
- */
-static void log_message(char *filename, char *message)
-{
- FILE *logfile;
- if (!daemonmode)
- return;
- logfile = fopen(filename, "a");
- if (!logfile)
- return;
- fprintf(logfile, "%s\n", message);
- fclose(logfile);
-}
-
/*
* Read one line of hostname/IP from file
* Returns 0 for each valid entry read, -1 at EOF
* Assumes all host names are lower case only
- * Hostnames with more than one label is not handled correctly.
+ * Hostnames with more than one label are not handled correctly.
* Presently the dot is copied into name without
* converting to a length/string substring for that label.
*/
-static int getfileentry(FILE * fp, struct dns_entry *s, int verb)
+static int getfileentry(FILE * fp, struct dns_entry *s)
{
unsigned int a,b,c,d;
- char *r, *name;
+ char *line, *r, *name;
-restart:
- if(!(r = bb_get_line_from_file(fp)))
+ restart:
+ line = r = xmalloc_fgets(fp);
+ if (!r)
return -1;
- while(*r == ' ' || *r == '\t') {
+ while (*r == ' ' || *r == '\t') {
r++;
- if(!*r || *r == '#' || *r == '\n')
+ if (!*r || *r == '#' || *r == '\n') {
+ free(line);
goto restart; /* skipping empty/blank and commented lines */
+ }
}
name = r;
- while(*r != ' ' && *r != '\t')
+ while (*r != ' ' && *r != '\t')
r++;
- *r++ = 0;
- if(sscanf(r,"%u.%u.%u.%u",&a,&b,&c,&d) != 4)
- goto restart; /* skipping wrong lines */
+ *r++ = '\0';
+ if (sscanf(r, "%u.%u.%u.%u", &a, &b, &c, &d) != 4) {
+ free(line);
+ goto restart; /* skipping wrong lines */
+ }
- sprintf(s->ip,"%u.%u.%u.%u",a,b,c,d);
- sprintf(s->rip,".%u.%u.%u.%u",d,c,b,a);
+ sprintf(s->ip, "%u.%u.%u.%u", a, b, c, d);
+ sprintf(s->rip, ".%u.%u.%u.%u", d, c, b, a);
undot((uint8_t*)s->rip);
- convname(s->name,(uint8_t*)name);
+ convname(s->name, (uint8_t*)name);
- if(verb)
- fprintf(stderr,"\tname:%s, ip:%s\n",&(s->name[1]),s->ip);
+ if (OPT_verbose)
+ fprintf(stderr, "\tname:%s, ip:%s\n", &(s->name[1]),s->ip);
- return 0; /* warningkiller */
+ free(line);
+ return 0;
}
/*
* Read hostname/IP records from file
*/
-static void dnsentryinit(int verb)
+static void dnsentryinit(void)
{
FILE *fp;
struct dns_entry *m, *prev;
- prev = dnsentry = NULL;
- fp = bb_xfopen(fileconf, "r");
+ prev = dnsentry = NULL;
+ fp = xfopen(fileconf, "r");
while (1) {
- m = xmalloc(sizeof(struct dns_entry));
-
- m->next = NULL;
- if (getfileentry(fp, m, verb))
+ m = xzalloc(sizeof(*m));
+ /*m->next = NULL;*/
+ if (getfileentry(fp, m))
break;
if (prev == NULL)
fclose(fp);
}
-
-/*
- * Set up UDP socket
- */
-static int listen_socket(char *iface_addr, int listen_port)
-{
- struct sockaddr_in a;
- char msg[100];
- int s;
- int yes = 1;
- s = bb_xsocket(PF_INET, SOCK_DGRAM, 0);
-#ifdef SO_REUSEADDR
- if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (char *)&yes, sizeof(yes)) < 0)
- bb_perror_msg_and_die("setsockopt() failed");
-#endif
- memset(&a, 0, sizeof(a));
- a.sin_port = htons(listen_port);
- a.sin_family = AF_INET;
- if (!inet_aton(iface_addr, &a.sin_addr))
- bb_perror_msg_and_die("bad iface address");
- bb_xbind(s, (struct sockaddr *)&a, sizeof(a));
- listen(s, 50); /* bb_xlisten? */
- sprintf(msg, "accepting UDP packets on addr:port %s:%d\n",
- iface_addr, (int)listen_port);
- log_message(LOG_FILE, msg);
- return s;
-}
-
/*
* Look query up in dns records and return answer if found
* qs is the query string, first byte the string length
struct dns_entry *d=dnsentry;
do {
-#ifdef DEBUG
+#if DEBUG
char *p,*q;
q = (char *)&(qs[1]);
p = &(d->name[1]);
- fprintf(stderr, "\ntest: %d <%s> <%s> %d", strlen(p), p, q, strlen(q));
+ fprintf(stderr, "\n%s: %d/%d p:%s q:%s %d",
+ __FUNCTION__, (int)strlen(p), (int)(d->name[0]),
+ p, q, (int)strlen(q));
#endif
