From fe3c993ae7176553c7691fcac82aa6c961c86259 Mon Sep 17 00:00:00 2001
From: Valentin Gosu <valentin.gosu@gmail.com>
Date: Tue, 22 Oct 2019 19:46:28 +0000
Subject: [PATCH] Bug 1588219 - Expose DNS suffix list (Linux) r=dragana

Differential Revision: https://phabricator.services.mozilla.com/D49414

--HG--
extra : moz-landing-system : lando
---
 netwerk/system/linux/nsNetworkLinkService.cpp |  7 +++-
 netwerk/system/netlink/NetlinkService.cpp     | 37 +++++++++++++++++++
 netwerk/system/netlink/NetlinkService.h       |  3 ++
 3 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/netwerk/system/linux/nsNetworkLinkService.cpp b/netwerk/system/linux/nsNetworkLinkService.cpp
index d9ca40a0382c..74b86a280bd9 100644
--- a/netwerk/system/linux/nsNetworkLinkService.cpp
+++ b/netwerk/system/linux/nsNetworkLinkService.cpp
@@ -60,7 +60,12 @@ nsNetworkLinkService::GetNetworkID(nsACString& aNetworkID) {
 
 NS_IMETHODIMP
 nsNetworkLinkService::GetDnsSuffixList(nsTArray<nsCString>& aDnsSuffixList) {
-  return NS_ERROR_NOT_IMPLEMENTED;
+  if (!mNetlinkSvc) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  mNetlinkSvc->GetDnsSuffixList(aDnsSuffixList);
+  return NS_OK;
 }
 
 NS_IMETHODIMP
diff --git a/netwerk/system/netlink/NetlinkService.cpp b/netwerk/system/netlink/NetlinkService.cpp
index 84ee38d65e92..a91dad6a8f7c 100644
--- a/netwerk/system/netlink/NetlinkService.cpp
+++ b/netwerk/system/netlink/NetlinkService.cpp
@@ -26,6 +26,12 @@
 #include "mozilla/Telemetry.h"
 #include "mozilla/DebugOnly.h"
 
+#if defined(HAVE_RES_NINIT)
+#  include <netinet/in.h>
+#  include <arpa/nameser.h>
+#  include <resolv.h>
+#endif
+
 /* a shorter name that better explains what it does */
 #define EINTR_RETRY(x) MOZ_TEMP_FAILURE_RETRY(x)
 
@@ -1711,6 +1717,26 @@ bool NetlinkService::CalculateIDForFamily(uint8_t aFamily, SHA1Sum* aSHA1) {
   return retval;
 }
 
+void NetlinkService::ComputeDNSSuffixList() {
+  MOZ_ASSERT(!NS_IsMainThread(), "Must not be called on the main thread");
+#if defined(HAVE_RES_NINIT)
+  nsTArray<nsCString> suffixList;
+  struct __res_state res;
+  if (res_ninit(&res) == 0) {
+    for (int i = 0; i < MAXDNSRCH; i++) {
+      if (!res.dnsrch[i]) {
+        break;
+      }
+      suffixList.AppendElement(nsCString(res.dnsrch[i]));
+    }
+    res_nclose(&res);
+  }
+
+  MutexAutoLock lock(mMutex);
+  mDNSSuffixList = std::move(suffixList);
+#endif
+}
+
 // Figure out the "network identification".
 void NetlinkService::CalculateNetworkID() {
   LOG(("NetlinkService::CalculateNetworkID"));
@@ -1723,6 +1749,7 @@ void NetlinkService::CalculateNetworkID() {
   SHA1Sum sha1;
 
   UpdateLinkStatus();
+  ComputeDNSSuffixList();
 
   bool idChanged = false;
   bool found4 = CalculateIDForFamily(AF_INET, &sha1);
@@ -1793,6 +1820,16 @@ void NetlinkService::GetNetworkID(nsACString& aNetworkID) {
   aNetworkID = mNetworkId;
 }
 
+nsresult NetlinkService::GetDnsSuffixList(nsTArray<nsCString>& aDnsSuffixList) {
+#if defined(HAVE_RES_NINIT)
+  MutexAutoLock lock(mMutex);
+  aDnsSuffixList = mDNSSuffixList;
+  return NS_OK;
+#else
+  return NS_ERROR_NOT_IMPLEMENTED;
+#endif
+}
+
 void NetlinkService::GetIsLinkUp(bool* aIsUp) {
   MutexAutoLock lock(mMutex);
   *aIsUp = mLinkUp;
diff --git a/netwerk/system/netlink/NetlinkService.h b/netwerk/system/netlink/NetlinkService.h
index 0344761c913a..4d3929db7d18 100644
--- a/netwerk/system/netlink/NetlinkService.h
+++ b/netwerk/system/netlink/NetlinkService.h
@@ -55,6 +55,7 @@ class NetlinkService : public nsIRunnable {
   nsresult Shutdown();
   void GetNetworkID(nsACString& aNetworkID);
   void GetIsLinkUp(bool* aIsUp);
+  nsresult GetDnsSuffixList(nsTArray<nsCString>& aDnsSuffixList);
 
  private:
   void EnqueueGenMsg(uint16_t aMsgType, uint8_t aFamily);
@@ -76,6 +77,7 @@ class NetlinkService : public nsIRunnable {
   int GetPollWait();
   bool CalculateIDForFamily(uint8_t aFamily, mozilla::SHA1Sum* aSHA1);
   void CalculateNetworkID();
+  void ComputeDNSSuffixList();
 
   nsCOMPtr<nsIThread> mThread;
 
@@ -108,6 +110,7 @@ class NetlinkService : public nsIRunnable {
   mozilla::TimeStamp mTriggerTime;
 
   nsCString mNetworkId;
+  nsTArray<nsCString> mDNSSuffixList;
 
   class LinkInfo {
    public: