diff options
| -rw-r--r-- | src/lib/krb5/os/dnsglue.c | 68 |
1 files changed, 45 insertions, 23 deletions
diff --git a/src/lib/krb5/os/dnsglue.c b/src/lib/krb5/os/dnsglue.c index 028d9c536d..c4adbad110 100644 --- a/src/lib/krb5/os/dnsglue.c +++ b/src/lib/krb5/os/dnsglue.c @@ -28,6 +28,9 @@ #ifdef KRB5_DNS_LOOKUP #include "dnsglue.h" +#ifdef __APPLE__ +#include <dns.h> +#endif /* * Only use res_ninit() if there's also a res_ndestroy(), to avoid @@ -37,9 +40,6 @@ * In any case, it is probable that platforms having broken * res_ninit() will have thread safety hacks for res_init() and _res. */ -#if HAVE_RES_NINIT && HAVE_RES_NDESTROY && HAVE_RES_NSEARCH -#define USE_RES_NINIT 1 -#endif /* * Opaque handle @@ -64,6 +64,44 @@ static int initparse(struct krb5int_dns_state *); #endif /* + * Define macros to use the best available DNS search functions. INIT_HANDLE() + * returns true if handle initialization is successful, false if it is not. + * SEARCH() returns the length of the response or -1 on error. + * DECLARE_HANDLE() must be used last in the declaration list since it may + * evaluate to nothing. + */ + +#if defined(__APPLE__) + +/* Use the OS X interfaces dns_open, dns_search, and dns_free. */ +#define DECLARE_HANDLE(h) dns_handle_t h +#define INIT_HANDLE(h) ((h = dns_open(NULL)) != NULL) +#define SEARCH(h, n, c, t, a, l) dns_search(h, n, c, t, a, l, NULL, NULL) +#define DESTROY_HANDLE(h) dns_free(h) + +#elif HAVE_RES_NINIT && HAVE_RES_NSEARCH + +/* Use res_ninit, res_nsearch, and res_ndestroy or res_nclose. */ +#define DECLARE_HANDLE(h) struct __res_state h +#define INIT_HANDLE(h) (memset(&h, 0, sizeof(h)), res_ninit(&h) == 0) +#define SEARCH(h, n, c, t, a, l) res_nsearch(&h, n, c, t, a, l) +#if HAVE_RES_NDESTROY +#define DESTROY_HANDLE(h) res_ndestroy(&h) +#else +#define DESTROY_HANDLE(h) res_nclose(&h) +#endif + +#else + +/* Use res_init and res_search. */ +#define DECLARE_HANDLE(h) +#define INIT_HANDLE(h) (res_init() == 0) +#define SEARCH(h, n, c, t, a, l) res_search(n, c, t, a, l) +#define DESTROY_HANDLE(h) + +#endif + +/* * krb5int_dns_init() * * Initialize an opaque handle. Do name lookup and initial parsing of @@ -74,13 +112,11 @@ int krb5int_dns_init(struct krb5int_dns_state **dsp, char *host, int nclass, int ntype) { -#if USE_RES_NINIT - struct __res_state statbuf; -#endif struct krb5int_dns_state *ds; int len, ret; size_t nextincr, maxincr; unsigned char *p; + DECLARE_HANDLE(h); *dsp = ds = malloc(sizeof(*ds)); if (ds == NULL) @@ -99,13 +135,7 @@ krb5int_dns_init(struct krb5int_dns_state **dsp, ds->cur_ans = 0; #endif -#if USE_RES_NINIT - memset(&statbuf, 0, sizeof(statbuf)); - ret = res_ninit(&statbuf); -#else - ret = res_init(); -#endif - if (ret < 0) + if (!INIT_HANDLE(h)) return -1; do { @@ -119,13 +149,7 @@ krb5int_dns_init(struct krb5int_dns_state **dsp, ds->ansp = p; ds->ansmax = nextincr; -#if USE_RES_NINIT - len = res_nsearch(&statbuf, host, ds->nclass, ds->ntype, - ds->ansp, ds->ansmax); -#else - len = res_search(host, ds->nclass, ds->ntype, - ds->ansp, ds->ansmax); -#endif + len = SEARCH(h, host, ds->nclass, ds->ntype, ds->ansp, ds->ansmax); if ((size_t) len > maxincr) { ret = -1; goto errout; @@ -150,9 +174,7 @@ krb5int_dns_init(struct krb5int_dns_state **dsp, ret = 0; errout: -#if USE_RES_NINIT - res_ndestroy(&statbuf); -#endif + DESTROY_HANDLE(h); if (ret < 0) { if (ds->ansp != NULL) { free(ds->ansp); |