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-rw-r--r--include/resolv.h33
-rw-r--r--libc/inet/resolv.c162
2 files changed, 140 insertions, 55 deletions
diff --git a/include/resolv.h b/include/resolv.h
index 6651dded9..d5168770d 100644
--- a/include/resolv.h
+++ b/include/resolv.h
@@ -118,10 +118,9 @@ struct __res_state {
int retry; /* number of times to retransmit */
#endif
u_int32_t options; /* (was: ulong) option flags - see below. */
- struct sockaddr_in
- nsaddr_list[MAXNS]; /* address of name server */
+ struct sockaddr_in nsaddr_list[MAXNS]; /* address of name server */
#define nsaddr nsaddr_list[0] /* for backward compatibility */
- char *dnsrch[MAXDNSRCH+1]; /* components of domain to search */
+ char *dnsrch[MAXDNSRCH + 1]; /* components of domain to search */
#ifdef __UCLIBC_HAS_COMPAT_RES_STATE__
/* googling for "_res.defdname" says it's still sometimes used.
* Pity. It's huge, I want to move it to EXTRA_COMPAT... */
@@ -138,18 +137,38 @@ struct __res_state {
struct in_addr addr;
u_int32_t mask;
} sort_list[MAXRESOLVSORT];
+#endif
+
+#ifdef __UCLIBC_HAS_IPV6__
+ /* I assume that the intention is to store all
+ * DNS servers' addresses here, and duplicate in nsaddr_list[]
+ * those which have IPv4 address. In the case of IPv4 address
+ * _u._ext.nsaddrs[x] will point to some nsaddr_list[y],
+ * otherwise it will point into malloc'ed sockaddr_in6.
+ * nscount is the number of IPv4 addresses and _u._ext.nscount
+ * is the number of addresses of all kinds.
+ *
+ * If this differs from established usage and you need
+ * to change this, please describe how is it supposed to work.
+ */
union {
struct {
- u_int16_t nscount;
- u_int16_t nstimes[MAXNS]; /* ms. */
+ struct sockaddr_in6 *nsaddrs[MAXNS];
+ u_int8_t nscount; /* (was: u_int16_t) */
+#ifdef __UCLIBC_HAS_COMPAT_RES_STATE__
+ /* rather obscure, and differs in BSD and glibc */
+ u_int16_t nstimes[MAXNS];
int nssocks[MAXNS];
- /* below: not in xBSD. glibc only? */
u_int16_t nscount6;
u_int16_t nsinit;
- struct sockaddr_in6 *nsaddrs[MAXNS];
+ /* glibc also has: */
+ /*u_int16_t nsmap[MAXNS];*/
+ /*unsigned long long initstamp;*/
+#endif
} _ext;
} _u;
#endif
+
#ifdef __UCLIBC_HAS_EXTRA_COMPAT_RES_STATE__
/* Truly obscure stuff.
* Googling for "_res.XXX" for these members
diff --git a/libc/inet/resolv.c b/libc/inet/resolv.c
index defd4d77c..4a1f97541 100644
--- a/libc/inet/resolv.c
+++ b/libc/inet/resolv.c
@@ -241,6 +241,9 @@ libc_hidden_proto(__libc_getdomainname)
#define DPRINTF(X,args...)
#endif /* DEBUG */
+#undef ARRAY_SIZE
+#define ARRAY_SIZE(v) (sizeof(v) / sizeof((v)[0]))
+
/* Make sure the incoming char * buffer is aligned enough to handle our random
* structures. This define is the same as we use for malloc alignment (which
* has same requirements). The offset is the number of bytes we need to adjust
@@ -305,6 +308,11 @@ extern unsigned __nameservers attribute_hidden;
extern unsigned __searchdomains attribute_hidden;
extern sockaddr46_t *__nameserver attribute_hidden;
extern char **__searchdomain attribute_hidden;
+#ifdef __UCLIBC_HAS_IPV4__
+extern const struct sockaddr_in __local_nameserver attribute_hidden;
+#else
+extern const struct sockaddr_in6 __local_nameserver attribute_hidden;
+#endif
/* Arbitrary */
#define MAXLEN_searchdomain 128
@@ -858,6 +866,12 @@ int __form_query(int id, const char *name, int type, unsigned char *packet,
#ifdef L_opennameservers
+# if __BYTE_ORDER == __LITTLE_ENDIAN
+#define NAMESERVER_PORT_N (__bswap_constant_16(NAMESERVER_PORT))
+#else
+#define NAMESERVER_PORT_N NAMESERVER_PORT
+#endif
+
__UCLIBC_MUTEX_INIT(__resolv_lock, PTHREAD_MUTEX_INITIALIZER);
/* Protected by __resolv_lock */
@@ -867,6 +881,17 @@ unsigned __nameservers;
unsigned __searchdomains;
sockaddr46_t *__nameserver;
char **__searchdomain;
+#ifdef __UCLIBC_HAS_IPV4__
+const struct sockaddr_in __local_nameserver = {
+ .sin_family = AF_INET,
+ .sin_port = NAMESERVER_PORT_N,
+};
+#else
+const struct sockaddr_in6 __local_nameserver = {
+ .sin6_family = AF_INET6,
+ .sin6_port = NAMESERVER_PORT_N,
+};
+#endif
/* Helpers. Both stop on EOL, if it's '\n', it is converted to NUL first */
static char *skip_nospace(char *p)
@@ -954,30 +979,28 @@ void attribute_hidden __open_nameservers(void)
}
if (strcmp(keyword, "domain") == 0 || strcmp(keyword, "search") == 0) {
char *p1;
-//TODO: delete old domains...
