netbpfload: remove support for limiting selinux contexts

No need for this, as we simply only support those selinux
contexts (and directories) which are available to networking.

Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I35b134c57411f82514b9f7148411f83d3aee1927
diff --git a/netbpfload/NetBpfLoad.cpp b/netbpfload/NetBpfLoad.cpp
index 454cded..b44a0bc 100644
--- a/netbpfload/NetBpfLoad.cpp
+++ b/netbpfload/NetBpfLoad.cpp
@@ -65,46 +65,34 @@
     abort();  // can only hit this if permissions (likely selinux) are screwed up
 }
 
-constexpr unsigned long long kTetheringApexDomainBitmask =
-        domainToBitmask(domain::tethering) |
-        domainToBitmask(domain::net_private) |
-        domainToBitmask(domain::net_shared) |
-        domainToBitmask(domain::netd_readonly) |
-        domainToBitmask(domain::netd_shared);
-
 
 const android::bpf::Location locations[] = {
         // S+ Tethering mainline module (network_stack): tether offload
         {
                 .dir = "/apex/com.android.tethering/etc/bpf/",
                 .prefix = "tethering/",
-                .allowedDomainBitmask = kTetheringApexDomainBitmask,
         },
         // T+ Tethering mainline module (shared with netd & system server)
         // netutils_wrapper (for iptables xt_bpf) has access to programs
         {
                 .dir = "/apex/com.android.tethering/etc/bpf/netd_shared/",
                 .prefix = "netd_shared/",
-                .allowedDomainBitmask = kTetheringApexDomainBitmask,
         },
         // T+ Tethering mainline module (shared with netd & system server)
         // netutils_wrapper has no access, netd has read only access
         {
                 .dir = "/apex/com.android.tethering/etc/bpf/netd_readonly/",
                 .prefix = "netd_readonly/",
-                .allowedDomainBitmask = kTetheringApexDomainBitmask,
         },
         // T+ Tethering mainline module (shared with system server)
         {
                 .dir = "/apex/com.android.tethering/etc/bpf/net_shared/",
                 .prefix = "net_shared/",
-                .allowedDomainBitmask = kTetheringApexDomainBitmask,
         },
         // T+ Tethering mainline module (not shared, just network_stack)
         {
                 .dir = "/apex/com.android.tethering/etc/bpf/net_private/",
                 .prefix = "net_private/",
-                .allowedDomainBitmask = kTetheringApexDomainBitmask,
         },
 };
 
diff --git a/netbpfload/loader.cpp b/netbpfload/loader.cpp
index 9aeb184..c534b2c 100644
--- a/netbpfload/loader.cpp
+++ b/netbpfload/loader.cpp
@@ -621,8 +621,7 @@
 }
 
 static int createMaps(const char* elfPath, ifstream& elfFile, vector<unique_fd>& mapFds,
-                      const char* prefix, const unsigned long long allowedDomainBitmask,
-                      const size_t sizeOfBpfMapDef) {
+                      const char* prefix, const size_t sizeOfBpfMapDef) {
     int ret;
     vector<char> mdData;
     vector<struct bpf_map_def> md;
@@ -733,11 +732,6 @@
 
         domain selinux_context = getDomainFromSelinuxContext(md[i].selinux_context);
         if (specified(selinux_context)) {
-            if (!inDomainBitmask(selinux_context, allowedDomainBitmask)) {
-                ALOGE("map %s has invalid selinux_context of %d (allowed bitmask 0x%llx)",
-                      mapNames[i].c_str(), selinux_context, allowedDomainBitmask);
-                return -EINVAL;
-            }
             ALOGI("map %s selinux_context [%-32s] -> %d -> '%s' (%s)", mapNames[i].c_str(),
                   md[i].selinux_context, selinux_context, lookupSelinuxContext(selinux_context),
                   lookupPinSubdir(selinux_context));
@@ -746,11 +740,6 @@
         domain pin_subdir = getDomainFromPinSubdir(md[i].pin_subdir);
         if (unrecognized(pin_subdir)) return -ENOTDIR;
         if (specified(pin_subdir)) {
-            if (!inDomainBitmask(pin_subdir, allowedDomainBitmask)) {
-                ALOGE("map %s has invalid pin_subdir of %d (allowed bitmask 0x%llx)",
-                      mapNames[i].c_str(), pin_subdir, allowedDomainBitmask);
-                return -EINVAL;
-            }
             ALOGI("map %s pin_subdir [%-32s] -> %d -> '%s'", mapNames[i].c_str(), md[i].pin_subdir,
                   pin_subdir, lookupPinSubdir(pin_subdir));
         }
@@ -921,7 +910,7 @@
 }
 
