libresolv-38.tar.gz

[apple/libresolv.git] / res_query.c

diff --git a/res_query.c b/res_query.c
index 7df8c6c42a36230a12a9fe2992ca953aeb575616..d2e3760ac9958ff56e5c347ed2f6a5e765369bd8 100644 (file)
--- a/res_query.c
+++ b/res_query.c
@@ -94,10 +94,16 @@ static const char rcsid[] = "$Id: res_query.c,v 1.1 2006/03/01 19:01:38 majka Ex
 #include <sys/time.h>
 #include <time.h>
 #include <unistd.h>
 #include <sys/time.h>
 #include <time.h>
 #include <unistd.h>

+#include <notify.h>
+#include <pthread.h>

 #ifndef __APPLE__
 #include "port_after.h"
 #endif
 
 #ifndef __APPLE__
 #include "port_after.h"
 #endif
 

+/* interrupt mechanism is implemented in res_send.c */
+__private_extern__ int interrupt_pipe_enabled;
+__private_extern__ pthread_key_t interrupt_pipe_key;
+

 /* Options.  Leave them on. */
 #define DEBUG
 
 /* Options.  Leave them on. */
 #define DEBUG
 


@@ -135,7 +141,9 @@ struct res_query_context
        u_char *answer;
        size_t anslen;
        size_t ansmaxlen;
        u_char *answer;
        size_t anslen;
        size_t ansmaxlen;

+       uint16_t lastanstype;

        uint32_t ifnum;
        uint32_t ifnum;

+       uint32_t res_flags;

        DNSServiceFlags flags;
        DNSServiceErrorType error;
 };
        DNSServiceFlags flags;
        DNSServiceErrorType error;
 };


@@ -155,10 +163,18 @@ res_query_callback(DNSServiceRef sdRef, DNSServiceFlags flags, uint32_t ifIndex,
        context->flags = flags;
        context->error = errorCode;
 
        context->flags = flags;
        context->error = errorCode;
 

-       if (errorCode != kDNSServiceErr_NoError) return;
+       if (errorCode != kDNSServiceErr_NoError)
+       {
+               if (context->res_flags & RES_DEBUG) printf(";; res_query_mDNSResponder callback [%s %hu %hu]: error %u\n", fullname, rrtype, rrclass, errorCode);
+               return;
+       }

 
        buflen = context->ansmaxlen - context->anslen;
 
        buflen = context->ansmaxlen - context->anslen;

-       if (buflen < NS_HFIXEDSZ) return;
+       if (buflen < NS_HFIXEDSZ)
+       {
+               if (context->res_flags & RES_DEBUG) printf(";; res_query_mDNSResponder callback [%s %hu %hu]: malformed reply\n", fullname, rrtype, rrclass);
+               return;
+       }

 
        dnlist[0] = context->answer + NS_HFIXEDSZ;
        dnlist[1] = NULL;
 
        dnlist[0] = context->answer + NS_HFIXEDSZ;
        dnlist[1] = NULL;


@@ -166,13 +182,23 @@ res_query_callback(DNSServiceRef sdRef, DNSServiceFlags flags, uint32_t ifIndex,
        cp = context->answer + context->anslen;
 
        n = dn_comp((char *)fullname, cp, buflen, dnlist, &dnlist[1]);
        cp = context->answer + context->anslen;
 
        n = dn_comp((char *)fullname, cp, buflen, dnlist, &dnlist[1]);

-       if (n < 0) return;
+       if (n < 0)
+       {
+               if (context->res_flags & RES_DEBUG) printf(";; res_query_mDNSResponder callback [%s %hu %hu]: name mismatch\n", fullname, rrtype, rrclass);
+               return;
+       }

 
        /*
         * Check that there is enough space in the buffer for the resource name (n),
         * the resource record data (rdlen) and the resource record header (10).
         */
 
        /*
         * Check that there is enough space in the buffer for the resource name (n),
         * the resource record data (rdlen) and the resource record header (10).
         */