+
+ /* free old domains ("last 'domain' or 'search' wins" rule) */
+ while (__searchdomains)
+ free(__searchdomain[--__searchdomains]);
+ /*free(__searchdomain);*/
+ /*__searchdomain = NULL; - not necessary */
next_word:
/* terminate current word */
p1 = skip_nospace(p);
/* find next word (maybe) */
p1 = skip_and_NUL_space(p1);
- /* paranoia - done by having szBuffer[MAXLEN_searchdomain] */
- /*if (strlen(p) > MAXLEN_searchdomain)*/
- /* goto skip;*/
- /* do we have this domain already? */
- for (i = 0; i < __searchdomains; i++)
- if (strcmp(p, __searchdomain[i]) == 0)
- goto skip;
/* add it */
ptr = realloc(__searchdomain, (__searchdomains + 1) * sizeof(__searchdomain[0]));
if (!ptr)
continue;
__searchdomain = ptr;
+ /* NB: strlen(p) <= MAXLEN_searchdomain) because szBuffer[] is smaller */
ptr = strdup(p);
if (!ptr)
continue;
DPRINTF("adding search %s\n", (char*)ptr);
__searchdomain[__searchdomains++] = (char*)ptr;
- skip:
p = p1;
if (*p)
goto next_word;
@@ -989,17 +1012,7 @@ void attribute_hidden __open_nameservers(void)
fclose(fp);
}
if (__nameservers == 0) {
- __nameserver = malloc(sizeof(__nameserver[0]));
-//TODO: error check?
- memset(&__nameserver[0], 0, sizeof(__nameserver[0]));
-#ifdef __UCLIBC_HAS_IPV4__
- __nameserver[0].sa4.sin_family = AF_INET;
- /*__nameserver[0].sa4.sin_addr = INADDR_ANY; - done by memset */
- __nameserver[0].sa4.sin_port = htons(NAMESERVER_PORT);
-#else
- __nameserver[0].sa6.sin6_family = AF_INET6;
- __nameserver[0].sa6.sin6_port = htons(NAMESERVER_PORT);
-#endif
+ __nameserver = (void*) &__local_nameserver;
__nameservers++;
}
if (__searchdomains == 0) {
@@ -1009,10 +1022,16 @@ void attribute_hidden __open_nameservers(void)
buf[sizeof(buf) - 1] = '\0';
if (i == 0 && (p = strchr(buf, '.')) != NULL && p[1]) {
p = strdup(p + 1);
+ if (!p)
+ goto err;
__searchdomain = malloc(sizeof(__searchdomain[0]));
-//TODO: error check?
+ if (!__searchdomain) {
+ free(p);
+ goto err;
+ }
__searchdomain[0] = p;
__searchdomains++;
+ err: ;
}
}
DPRINTF("nameservers = %d\n", __nameservers);
@@ -1029,7 +1048,8 @@ void attribute_hidden __open_nameservers(void)
/* Must be called under __resolv_lock. */
void attribute_hidden __close_nameservers(void)
{
- free(__nameserver);
+ if (__nameserver != (void*) &__local_nameserver)
+ free(__nameserver);
__nameserver = NULL;
__nameservers = 0;
while (__searchdomains)
@@ -1383,7 +1403,7 @@ libc_hidden_def(gethostbyname)
struct hostent *gethostbyname2(const char *name, int family)
{
#ifndef __UCLIBC_HAS_IPV6__
- return family == AF_INET ? gethostbyname(name) : (struct hostent*)0;
+ return family == AF_INET ? gethostbyname(name) : (struct hostent*)NULL;
#else /* __UCLIBC_HAS_IPV6__ */
static struct hostent h;
static char buf[sizeof(struct in6_addr) +
@@ -1404,30 +1424,27 @@ struct hostent *gethostbyname2(const char *name, int family)
/* Protected by __resolv_lock */
struct __res_state _res;
-#undef ARRAY_SIZE
-#define ARRAY_SIZE(v) (sizeof(v) / sizeof((v)[0]))
-
/* Will be called under __resolv_lock. */
static void res_sync_func(void)
{
struct __res_state *rp = &(_res);
+ int n;
- /* Track .nscount and .nsaddr_list
- * (busybox's nslookup uses it).
- */
- if (__nameservers > rp->nscount)
- __nameservers = rp->nscount;
/* TODO:
* if (__nameservers < rp->nscount) - try to grow __nameserver[]?