if (type == REQ_A) { /* search by host name */
- for(i = 1; i <= (int)(d->name[0]); i++)
- if(tolower(qs[i]) != d->name[i])
- continue;
-#ifdef DEBUG
- fprintf(stderr, " OK");
+ for (i = 1; i <= (int)(d->name[0]); i++)
+ if (tolower(qs[i]) != d->name[i])
+ break;
+ if (i > (int)(d->name[0])) {
+#if DEBUG
+ fprintf(stderr, " OK");
#endif
- strcpy((char *)as, d->ip);
-#ifdef DEBUG
- fprintf(stderr, " %s ", as);
+ strcpy((char *)as, d->ip);
+#if DEBUG
+ fprintf(stderr, " as:%s\n", as);
#endif
return 0;
- }
- else if (type == REQ_PTR) { /* search by IP-address */
+ }
+ } else
+ if (type == REQ_PTR) { /* search by IP-address */
if (!strncmp((char*)&d->rip[1], (char*)&qs[1], strlen(d->rip)-1)) {
strcpy((char *)as, d->name);
return 0;
}
}
- } while ((d = d->next) != NULL);
+ d = d->next;
+ } while (d);
return -1;
}
/*
* Decode message and generate answer
*/
-#define eret(s) do { fprintf (stderr, "%s\n", s); return -1; } while (0)
+#define eret(s) do { fputs(s, stderr); return -1; } while (0)
static int process_packet(uint8_t * buf)
{
struct dns_head *head;
head = (struct dns_head *)buf;
if (head->nquer == 0)
- eret("no queries");
+ eret("no queries\n");
- if ((head->flags & 0x8000))
- eret("ignoring response packet");
+ if (head->flags & 0x8000)
+ eret("ignoring response packet\n");
from = (void *)&head[1]; // start of query string
- next = answb = from + strlen((char *)&head[1]) + 1 + sizeof(struct dns_prop); // where to append answer block
+ next = answb = from + strlen((char *)from) + 1 + sizeof(struct dns_prop); // where to append answer block
outr.rlen = 0; // may change later
outr.r = NULL;
goto empty_packet;
// We have a standard query
-
- log_message(LOG_FILE, (char *)head);
- lookup_result = table_lookup(type, answstr, (uint8_t*)(&head[1]));
+ bb_info_msg("%s", (char *)from);
+ lookup_result = table_lookup(type, answstr, (uint8_t*)from);
if (lookup_result != 0) {
outr.flags = 3 | 0x0400; //name do not exist and auth
goto empty_packet;
memcpy(next, (void *)answstr, outr.rlen);
next += outr.rlen;
- empty_packet:
+ empty_packet:
flags = ntohs(head->flags);
// clear rcode and RA, set responsebit and our new flags
static void interrupt(int x)
{
unlink(LOCK_FILE);
- write(2, "interrupt exiting\n", 18);
+ bb_error_msg("interrupt, exiting\n");
exit(2);
}
-#define is_daemon() (flags&16)
-#define is_verbose() (flags&32)
-//#define DEBUG 1
-
int dnsd_main(int argc, char **argv)
{
+ char *listen_interface = NULL;
+ char *sttl, *sport;
+ len_and_sockaddr *lsa;
int udps;
uint16_t port = 53;
uint8_t buf[MAX_PACK_LEN];
- unsigned long flags = 0;
- char *listen_interface = "0.0.0.0";
- char *sttl=NULL, *sport=NULL;
-
- if(argc > 1)
- flags = bb_getopt_ulflags(argc, argv, "i:c:t:p:dv", &listen_interface, &fileconf, &sttl, &sport);
- if(sttl)
- if(!(ttl = atol(sttl)))
- bb_show_usage();
- if(sport)
- if(!(port = atol(sport)))
- bb_show_usage();
-
- if(is_verbose()) {
- fprintf(stderr,"listen_interface: %s\n", listen_interface);
- fprintf(stderr,"ttl: %d, port: %d\n", ttl, port);
- fprintf(stderr,"fileconf: %s\n", fileconf);
+
+ getopt32(argc, argv, "i:c:t:p:dv", &listen_interface, &fileconf, &sttl, &sport);
+ //if (option_mask32 & 0x1) // -i
+ //if (option_mask32 & 0x2) // -c
+ if (option_mask32 & 0x4) // -t
+ ttl = xatou_range(sttl, 1, 0xffffffff);
+ if (option_mask32 & 0x8) // -p
+ port = xatou_range(sttl, 1, 0xffff);
+
+ if (OPT_verbose) {
+ bb_info_msg("listen_interface: %s", listen_interface);
+ bb_info_msg("ttl: %d, port: %d", ttl, port);
+ bb_info_msg("fileconf: %s", fileconf);
}
- if(is_daemon())
-#if defined(__uClinux__)
+ if (OPT_daemon) {
+//FIXME: NOMMU will NOT set LOGMODE_SYSLOG!
