netbpfload: remove support for limiting program types

No need for this, as we simply only support network
program types in the first place.

Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I163e21fd4d4089882cf37fc68bc4299003b514d7

netbpfload/NetBpfLoad.cpp

@@ -72,26 +72,6 @@ constexpr unsigned long long kTetheringApexDomainBitmask =
         domainToBitmask(domain::netd_readonly) |
         domainToBitmask(domain::netd_shared);
 
-// Programs shipped inside the tethering apex should be limited to networking stuff,
-// as KPROBE, PERF_EVENT, TRACEPOINT are dangerous to use from mainline updatable code,
-// since they are less stable abi/api and may conflict with platform uses of bpf.
-constexpr bpf_prog_type kTetheringApexAllowedProgTypes[] = {
-        BPF_PROG_TYPE_CGROUP_SKB,
-        BPF_PROG_TYPE_CGROUP_SOCK,
-        BPF_PROG_TYPE_CGROUP_SOCKOPT,
-        BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-        BPF_PROG_TYPE_CGROUP_SYSCTL,
-        BPF_PROG_TYPE_LWT_IN,
-        BPF_PROG_TYPE_LWT_OUT,
-        BPF_PROG_TYPE_LWT_SEG6LOCAL,
-        BPF_PROG_TYPE_LWT_XMIT,
-        BPF_PROG_TYPE_SCHED_ACT,
-        BPF_PROG_TYPE_SCHED_CLS,
-        BPF_PROG_TYPE_SOCKET_FILTER,
-        BPF_PROG_TYPE_SOCK_OPS,
-        BPF_PROG_TYPE_XDP,
-};
-
 
 const android::bpf::Location locations[] = {
         // S+ Tethering mainline module (network_stack): tether offload
@@ -99,8 +79,6 @@ const android::bpf::Location locations[] = {
                 .dir = "/apex/com.android.tethering/etc/bpf/",
                 .prefix = "tethering/",
                 .allowedDomainBitmask = kTetheringApexDomainBitmask,
-                .allowedProgTypes = kTetheringApexAllowedProgTypes,
-                .allowedProgTypesLength = arraysize(kTetheringApexAllowedProgTypes),
         },
         // T+ Tethering mainline module (shared with netd & system server)
         // netutils_wrapper (for iptables xt_bpf) has access to programs
@@ -108,8 +86,6 @@ const android::bpf::Location locations[] = {
                 .dir = "/apex/com.android.tethering/etc/bpf/netd_shared/",
                 .prefix = "netd_shared/",
                 .allowedDomainBitmask = kTetheringApexDomainBitmask,
-                .allowedProgTypes = kTetheringApexAllowedProgTypes,
-                .allowedProgTypesLength = arraysize(kTetheringApexAllowedProgTypes),
         },
         // T+ Tethering mainline module (shared with netd & system server)
         // netutils_wrapper has no access, netd has read only access
@@ -117,24 +93,18 @@ const android::bpf::Location locations[] = {
                 .dir = "/apex/com.android.tethering/etc/bpf/netd_readonly/",
                 .prefix = "netd_readonly/",
                 .allowedDomainBitmask = kTetheringApexDomainBitmask,
-                .allowedProgTypes = kTetheringApexAllowedProgTypes,
-                .allowedProgTypesLength = arraysize(kTetheringApexAllowedProgTypes),
         },
         // T+ Tethering mainline module (shared with system server)
         {
                 .dir = "/apex/com.android.tethering/etc/bpf/net_shared/",
                 .prefix = "net_shared/",
                 .allowedDomainBitmask = kTetheringApexDomainBitmask,
-                .allowedProgTypes = kTetheringApexAllowedProgTypes,
-                .allowedProgTypesLength = arraysize(kTetheringApexAllowedProgTypes),
         },
         // T+ Tethering mainline module (not shared, just network_stack)
         {
                 .dir = "/apex/com.android.tethering/etc/bpf/net_private/",
                 .prefix = "net_private/",
                 .allowedDomainBitmask = kTetheringApexDomainBitmask,
-                .allowedProgTypes = kTetheringApexAllowedProgTypes,
-                .allowedProgTypesLength = arraysize(kTetheringApexAllowedProgTypes),
         },
 };
 

netbpfload/loader.cpp

@@ -178,6 +178,10 @@ typedef struct {
  *
  * However, be aware that you should not be directly using the SECTION() macro.
  * Instead use the DEFINE_(BPF|XDP)_(PROG|MAP)... & LICENSE/CRITICAL macros.
+ *
+ * Programs shipped inside the tethering apex should be limited to networking stuff,
+ * as KPROBE, PERF_EVENT, TRACEPOINT are dangerous to use from mainline updatable code,
+ * since they are less stable abi/api and may conflict with platform uses of bpf.
  */
 sectionType sectionNameTypes[] = {
         {"bind4/",         BPF_PROG_TYPE_CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_BIND},
@@ -387,19 +391,10 @@ static int readSymTab(ifstream& elfFile, int sort, vector<Elf64_Sym>& data) {
     return 0;
 }
 