 static int loadCodeSections(const char* elfPath, vector<codeSection>& cs, const string& license,
-                            const char* prefix, const unsigned long long allowedDomainBitmask) {
+                            const char* prefix) {
     unsigned kvers = kernelVersion();
 
     if (!kvers) {
@@ -980,22 +969,12 @@
         if (unrecognized(pin_subdir)) return -ENOTDIR;
 
         if (specified(selinux_context)) {
-            if (!inDomainBitmask(selinux_context, allowedDomainBitmask)) {
-                ALOGE("prog %s has invalid selinux_context of %d (allowed bitmask 0x%llx)",
-                      name.c_str(), selinux_context, allowedDomainBitmask);
-                return -EINVAL;
-            }
             ALOGI("prog %s selinux_context [%-32s] -> %d -> '%s' (%s)", name.c_str(),
                   cs[i].prog_def->selinux_context, selinux_context,
                   lookupSelinuxContext(selinux_context), lookupPinSubdir(selinux_context));
         }
 
         if (specified(pin_subdir)) {
-            if (!inDomainBitmask(pin_subdir, allowedDomainBitmask)) {
-                ALOGE("prog %s has invalid pin_subdir of %d (allowed bitmask 0x%llx)", name.c_str(),
-                      pin_subdir, allowedDomainBitmask);
-                return -EINVAL;
-            }
             ALOGI("prog %s pin_subdir [%-32s] -> %d -> '%s'", name.c_str(),
                   cs[i].prog_def->pin_subdir, pin_subdir, lookupPinSubdir(pin_subdir));
         }
@@ -1185,8 +1164,7 @@
     /* Just for future debugging */
     if (0) dumpAllCs(cs);
 
-    ret = createMaps(elfPath, elfFile, mapFds, location.prefix, location.allowedDomainBitmask,
-                     sizeOfBpfMapDef);
+    ret = createMaps(elfPath, elfFile, mapFds, location.prefix, sizeOfBpfMapDef);
     if (ret) {
         ALOGE("Failed to create maps: (ret=%d) in %s", ret, elfPath);
         return ret;
@@ -1197,8 +1175,7 @@
 
     applyMapRelo(elfFile, mapFds, cs);
 
-    ret = loadCodeSections(elfPath, cs, string(license.data()), location.prefix,
-                           location.allowedDomainBitmask);
+    ret = loadCodeSections(elfPath, cs, string(license.data()), location.prefix);
     if (ret) ALOGE("Failed to load programs, loadCodeSections ret=%d", ret);
 
     return ret;
diff --git a/netbpfload/loader.h b/netbpfload/loader.h
index 6402cea..b884637 100644
--- a/netbpfload/loader.h
+++ b/netbpfload/loader.h
@@ -64,18 +64,9 @@
     return d != domain::unspecified;
 }
 
-static constexpr unsigned long long domainToBitmask(domain d) {
-    return specified(d) ? 1uLL << (static_cast<int>(d) - 1) : 0;
-}
-
-static constexpr bool inDomainBitmask(domain d, unsigned long long v) {
-    return domainToBitmask(d) & v;
-}
-
 struct Location {
     const char* const dir = "";
     const char* const prefix = "";
-    unsigned long long allowedDomainBitmask = 0;
 };
 
 // BPF loader implementation. Loads an eBPF ELF object