+#ifdef BB_NOMMU
/* reexec for vfork() do continue parent */
vfork_daemon_rexec(1, 0, argc, argv, "-d");
-#else /* uClinux */
- bb_xdaemon(1, 0);
-#endif /* uClinuvx */
+#else
+ xdaemon(1, 0);
+#endif
+ logmode = LOGMODE_SYSLOG;
+ }
- dnsentryinit(is_verbose());
+ dnsentryinit();
signal(SIGINT, interrupt);
signal(SIGPIPE, SIG_IGN);
signal(SIGURG, SIG_IGN);
#endif
- udps = listen_socket(listen_interface, port);
- if (udps < 0)
- exit(1);
+ lsa = host2sockaddr(listen_interface, port);
+ udps = xsocket(lsa->sa.sa_family, SOCK_DGRAM, 0);
+ xbind(udps, &lsa->sa, lsa->len);
+ // xlisten(udps, 50); - ?!! DGRAM sockets are never listened on I think?
+ bb_info_msg("Accepting UDP packets on %s",
+ xmalloc_sockaddr2dotted(&lsa->sa, lsa->len));
while (1) {
fd_set fdset;
FD_ZERO(&fdset);
FD_SET(udps, &fdset);
// Block until a message arrives
- if((r = select(udps + 1, &fdset, NULL, NULL, NULL)) < 0)
+// FIXME: Fantastic. select'ing on just one fd??
+// Why no just block on it doing recvfrom() ?
+ r = select(udps + 1, &fdset, NULL, NULL, NULL);
+ if (r < 0)
bb_perror_msg_and_die("select error");
- else
- if(r == 0)
+ if (r == 0)
bb_perror_msg_and_die("select spurious return");
- /* Can this test ever be false? */
+ /* Can this test ever be false? - yes */
if (FD_ISSET(udps, &fdset)) {
- struct sockaddr_in from;
- int fromlen = sizeof(from);
- r = recvfrom(udps, buf, sizeof(buf), 0,
- (struct sockaddr *)&from,
- (void *)&fromlen);
- if(is_verbose())
- fprintf(stderr, "\n--- Got UDP ");
- log_message(LOG_FILE, "\n--- Got UDP ");
+ socklen_t fromlen = lsa->len;
+// FIXME: need to get *DEST* address (to which of our addresses
+// this query was directed), and reply from the same address.
+// Or else we can exhibit usual UDP ugliness:
+// [ip1.multihomed.ip2] <= query to ip1 <= peer
+// [ip1.multihomed.ip2] => reply from ip2 => peer (confused)
+ r = recvfrom(udps, buf, sizeof(buf), 0, &lsa->sa, &fromlen);
+ if (OPT_verbose)
+ bb_info_msg("Got UDP packet");
if (r < 12 || r > 512) {
bb_error_msg("invalid packet size");
continue;
}
- if (r > 0) {
- r = process_packet(buf);
- if (r > 0)
- sendto(udps, buf,
- r, 0, (struct sockaddr *)&from,
- fromlen);
- }
- } // end if
- } // end while
- return 0;
+ if (r <= 0)
+ continue;
+ r = process_packet(buf);
+ if (r <= 0)
+ continue;
+ sendto(udps, buf, r, 0, &lsa->sa, fromlen);
+ }
+ }
}
-
-
projects / oweals / busybox.git / blobdiff