Revert "dns cache per interface iteration 2"

This reverts commit f1464ff95670e6dcc0e12bf9fbbeb4c0346434c9

Change-Id: I3496b9a8cb54614fe3eea016d1391c8a89f3db38

1 files changed, 139 insertions, 10 deletions

diff --git a/libc/netbsd/resolv/res_init.c b/libc/netbsd/resolv/res_init.c
index ff6529944..56a25afb8 100644
--- a/libc/netbsd/resolv/res_init.c
+++ b/libc/netbsd/resolv/res_init.c
@@ -111,6 +111,13 @@ __RCSID("$NetBSD: res_init.c,v 1.8 2006/03/19 03:10:08 christos Exp $");
 /* ensure that sockaddr_in6 and IN6ADDR_ANY_INIT are declared / defined */
 #ifdef ANDROID_CHANGES
 #include "resolv_private.h"
+#define MAX_DNS_PROPERTIES 8
+#define DNS_PROP_NAME_PREFIX "net.dns"
+#define DNS_CHANGE_PROP_NAME "net.dnschange"
+#define DNS_SEARCH_PROP_NAME "net.dns.search"
+static const prop_info *dns_change_prop;
+static int dns_last_change_counter;
+static int _get_dns_change_count();
 #else
 #include <resolv.h>
 #endif
@@ -164,6 +171,41 @@ res_ninit(res_state statp) {
 	return (__res_vinit(statp, 0));
 }
 
+#ifdef ANDROID_CHANGES
+static int load_domain_search_list(res_state statp) {
+	char propvalue[PROP_VALUE_MAX];
+	register char *cp, **pp;
+
+	if(__system_property_get(DNS_SEARCH_PROP_NAME, propvalue) >= 1) {
+		strlcpy(statp->defdname, propvalue, sizeof(statp->defdname));
+		if ((cp = strchr(statp->defdname, '\n')) != NULL)
+			*cp = '\0';
+		cp = statp->defdname;
+		pp = statp->dnsrch;
+		while ( pp < statp->dnsrch + MAXDNSRCH ) {
+			while (*cp == ' ' || *cp == '\t') /* skip leading white space */
+				cp++;
+			if (*cp == '\0')  /* stop if nothing more */
+				break;
+			*pp++ = cp;  /* record this search domain */
+			while (*cp) { /* zero-terminate it */
+				if (*cp == ' ' || *cp == '\t') {
+					*cp++ = '\0';
+					break;
+				}
+				cp++;
+			}
+		}
+		*pp = NULL; /* statp->dnsrch has MAXDNSRCH+1 items */
+		if (pp > statp->dnsrch)
+			return 1;
+	}
+	statp->defdname[0] = '\0';  /* no default domain name on Android */
+	statp->dnsrch[0] = NULL;
+	return 0;
+}
+#endif
+
 /* This function has to be reachable by res_data.c but not publicly. */
 int
 __res_vinit(res_state statp, int preinit) {
@@ -178,6 +220,12 @@ __res_vinit(res_state statp, int preinit) {
 	char *net;
 	int dots;
 	union res_sockaddr_union u[2];
+#ifdef ANDROID_CHANGES
+        pid_t mypid = getpid();
+        int use_proc_props = 0;
+        int found_prop;
+	char dnsProperty[PROP_VALUE_MAX];
+#endif
 
         if ((statp->options & RES_INIT) != 0U)
                 res_ndestroy(statp);
@@ -270,8 +318,74 @@ __res_vinit(res_state statp, int preinit) {
 	if (nserv > 0)
 		statp->nscount = nserv;
 #endif
+#ifdef ANDROID_CHANGES /* READ FROM SYSTEM PROPERTIES */
+	dns_last_change_counter = _get_dns_change_count();
 
-#ifndef ANDROID_CHANGES /* !ANDROID_CHANGES - IGNORE resolv.conf in Android */
+	nserv = 0;
+	for(n = 1; n <= MAX_DNS_PROPERTIES && nserv < MAXNS; n++) {
+		char propname[PROP_NAME_MAX];
+		char propvalue[PROP_VALUE_MAX];
+
+		struct addrinfo hints, *ai;
+		char sbuf[NI_MAXSERV];
+		const size_t minsiz = sizeof(statp->_u._ext.ext->nsaddrs[0]);
+
+		/*
+		 * Check first for process-specific properties, and if those don't
+		 * exist, try the generic properties.
+		 */
+		found_prop = 0;
+		if (n == 1 || use_proc_props) {
+			snprintf(propname, sizeof(propname), "%s%d.%d", DNS_PROP_NAME_PREFIX, n, mypid);
+			if(__system_property_get(propname, propvalue) < 1) {
+				if (use_proc_props) {
+					break;
+				}
+			} else {
+				found_prop = 1;
+				use_proc_props = 1;
+			}
+		}
+		if (!found_prop) {
+			snprintf(propname, sizeof(propname), "%s%d", DNS_PROP_NAME_PREFIX, n);
+			if(__system_property_get(propname, propvalue) < 1) {
+				break;
+			}
+		}
+
+		cp = propvalue;
+
+		while (*cp == ' ' || *cp == '\t')
+			cp++;
+		cp[strcspn(cp, ";# \t\n")] = '\0';
+		if ((*cp != '\0') && (*cp != '\n')) {
+			memset(&hints, 0, sizeof(hints));
+			hints.ai_family = PF_UNSPEC;
+			hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
+			hints.ai_flags = AI_NUMERICHOST;
+			sprintf(sbuf, "%u", NAMESERVER_PORT);
+			if (getaddrinfo(cp, sbuf, &hints, &ai) == 0 &&
+			    (size_t)ai->ai_addrlen <= minsiz) {
+				if (statp->_u._ext.ext != NULL) {
+					memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
+					       ai->ai_addr, ai->ai_addrlen);
+				}
+				if ((size_t)ai->ai_addrlen <=
+				    sizeof(statp->nsaddr_list[nserv])) {
+					memcpy(&statp->nsaddr_list[nserv],
+					       ai->ai_addr, ai->ai_addrlen);
+				} else {
+					statp->nsaddr_list[nserv].sin_family = 0;
+				}
+				freeaddrinfo(ai);
+				nserv++;
+			}
+		}
+	}
+
+	/* Add the domain search list */
+	havesearch = load_domain_search_list(statp);
+#else /* !ANDROID_CHANGES - IGNORE resolv.conf in Android */
 #define	MATCH(line, name) \
 	(!strncmp(line, name, sizeof(name) - 1) && \
 	(line[sizeof(name) - 1] == ' ' || \
@@ -793,17 +907,32 @@ res_getservers(res_state statp, union res_sockaddr_union *set, int cnt) {
 }
 
 #ifdef ANDROID_CHANGES
-void res_setiface(res_state statp, const char* iface)
+static int _get_dns_change_count()
 {
-	if (statp != NULL) {
-		// set interface
-		if (iface && iface[0] != '\0') {
-			int len = sizeof(statp->iface);
-			strncpy(statp->iface, iface, len - 1);
-			statp->iface[len - 1] = '\0';
-		} else {
-			statp->iface[0] = '\0';
+	if (dns_change_prop == NULL) {
+		dns_change_prop = __system_property_find(DNS_CHANGE_PROP_NAME);
+	}
+	if (dns_change_prop != NULL) {
+		char propvalue[PROP_VALUE_MAX];
+		if (__system_property_read(dns_change_prop, NULL, propvalue) >= 1) {
+			return atoi(propvalue);
+		}
+	}
+	return -1;
+}
+
+int res_get_dns_changed()
+{
+	int change_count;
+
+	change_count = _get_dns_change_count();
+	if (change_count != dns_last_change_counter) {
+		if (change_count != -1) {
+			dns_last_change_counter = change_count;
 		}
+		return 1;
+	} else {
+		return 0;
 	}
 }
 #endif /* ANDROID_CHANGES */