Proxy getnameinfo through netd
Proxy the parts of getnameinfo that utilize
the dns cache through netd.
Change-Id: I1d57c451ea6b179c34828cf57a4182b262674003
diff --git a/libc/netbsd/net/getnameinfo.c b/libc/netbsd/net/getnameinfo.c
index 3666443..0b9fe51 100644
--- a/libc/netbsd/net/getnameinfo.c
+++ b/libc/netbsd/net/getnameinfo.c
@@ -64,6 +64,11 @@
#include <netdb.h>
#ifdef ANDROID_CHANGES
#include "resolv_private.h"
+#include <sys/system_properties.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/un.h>
+#include <errno.h>
#else
#include <resolv.h>
#endif
@@ -124,7 +129,93 @@
}
}
+#ifdef ANDROID_CHANGES
+/* On success length of the host name is returned. A return
+ * value of 0 means there's no host name associated with
+ * the address. On failure -1 is returned in which case
+ * normal execution flow shall continue. */
+static int
+android_gethostbyaddr_proxy(struct hostent* hp, const char *addr, socklen_t addrLen, int addrFamily) {
+ int sock;
+ const int one = 1;
+ struct sockaddr_un proxy_addr;
+ const char* cache_mode = getenv("ANDROID_DNS_MODE");
+ FILE* proxy = NULL;
+ int result = -1;
+
+ if (cache_mode != NULL && strcmp(cache_mode, "local") == 0) {
+ // Don't use the proxy in local mode. This is used by the
+ // proxy itself.
+ return -1;
+ }
+
+ // Temporary cautious hack to disable the DNS proxy for processes
+ // requesting special treatment. Ideally the DNS proxy should
+ // accomodate these apps, though.
+ char propname[PROP_NAME_MAX];
+ char propvalue[PROP_VALUE_MAX];
+ snprintf(propname, sizeof(propname), "net.dns1.%d", getpid());
+ if (__system_property_get(propname, propvalue) > 0) {
+ return -1;
+ }
+ // create socket
+ sock = socket(AF_UNIX, SOCK_STREAM, 0);
+ if (sock < 0) {
+ return -1;
+ }
+
+ setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
+ memset(&proxy_addr, 0, sizeof(proxy_addr));
+ proxy_addr.sun_family = AF_UNIX;
+ strlcpy(proxy_addr.sun_path, "/dev/socket/dnsproxyd",
+ sizeof(proxy_addr.sun_path));
+ if (TEMP_FAILURE_RETRY(connect(sock, (const struct sockaddr*) &proxy_addr,
+ sizeof(proxy_addr))) != 0) {
+ close(sock);
+ return -1;
+ }
+
+ // send request to DnsProxyListener
+ proxy = fdopen(sock,"r+");
+ if (proxy == NULL) {
+ goto exit;
+ }
+
+ if (fprintf(proxy, "gethostbyaddr %s %d %d", addr, addrLen, addrFamily) < 0) {
+ goto exit;
+ }
+
+ // literal NULL byte at end, required by FrameworkListener
+ if (fputc(0, proxy) == EOF || fflush(proxy) != 0) {
+ goto exit;
+ }
+
+ result = 0;
+ uint32_t name_len;
+ if (fread(&name_len, sizeof(name_len), 1, proxy) != 1) {
+ goto exit;
+ }
+
+ name_len = ntohl(name_len);
+ if (name_len <= 0) {
+ goto exit;
+ }
+
+ if (fread(hp->h_name, name_len, 1, proxy) != 1) {
+ goto exit;
+ }
+
+ result = name_len;
+
+ exit:
+ if (proxy != NULL) {
+ fclose(proxy);
+ }
+
+ return result;
+}
+#endif
/*
* getnameinfo_inet():
* Format an IPv4 or IPv6 sockaddr into a printable string.
@@ -277,7 +368,21 @@
break;
}
} else {
+#ifdef ANDROID_CHANGES
+ struct hostent android_proxy_hostent;
+ char android_proxy_buf[MAXDNAME];
+ android_proxy_hostent.h_name = android_proxy_buf;
+
+ int hostnamelen = android_gethostbyaddr_proxy(&android_proxy_hostent,
+ addr, afd->a_addrlen, afd->a_af);
+ if (hostnamelen >= 0) {
+ hp = (hostnamelen > 0) ? &android_proxy_hostent : NULL;
+ } else {
+ hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
+ }
+#else
hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
+#endif
if (hp) {
#if 0