-       if (buflen < n + rdlen + 10) return;
+       if (buflen < n + rdlen + 10)
+       {
+               if (context->res_flags & RES_DEBUG) printf(";; res_query_mDNSResponder callback [%s %hu %hu]: insufficient buffer space for reply\n", fullname, rrtype, rrclass);
+               return;
+       }
+       
+       if (context->res_flags & RES_DEBUG) printf(";; res_query_mDNSResponder callback for %s %hu %hu\n", fullname, rrtype, rrclass);

 
        cp += n;
        buflen -= n;
 
        cp += n;
        buflen -= n;


@@ -197,6 +223,8 @@ res_query_callback(DNSServiceRef sdRef, DNSServiceFlags flags, uint32_t ifIndex,
 
        context->anslen = (size_t)(cp - context->answer);
 
 
        context->anslen = (size_t)(cp - context->answer);
 

+       context->lastanstype = rrtype;
+

        /* 
         * Save the interface number for the first AAAA record for link-local addresses.
         * It's used by getaddrinfo to set the scope id.
        /* 
         * Save the interface number for the first AAAA record for link-local addresses.
         * It's used by getaddrinfo to set the scope id.


@@ -266,29 +294,34 @@ _is_rev_link_local(const char *name)
        return 1;
 }
 
        return 1;
 }
 

-__private_extern__ int
+int

 res_query_mDNSResponder(res_state statp, const char *name, int class, int type, u_char *answer, int anslen, struct sockaddr *from, uint32_t *fromlen)
 {
        DNSServiceRef sdRef;
        DNSServiceErrorType result;
        struct res_query_context context;
 res_query_mDNSResponder(res_state statp, const char *name, int class, int type, u_char *answer, int anslen, struct sockaddr *from, uint32_t *fromlen)
 {
        DNSServiceRef sdRef;
        DNSServiceErrorType result;
        struct res_query_context context;

-       int i, kq, n, wait;
-       struct kevent kv;
+       int i, kq, n, wait, cancelled, notify_token, status;
+       struct kevent mevent, ievent, event;

        struct timeval ctv;
        struct timespec now, finish, timeout;
        HEADER *ans;
        uint32_t iface;
        uint16_t nibble;
        struct timeval ctv;
        struct timespec now, finish, timeout;
        HEADER *ans;
        uint32_t iface;
        uint16_t nibble;

-       char *qname;
+       char *qname, *notify_name;
+       int *interrupt_pipe;
+       uint64_t exit_requested;
+
+       interrupt_pipe = NULL;

        result = 0;
        kq = -1;
        ans = (HEADER *)answer;
        result = 0;
        kq = -1;
        ans = (HEADER *)answer;

-
+       cancelled = 0;

        ans->rcode = 0;
 
        memset(&context, 0, sizeof(struct res_query_context));
 
        /* Build a dummy DNS header with question for the answer */
        ans->rcode = 0;
 
        memset(&context, 0, sizeof(struct res_query_context));
 
        /* Build a dummy DNS header with question for the answer */

+       context.res_flags = statp->options;

        context.answer = answer;
        context.ansmaxlen = anslen;
        context.anslen = res_nmkquery(statp, ns_o_query, name, class, type, NULL, 0, NULL, answer, anslen);
        context.answer = answer;
        context.ansmaxlen = anslen;
        context.anslen = res_nmkquery(statp, ns_o_query, name, class, type, NULL, 0, NULL, answer, anslen);


@@ -338,6 +371,8 @@ res_query_mDNSResponder(res_state statp, const char *name, int class, int type,
                }
        }
 
                }
        }
 

+       if (statp->options & RES_DEBUG) printf(";; res_query_mDNSResponder\n");
+

        result = DNSServiceQueryRecord(&sdRef, kDNSServiceFlagsReturnIntermediates, iface, qname, type, class, res_query_callback, &context);
        if (iface != 0) free(qname);
 
        result = DNSServiceQueryRecord(&sdRef, kDNSServiceFlagsReturnIntermediates, iface, qname, type, class, res_query_callback, &context);
        if (iface != 0) free(qname);
 


@@ -356,12 +391,59 @@ res_query_mDNSResponder(res_state statp, const char *name, int class, int type,
        finish.tv_sec = ctv.tv_sec + statp->retrans;
        finish.tv_nsec = ctv.tv_usec * 1000;
 
        finish.tv_sec = ctv.tv_sec + statp->retrans;
        finish.tv_nsec = ctv.tv_usec * 1000;
 

