commit 13fa01fab904679970e4b95357f8eed7327b6d49
author Erik Kline <ek@google.com> Thu Nov 12 17:49:23 2015 +0900
committer Erik Kline <ek@google.com> Fri Nov 13 13:07:31 2015 +0900
tree 700f9f0fc3366ff4646f9f863f92de56cc8acba1
parent e6238a91dc6b775a357e7445b202b88d9e11cfbf

Change dnsmasq input command argument separator

Heretofore netd issued commands to dnsmasq over a stdin channel
using ":" as an argument separator. This make it very complicated
to issue commands that involve IPv6 addresses.

This changes the separator from ":" to "|".

Additionally:

    - Pass DHCP range string literals through to startTethering(),
      still performing string literal to IPv4 address validation.

Bug: 9580643
Change-Id: I210daf311a4c3d84dae3ed054b92c9fa399a791f

server/TetherController.cpp

diff --git a/server/TetherController.cpp b/server/TetherController.cpp
index 88baa31..3b6d0fb 100644
--- a/server/TetherController.cpp
+++ b/server/TetherController.cpp
@@ -41,6 +41,7 @@
 static const char BP_TOOLS_MODE[] = "bp-tools";
 static const char IPV4_FORWARDING_PROC_FILE[] = "/proc/sys/net/ipv4/ip_forward";
 static const char IPV6_FORWARDING_PROC_FILE[] = "/proc/sys/net/ipv6/conf/all/forwarding";
+static const char SEPARATOR[] = "|";
 
 bool writeToFile(const char* filename, const char* value) {
     int fd = open(filename, O_WRONLY);
@@ -121,7 +122,7 @@
 
 #define TETHER_START_CONST_ARG        8
 
-int TetherController::startTethering(int num_addrs, struct in_addr* addrs) {
+int TetherController::startTethering(int num_addrs, char **dhcp_ranges) {
     if (mDaemonPid != 0) {
         ALOGE("Tethering already started");
         errno = EBUSY;
@@ -173,12 +174,9 @@
         args[7] = (char *)"";
 
         int nextArg = TETHER_START_CONST_ARG;
-        for (int addrIndex=0; addrIndex < num_addrs;) {
-            char *start = strdup(inet_ntoa(addrs[addrIndex++]));
-            char *end = strdup(inet_ntoa(addrs[addrIndex++]));
-            asprintf(&(args[nextArg++]),"--dhcp-range=%s,%s,1h", start, end);
-            free(start);
-            free(end);
+        for (int addrIndex = 0; addrIndex < num_addrs; addrIndex += 2) {
+            asprintf(&(args[nextArg++]),"--dhcp-range=%s,%s,1h",
+                     dhcp_ranges[addrIndex], dhcp_ranges[addrIndex+1]);
         }
 
         if (execv(args[0], args)) {
@@ -231,7 +229,7 @@
     fwmark.protectedFromVpn = true;
     fwmark.permission = PERMISSION_SYSTEM;
 
-    snprintf(daemonCmd, sizeof(daemonCmd), "update_dns:0x%x", fwmark.intValue);
+    snprintf(daemonCmd, sizeof(daemonCmd), "update_dns%s0x%x", SEPARATOR, fwmark.intValue);
     int cmdLen = strlen(daemonCmd);
 
     mDnsForwarders->clear();
@@ -252,7 +250,7 @@
             break;
         }
 
-        strcat(daemonCmd, ":");
+        strcat(daemonCmd, SEPARATOR);
         strcat(daemonCmd, servers[i]);
         mDnsForwarders->push_back(a);
     }
@@ -292,7 +290,7 @@
             break;
         }
 
-        strcat(daemonCmd, ":");
+        strcat(daemonCmd, SEPARATOR);
         strcat(daemonCmd, *it);
         haveInterfaces = true;
     }