Add a netcontext variant of gethostbyaddr
Bug: 34953048
Test: Integration tests pass
Change-Id: Id04830345be56cd7a077981c6e2acfb5568e7a88
diff --git a/libc/dns/net/gethnamaddr.c b/libc/dns/net/gethnamaddr.c
index 75cb2b3..036ad1d 100644
--- a/libc/dns/net/gethnamaddr.c
+++ b/libc/dns/net/gethnamaddr.c
@@ -119,6 +119,14 @@
static const char AskedForGot[] =
"gethostby*.getanswer: asked for \"%s\", got \"%s\"";
+static const struct android_net_context NETCONTEXT_UNSET = {
+ .app_mark = MARK_UNSET,
+ .app_netid = NETID_UNSET,
+ .dns_mark = MARK_UNSET,
+ .dns_netid = NETID_UNSET,
+ .uid = NET_CONTEXT_INVALID_UID
+};
+
#define MAXPACKET (64*1024)
typedef union {
@@ -153,8 +161,8 @@
static struct hostent *gethostbyname_internal(const char *, int, res_state,
struct hostent *, char *, size_t, int *, unsigned, unsigned);
-static struct hostent* android_gethostbyaddrfornet_proxy_internal(const void*, socklen_t,
- int, struct hostent *, char *, size_t, int *, unsigned, unsigned);
+static struct hostent* android_gethostbyaddrfornetcontext_proxy_internal(const void*, socklen_t,
+ int, struct hostent *, char *, size_t, int *, const struct android_net_context *);
static const ns_src default_dns_files[] = {
{ NSSRC_FILES, NS_SUCCESS },
@@ -850,8 +858,8 @@
int gethostbyaddr_r(const void *addr, socklen_t len, int af, struct hostent *hp, char *buf,
size_t buflen, struct hostent **result, int *h_errnop)
{
- *result = android_gethostbyaddrfornet_proxy_internal(addr, len, af, hp, buf, buflen, h_errnop,
- NETID_UNSET, MARK_UNSET);
+ *result = android_gethostbyaddrfornetcontext_proxy_internal(
+ addr, len, af, hp, buf, buflen, h_errnop, &NETCONTEXT_UNSET);
if (!*result && errno == ENOSPC) {
errno = ERANGE;
return ERANGE;
@@ -860,8 +868,9 @@
}
static struct hostent *
-android_gethostbyaddrfornet_real(const void *addr, socklen_t len, int af, struct hostent *hp,
- char *buf, size_t buflen, int *he, unsigned netid, unsigned mark)
+android_gethostbyaddrfornetcontext_real(const void *addr, socklen_t len, int af, struct hostent *hp,
+ char *buf, size_t buflen, int *he,
+ const struct android_net_context *netcontext)
{
const u_char *uaddr = (const u_char *)addr;
socklen_t size;
@@ -913,21 +922,21 @@
info.he = he;
*he = NETDB_INTERNAL;
if (nsdispatch(&info, dtab, NSDB_HOSTS, "gethostbyaddr",
- default_dns_files, uaddr, len, af, netid, mark) != NS_SUCCESS)
+ default_dns_files, uaddr, len, af, netcontext) != NS_SUCCESS)
return NULL;
*he = NETDB_SUCCESS;
return hp;
}
static struct hostent*
-android_gethostbyaddrfornet_proxy_internal(const void* addr, socklen_t len, int af,
+android_gethostbyaddrfornetcontext_proxy_internal(const void* addr, socklen_t len, int af,
struct hostent *hp, char *hbuf, size_t hbuflen, int *he,
- unsigned netid, unsigned mark)
+ const struct android_net_context *netcontext)
{
FILE* proxy = android_open_proxy();
if (proxy == NULL) {
// Either we're not supposed to be using the proxy or the proxy is unavailable.