-static enum bpf_prog_type getFuseProgType() {
-    int result = BPF_PROG_TYPE_UNSPEC;
-    ifstream("/sys/fs/fuse/bpf_prog_type_fuse") >> result;
-    return static_cast<bpf_prog_type>(result);
-}
-
 static enum bpf_prog_type getSectionType(string& name) {
     for (auto& snt : sectionNameTypes)
         if (StartsWith(name, snt.name)) return snt.type;
 
-    // TODO Remove this code when fuse-bpf is upstream and this BPF_PROG_TYPE_FUSE is fixed
-    if (StartsWith(name, "fuse/")) return getFuseProgType();
-
     return BPF_PROG_TYPE_UNSPEC;
 }
 
@@ -409,6 +404,7 @@ static enum bpf_attach_type getExpectedAttachType(string& name) {
     return BPF_ATTACH_TYPE_UNSPEC;
 }
 
+/*
 static string getSectionName(enum bpf_prog_type type)
 {
     for (auto& snt : sectionNameTypes)
@@ -417,6 +413,7 @@ static string getSectionName(enum bpf_prog_type type)
 
     return "UNKNOWN SECTION NAME " + std::to_string(type);
 }
+*/
 
 static int readProgDefs(ifstream& elfFile, vector<struct bpf_prog_def>& pd,
                         size_t sizeOfBpfProgDef) {
@@ -496,22 +493,8 @@ static int getSectionSymNames(ifstream& elfFile, const string& sectionName, vect
     return 0;
 }
 
-static bool IsAllowed(bpf_prog_type type, const bpf_prog_type* allowed, size_t numAllowed) {
-    if (allowed == nullptr) return true;
-
-    for (size_t i = 0; i < numAllowed; i++) {
-        if (allowed[i] == BPF_PROG_TYPE_UNSPEC) {
-            if (type == getFuseProgType()) return true;
-        } else if (type == allowed[i])
-            return true;
-    }
-
-    return false;
-}
-
 /* Read a section by its index - for ex to get sec hdr strtab blob */
-static int readCodeSections(ifstream& elfFile, vector<codeSection>& cs, size_t sizeOfBpfProgDef,
+static int readCodeSections(ifstream& elfFile, vector<codeSection>& cs, size_t sizeOfBpfProgDef) {
-                            const bpf_prog_type* allowed, size_t numAllowed) {
     vector<Elf64_Shdr> shTable;
     int entries, ret = 0;
 
@@ -538,11 +521,6 @@ static int readCodeSections(ifstream& elfFile, vector<codeSection>& cs, size_t s
 
         if (ptype == BPF_PROG_TYPE_UNSPEC) continue;
 
-        if (!IsAllowed(ptype, allowed, numAllowed)) {
-            ALOGE("Program type %s not permitted here", getSectionName(ptype).c_str());
-            return -1;
-        }
-
         // This must be done before '/' is replaced with '_'.
         cs_temp.expected_attach_type = getExpectedAttachType(name);
 
@@ -1204,8 +1182,7 @@ int loadProg(const char* elfPath, bool* isCritical, const Location& location) {
         return -1;
     }
 
-    ret = readCodeSections(elfFile, cs, sizeOfBpfProgDef, location.allowedProgTypes,
+    ret = readCodeSections(elfFile, cs, sizeOfBpfProgDef);
-                           location.allowedProgTypesLength);
     if (ret) {
         ALOGE("Couldn't read all code sections in %s", elfPath);
         return ret;

netbpfload/loader.h

@@ -76,8 +76,6 @@ struct Location {
     const char* const dir = "";
     const char* const prefix = "";
     unsigned long long allowedDomainBitmask = 0;
-    const bpf_prog_type* allowedProgTypes = nullptr;
-    size_t allowedProgTypesLength = 0;
 };
 
 // BPF loader implementation. Loads an eBPF ELF object