commit 9bf0e1dfbbaade0c0a32bf2e23e1cb52f5e9cbc0
author Bernie Innocenti <codewiz@google.com> Wed Sep 12 17:59:17 2018 +0900
committer Bernie Innocenti <codewiz@google.com> Wed Sep 12 20:29:08 2018 +0900
tree 0dce9ac42959a830bdbeebbd64e68a5097985d34
parent 583330f788858165426ae89dd8412a1b51ef9985

nsdispatch removal from gethostbyname()

This gets rid of several layers of obfuscation in between nsdispatch()
and the functions which actually lookup for a hostname in the hosts
file and dns.

This opens the way for even more cleanups, which I will leave for
another day; let's first rip off nsdispatch() from everywhere, which
lets us kill another dependency on an internal bionic header.

Test: atest netd_integration_test

Change-Id: I911fb254939ecc9661695d0ca5474c3caeb4c1d9

resolv/gethnamaddr.cpp

diff --git a/resolv/gethnamaddr.cpp b/resolv/gethnamaddr.cpp
index 604f9c1..338f2af 100644
--- a/resolv/gethnamaddr.cpp
+++ b/resolv/gethnamaddr.cpp
@@ -138,15 +138,10 @@
 static void map_v4v6_hostent(struct hostent*, char**, char*);
 static void addrsort(char**, int, res_state);
 
-void ht_sethostent(int);
-void ht_endhostent(void);
 struct hostent* ht_gethostbyname(char*);
 struct hostent* ht_gethostbyaddr(const char*, int, int);
-void dns_service(void);
-#undef dn_skipname
-int dn_skipname(const u_char*, const u_char*);
 static int _dns_gethtbyaddr(void*, void*, va_list);
-static int _dns_gethtbyname(void*, void*, va_list);
+static int _dns_gethtbyname(const char* name, int addr_type, getnamaddr* info);
 
 static struct hostent* gethostbyname_internal(const char*, int, res_state, struct hostent*, char*,
                                               size_t, int*, const struct android_net_context*);
@@ -562,11 +557,6 @@
     struct getnamaddr info;
     char hbuf[MAXHOSTNAMELEN];
     size_t size;
-    static const ns_dtab dtab[] = {
-        {NSSRC_FILES, _hf_gethtbyname,  NULL},
-        {NSSRC_DNS,   _dns_gethtbyname, NULL},
-        {0, 0, 0}
-    };
 
     _DIAGASSERT(name != NULL);
 
@@ -630,9 +620,11 @@
     info.buf = buf;
     info.buflen = buflen;
     info.he = he;
-    if (nsdispatch(&info, dtab, NSDB_HOSTS, "gethostbyname", default_dns_files, name, strlen(name),
-                   af) != NS_SUCCESS)
-        return NULL;
+    if (!_hf_gethtbyname2(name, af, &info)) {
+        if (_dns_gethtbyname(name, af, &info) != NS_SUCCESS) {
+            return NULL;
+        }
+    }
     *he = NETDB_SUCCESS;
     return hp;
 nospc:
@@ -926,18 +918,12 @@
     }
 }
 
-static int _dns_gethtbyname(void* rv, void* /*cb_data*/, va_list ap) {
+static int _dns_gethtbyname(const char* name, int addr_type, getnamaddr* info) {
     int n, type;
     struct hostent* hp;
-    const char* name;
     res_state res;
-    struct getnamaddr* info = (struct getnamaddr*) rv;
 
-    _DIAGASSERT(rv != NULL);
-
-    name = va_arg(ap, char*);
-    /* NOSTRICT skip string len */ (void) va_arg(ap, int);
-    info->hp->h_addrtype = va_arg(ap, int);
+    info->hp->h_addrtype = addr_type;
 
     switch (info->hp->h_addrtype) {
         case AF_INET:
@@ -1156,16 +1142,3 @@
     return android_gethostbyaddrfornetcontext_proxy_internal(
             addr, len, af, &rs->host, rs->hostbuf, sizeof(rs->hostbuf), &h_errno, netcontext);
 }
-
-struct hostent* gethostent(void) {
-    struct res_static* rs = __res_get_static();  // For thread-safety.
-    if (!rs->hostf) {
-        sethostent_r(&rs->hostf);
-        if (!rs->hostf) {
-            h_errno = NETDB_INTERNAL;
-            return NULL;
-        }
-    }
-    memset(&rs->host, 0, sizeof(rs->host));
-    return netbsd_gethostent_r(rs->hostf, &rs->host, rs->hostbuf, sizeof(rs->hostbuf), &h_errno);
-}