-       EV_SET(&kv, DNSServiceRefSockFD(sdRef), EVFILT_READ, EV_ADD | EV_ONESHOT, 0, 0, 0);
+       /* add mdns reply FD to kqueue */
+       EV_SET(&mevent, DNSServiceRefSockFD(sdRef), EVFILT_READ, EV_ADD, 0, 0, 0);
+       n = kevent(kq, &mevent, 1, NULL, 0, NULL);
+       if (n != 0) return 0;
+
+       /* add interrupt pipe to kqueue if interrupt is enabled */
+       if (interrupt_pipe_enabled != 0)
+       {
+               interrupt_pipe = pthread_getspecific(interrupt_pipe_key);
+               if (interrupt_pipe != NULL)
+               {
+                       if (interrupt_pipe[0] >= 0)
+                       {
+                               EV_SET(&ievent, interrupt_pipe[0], EVFILT_READ, EV_ADD, 0, 0, (void *)name);
+                               /* allow this to fail silently (should never happen, but it would only break interrupts */
+                               n = kevent(kq, &ievent, 1, NULL, 0, NULL);
+                       }
+               }
+       }
+
+       /*
+        * Get notification token
+        * we use a self-notification token to allow a caller
+        * to signal the thread doing this DNS query to quit.
+        */
+       notify_name = NULL;
+       notify_token = -1;
+
+       asprintf(&notify_name, "self.thread.%lu", (unsigned long)pthread_self());
+       if (notify_name != NULL) 
+       {
+               status = notify_register_plain(notify_name, &notify_token);
+               free(notify_name);
+       }

 
        wait = 1;
        while (wait == 1)
        {
 
        wait = 1;
        while (wait == 1)
        {

-               n = kevent(kq, &kv, 1, &kv, 1, &timeout);
+               memset(&event, 0, sizeof(struct kevent));
+               n = kevent(kq, NULL, 0, &event, 1, &timeout);
+
+               if (notify_token != -1)
+               {
+                       exit_requested = 0;
+                       status = notify_get_state(notify_token, &exit_requested);
+                       if (exit_requested == ThreadStateExitRequested)
+                       {
+                               /* interrupted */
+                               if (statp->options & RES_DEBUG) printf(";; cancelled\n");
+                               cancelled = 1;
+                               break;
+                       }
+               }

 
                if (n < 0)
                {
 
                if (n < 0)
                {


@@ -374,6 +456,13 @@ res_query_mDNSResponder(res_state statp, const char *name, int class, int type,
                        h_errno = TRY_AGAIN;
                        wait = 0;
                }
                        h_errno = TRY_AGAIN;
                        wait = 0;
                }

+               else if (event.udata == (void *)name)
+               {
+                       /* interrupted */
+                       if (statp->options & RES_DEBUG) printf(";; cancelled\n");
+                       cancelled = 1;
+                       break;
+               }

                else
                {
                        result = DNSServiceProcessResult(sdRef);
                else
                {
                        result = DNSServiceProcessResult(sdRef);


@@ -384,7 +473,7 @@ res_query_mDNSResponder(res_state statp, const char *name, int class, int type,
                                wait = 0;
                        }
 
                                wait = 0;
                        }
 

-                       if ((ans->ancount > 0) && ((context.flags & kDNSServiceFlagsMoreComing) == 0)) wait = 0;
+                       if ((ans->ancount > 0) && ((context.flags & kDNSServiceFlagsMoreComing) == 0) && ((context.lastanstype != ns_t_cname) || (type == ns_t_cname))) wait = 0;

                }
 
        keep_waiting:
                }
 
        keep_waiting:


@@ -410,10 +499,11 @@ res_query_mDNSResponder(res_state statp, const char *name, int class, int type,
                }
        }
 
                }
        }
 

+       if (notify_token != -1) notify_cancel(notify_token);

        DNSServiceRefDeallocate(sdRef);
        close(kq);
 
        DNSServiceRefDeallocate(sdRef);
        close(kq);
 

-       if (ans->ancount == 0) context.anslen = -1;
+       if ((ans->ancount == 0) || (cancelled == 1)) context.anslen = -1;

 
        if ((from != NULL) && (fromlen != NULL) && (context.ifnum != 0))
        {
 
        if ((from != NULL) && (fromlen != NULL) && (context.ifnum != 0))
        {