- return android_gethostbyaddrfornet_real(addr,len, af, hp, hbuf, hbuflen, he, netid, mark);
+ return android_gethostbyaddrfornetcontext_real(addr,len, af, hp, hbuf, hbuflen, he, netcontext);
}
char buf[INET6_ADDRSTRLEN]; //big enough for IPv4 and IPv6
@@ -937,7 +946,7 @@
return NULL;
}
- netid = __netdClientDispatch.netIdForResolv(netid);
+ unsigned netid = __netdClientDispatch.netIdForResolv(netcontext->app_netid);
if (fprintf(proxy, "gethostbyaddr %s %d %d %u",
addrStr, len, af, netid) < 0) {
@@ -1238,15 +1247,14 @@
char *bf;
size_t blen;
struct getnamaddr *info = rv;
- unsigned netid, mark;
+ const struct android_net_context *netcontext;
_DIAGASSERT(rv != NULL);
uaddr = va_arg(ap, unsigned char *);
info->hp->h_length = va_arg(ap, int);
info->hp->h_addrtype = va_arg(ap, int);
- netid = va_arg(ap, unsigned);
- mark = va_arg(ap, unsigned);
+ netcontext = va_arg(ap, const struct android_net_context *);
switch (info->hp->h_addrtype) {
case AF_INET:
@@ -1288,8 +1296,8 @@
free(buf);
return NS_NOTFOUND;
}
- res_setnetid(res, netid);
- res_setmark(res, mark);
+ res_setnetid(res, netcontext->dns_netid);
+ res_setmark(res, netcontext->dns_mark);
n = res_nquery(res, qbuf, C_IN, T_PTR, buf->buf, (int)sizeof(buf->buf));
if (n < 0) {
free(buf);
@@ -1585,6 +1593,21 @@
return result;
}
+// android_gethostby*fornet can be called in two different contexts.
+// - In the proxy client context (proxy != NULL), |netid| is |app_netid|.
+// - In the proxy listener context (proxy == NULL), |netid| is |dns_netid|.
+// The netcontext is constructed before checking which context we are in.
+// Therefore, we have to populate both fields, and rely on the downstream code to check whether
+// |proxy == NULL|, and use that info to query the field that matches the caller's intent.
+static struct android_net_context make_context(unsigned netid, unsigned mark) {
+ struct android_net_context netcontext = NETCONTEXT_UNSET;
+ netcontext.app_netid = netid;
+ netcontext.app_mark = mark;
+ netcontext.dns_netid = netid;
+ netcontext.dns_mark = mark;
+ return netcontext;
+}
+
struct hostent *
android_gethostbynamefornet(const char *name, int af, unsigned netid, unsigned mark)
{
@@ -1602,22 +1625,30 @@
struct hostent *
gethostbyaddr(const void *addr, socklen_t len, int af)
{
- return android_gethostbyaddrfornet_proxy(addr, len, af, NETID_UNSET, MARK_UNSET);
+ return android_gethostbyaddrfornetcontext_proxy(addr, len, af, &NETCONTEXT_UNSET);
}
struct hostent *
android_gethostbyaddrfornet(const void *addr, socklen_t len, int af, unsigned netid, unsigned mark)
{
- return android_gethostbyaddrfornet_proxy(addr, len, af, netid, mark);
+ const struct android_net_context netcontext = make_context(netid, mark);
+ return android_gethostbyaddrfornetcontext(addr, len, af, &netcontext);
+}
+
+struct hostent *
+android_gethostbyaddrfornetcontext(const void *addr, socklen_t len, int af,
+ const struct android_net_context *netcontext)
+{
+ return android_gethostbyaddrfornetcontext_proxy(addr, len, af, netcontext);
}
__LIBC_HIDDEN__ struct hostent*
-android_gethostbyaddrfornet_proxy(const void* addr, socklen_t len, int af,
- unsigned netid, unsigned mark)
+android_gethostbyaddrfornetcontext_proxy(const void* addr, socklen_t len, int af,
+ const struct android_net_context *netcontext)
{
res_static rs = __res_get_static(); /* Use res_static to provide thread-safety. */
- return android_gethostbyaddrfornet_proxy_internal(addr, len, af, &rs->host, rs->hostbuf,
- sizeof(rs->hostbuf), &h_errno, netid, mark);
+ return android_gethostbyaddrfornetcontext_proxy_internal(addr, len, af, &rs->host, rs->hostbuf,
+ sizeof(rs->hostbuf), &h_errno, netcontext);
}
struct hostent *