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authorDenis Vlasenko2007-03-24 12:13:04 +0000
committerDenis Vlasenko2007-03-24 12:13:04 +0000
commitd3bac03988b104998c90dbce50e152668c3e4f5d (patch)
tree3c140f23588b0eff532e7c9c9431ea12daaaaf87 /networking/dnsd.c
parent9067f13be067f39f6c8586926b190b7dee0def3d (diff)
downloadbusybox-d3bac03988b104998c90dbce50e152668c3e4f5d.zip
busybox-d3bac03988b104998c90dbce50e152668c3e4f5d.tar.gz
dnsd: fix several buglets, make smaller
Diffstat (limited to 'networking/dnsd.c')
-rw-r--r--networking/dnsd.c104
1 files changed, 41 insertions, 63 deletions
diff --git a/networking/dnsd.c b/networking/dnsd.c
index fb0c56c..fd2f421 100644
--- a/networking/dnsd.c
+++ b/networking/dnsd.c
@@ -19,13 +19,6 @@
#include "busybox.h"
-static const char *fileconf = "/etc/dnsd.conf";
-#define LOCK_FILE "/var/run/dnsd.lock"
-
-// Must match getopt32 call
-#define OPT_daemon (option_mask32 & 0x10)
-#define OPT_verbose (option_mask32 & 0x20)
-
//#define DEBUG 1
#define DEBUG 0
@@ -75,9 +68,16 @@ struct dns_entry { // element of known name, ip address and reversed ip address
char name[MAX_HOST_LEN];
};
-static struct dns_entry *dnsentry = NULL;
+static struct dns_entry *dnsentry;
static uint32_t ttl = DEFAULT_TTL;
+static const char *fileconf = "/etc/dnsd.conf";
+
+// Must match getopt32 call
+#define OPT_daemon (option_mask32 & 0x10)
+#define OPT_verbose (option_mask32 & 0x20)
+
+
/*
* Convert host name from C-string to dns length/string.
*/
@@ -135,12 +135,12 @@ static int getfileentry(FILE * fp, struct dns_entry *s)
while (*r != ' ' && *r != '\t')
r++;
*r++ = '\0';
- if (sscanf(r, "%u.%u.%u.%u", &a, &b, &c, &d) != 4) {
+ if (sscanf(r, ".%u.%u.%u.%u"+1, &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->ip, ".%u.%u.%u.%u"+1, 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);
@@ -185,7 +185,7 @@ static void dnsentryinit(void)
static int table_lookup(uint16_t type, uint8_t * as, uint8_t * qs)
{
int i;
- struct dns_entry *d=dnsentry;
+ struct dns_entry *d = dnsentry;
do {
#if DEBUG
@@ -201,17 +201,13 @@ static int table_lookup(uint16_t type, uint8_t * as, uint8_t * qs)
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);
#if DEBUG
- fprintf(stderr, " as:%s\n", as);
+ fprintf(stderr, " OK as:%s\n", as);
#endif
- return 0;
+ 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;
@@ -226,7 +222,6 @@ static int table_lookup(uint16_t type, uint8_t * as, uint8_t * qs)
/*
* Decode message and generate answer
*/
-#define eret(s) do { fputs(s, stderr); return -1; } while (0)
static int process_packet(uint8_t * buf)
{
struct dns_head *head;
@@ -241,11 +236,15 @@ static int process_packet(uint8_t * buf)
answstr[0] = '\0';
head = (struct dns_head *)buf;
- if (head->nquer == 0)
- eret("no queries\n");
+ if (head->nquer == 0) {
+ bb_error_msg("no queries");
+ retunr -1;
+ }
- if (head->flags & 0x8000)
- eret("ignoring response packet\n");
+ if (head->flags & 0x8000) {
+ bb_error_msg("ignoring response packet");
+ retunr -1;
+ }
from = (void *)&head[1]; // start of query string
next = answb = from + strlen((char *)from) + 1 + sizeof(struct dns_prop); // where to append answer block
@@ -286,8 +285,7 @@ static int process_packet(uint8_t * buf)
}
memcpy(answstr, &a.s_addr, 4); // save before a disappears
outr.rlen = 4; // uint32_t IP
- }
- else
+ } else
outr.rlen = strlen((char *)answstr) + 1; // a host name
outr.r = answstr; // 32 bit ip or a host name
outr.flags |= 0x0400; /* authority-bit */
@@ -316,7 +314,7 @@ static int process_packet(uint8_t * buf)
head->nauth = head->nadd = htons(0);
head->nquer = htons(1);
- packet_len = next - (void *)buf;
+ packet_len = (uint8_t *)next - buf;
return packet_len;
}
@@ -325,7 +323,7 @@ static int process_packet(uint8_t * buf)
*/
static void interrupt(int x)
{
- unlink(LOCK_FILE);
+ /* unlink("/var/run/dnsd.lock"); */
bb_error_msg("interrupt, exiting\n");
exit(2);
}
@@ -333,7 +331,7 @@ static void interrupt(int x)
int dnsd_main(int argc, char **argv);
int dnsd_main(int argc, char **argv)
{
- char *listen_interface = NULL;
+ const char *listen_interface = "0.0.0.0";
char *sttl, *sport;
len_and_sockaddr *lsa;
int udps;
@@ -346,7 +344,7 @@ int dnsd_main(int argc, char **argv)
if (option_mask32 & 0x4) // -t
ttl = xatou_range(sttl, 1, 0xffffffff);
if (option_mask32 & 0x8) // -p
- port = xatou_range(sttl, 1, 0xffff);
+ port = xatou_range(sport, 1, 0xffff);
if (OPT_verbose) {
bb_info_msg("listen_interface: %s", listen_interface);
@@ -355,7 +353,6 @@ int dnsd_main(int argc, char **argv)
}
if (OPT_daemon) {
-//FIXME: NOMMU will NOT set LOGMODE_SYSLOG!
#ifdef BB_NOMMU
if (!re_execed)
vfork_daemon_rexec(1, 0, argv);
@@ -368,7 +365,7 @@ int dnsd_main(int argc, char **argv)
dnsentryinit();
signal(SIGINT, interrupt);
- signal(SIGPIPE, SIG_IGN);
+ /* why? signal(SIGPIPE, SIG_IGN); */
signal(SIGHUP, SIG_IGN);
#ifdef SIGTSTP
signal(SIGTSTP, SIG_IGN);
@@ -377,50 +374,31 @@ int dnsd_main(int argc, char **argv)
signal(SIGURG, SIG_IGN);
#endif
- lsa = xhost2sockaddr(listen_interface, port);
+ lsa = xdotted2sockaddr(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?
+ /* 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;
int r;
-
- FD_ZERO(&fdset);
- FD_SET(udps, &fdset);
- // Block until a message arrives
-// 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");
- if (r == 0)
- bb_perror_msg_and_die("select spurious return");
-
- /* Can this test ever be false? - yes */
- if (FD_ISSET(udps, &fdset)) {
- socklen_t fromlen = lsa->len;
+ 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)
- continue;
- r = process_packet(buf);
- if (r <= 0)
- continue;
- sendto(udps, buf, r, 0, &lsa->sa, fromlen);
+ 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;
}
+ r = process_packet(buf);
+ if (r <= 0)
+ continue;
+ sendto(udps, buf, r, 0, &lsa->sa, fromlen);
}
}