*/
-#ifdef __UCLIBC_HAS_IPV4__
- {
- int n = __nameservers;
- while (--n >= 0) {
- __nameserver[n].sa.sa_family = AF_INET;
- __nameserver[n].sa4 = rp->nsaddr_list[n]; /* struct copy */
- }
- }
+#ifdef __UCLIBC_HAS_IPV6__
+ if (__nameservers > rp->_u._ext.nscount)
+ __nameservers = rp->_u._ext.nscount;
+ n = __nameservers;
+ while (--n >= 0)
+ __nameserver[n].sa6 = *rp->_u._ext.nsaddrs[n]; /* struct copy */
+#else /* __UCLIBC_HAS_IPV4__ */
+ if (__nameservers > rp->nscount)
+ __nameservers = rp->nscount;
+ n = __nameservers;
+ while (--n >= 0)
+ __nameserver[n].sa4 = rp->nsaddr_list[n]; /* struct copy */
#endif
/* Extend and comment what program is known
* to use which _res.XXX member(s).
@@ -1439,8 +1456,12 @@ static void res_sync_func(void)
/* Our res_init never fails (always returns 0) */
int res_init(void)
{
- int i, n;
struct __res_state *rp = &(_res);
+ int i;
+ int n;
+#ifdef __UCLIBC_HAS_IPV6__
+ int m = 0;
+#endif
__UCLIBC_MUTEX_LOCK(__resolv_lock);
__close_nameservers();
@@ -1465,23 +1486,57 @@ int res_init(void)
n = ARRAY_SIZE(rp->dnsrch);
for (i = 0; i < n; i++)
rp->dnsrch[i] = __searchdomain[i];
-#ifdef __UCLIBC_HAS_IPV4__
+
+ /* copy nameservers' addresses */
i = 0;
+#ifdef __UCLIBC_HAS_IPV4__
n = 0;
while (n < ARRAY_SIZE(rp->nsaddr_list) && i < __nameservers) {
- if (__nameserver[i].sa.sa_family != AF_INET)
- goto next_i;
- rp->nsaddr_list[n] = __nameserver[i].sa4; /* struct copy */
- n++;
- next_i:
+ if (__nameserver[i].sa.sa_family == AF_INET) {
+ rp->nsaddr_list[n] = __nameserver[i].sa4; /* struct copy */
+#ifdef __UCLIBC_HAS_IPV6__
+ if (m < ARRAY_SIZE(rp->_u._ext.nsaddrs)) {
+ rp->_u._ext.nsaddrs[m] = (void*) &rp->nsaddr_list[n];
+ m++;
+ }
+#endif
+ n++;
+ }
+#ifdef __UCLIBC_HAS_IPV6__
+ if (__nameserver[i].sa.sa_family == AF_INET6
+ && m < ARRAY_SIZE(rp->_u._ext.nsaddrs)
+ ) {
+ struct sockaddr_in6 *sa6 = malloc(sizeof(sa6));
+ if (sa6) {
+ *sa6 = __nameserver[i].sa6; /* struct copy */
+ rp->_u._ext.nsaddrs[m] = sa6;
+ m++;
+ }
+ }
+#endif
i++;
}
rp->nscount = n;
+#ifdef __UCLIBC_HAS_IPV6__
+ rp->_u._ext.nscount = m;
#endif
+
+#else /* if !__UCLIBC_HAS_IPV4__ (only IPV6) */
+ while (m < ARRAY_SIZE(rp->_u._ext.nsaddrs) && i < __nameservers) {
+ struct sockaddr_in6 *sa6 = malloc(sizeof(sa6));
+ if (sa6) {
+ *sa6 = __nameserver[i].sa6; /* struct copy */
+ rp->_u._ext.nsaddrs[m] = sa6;
+ m++;
+ }
+ i++;
+ }
+ rp->_u._ext.nscount = m;
+#endif /* !__UCLIBC_HAS_IPV4__ (only IPV6) */
+
__UCLIBC_MUTEX_UNLOCK(__resolv_lock);
return 0;
}
-#undef ARRAY_SIZE
libc_hidden_def(res_init)
#ifdef __UCLIBC_HAS_BSD_RES_CLOSE__
@@ -1490,6 +1545,18 @@ void res_close(void)
__UCLIBC_MUTEX_LOCK(__resolv_lock);
__close_nameservers();
__res_sync = NULL;
+#ifdef __UCLIBC_HAS_IPV6__
+ {
+ char *p1 = (char*) &(_res.nsaddr_list[0]);
+ int m = 0;
+ /* free nsaddrs[m] if they do not point to nsaddr_list[x] */
+ while (m < ARRAY_SIZE(_res._u._ext.nsaddrs)) {
+ char *p2 = (char*)(_res._u._ext.nsaddrs[m]);
+ if (p2 < p1 || (p2 - p1) > sizeof(_res.nsaddr_list))
+ free(p2);
+ }
+ }
+#endif
memset(&_res, 0, sizeof(_res));
__UCLIBC_MUTEX_UNLOCK(__resolv_lock);
}
@@ -1497,7 +1564,6 @@ void res_close(void)
#endif /* L_res_init */
-
#ifdef L_res_query
int res_query(const char *dname, int class, int type,
generated by cgit v1.2.3 (git 2.46.0) at 2025-11-04 01:43:00 +0000