Coverage library on the NS side for the coverage controller

Bug: 289520358

Change-Id: I6c2c0e5db9e8d9a0edec93d2fb123d185c7c4416
diff --git a/trusty/line-coverage/coverage.cpp b/trusty/line-coverage/coverage.cpp
new file mode 100644
index 0000000..57b7025
--- /dev/null
+++ b/trusty/line-coverage/coverage.cpp
@@ -0,0 +1,191 @@
+/*
+ * Copyright (C) 2023 The Android Open Sourete Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "line-coverage"
+
+#include <BufferAllocator/BufferAllocator.h>
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/unique_fd.h>
+#include <assert.h>
+#include <log/log.h>
+#include <stdio.h>
+#include <sys/mman.h>
+#include <sys/uio.h>
+#include <trusty/line-coverage/coverage.h>
+#include <trusty/line-coverage/tipc.h>
+#include <trusty/tipc.h>
+#include <iostream>
+
+#define LINE_COVERAGE_CLIENT_PORT "com.android.trusty.linecoverage.client"
+
+struct control {
+    /* Written by controller, read by instrumented TA */
+    uint64_t        cntrl_flags;
+
+    /* Written by instrumented TA, read by controller */
+    uint64_t        oper_flags;
+    uint64_t        write_buffer_start_count;
+    uint64_t        write_buffer_complete_count;
+};
+
+namespace android {
+namespace trusty {
+namespace line_coverage {
+
+using ::android::base::ErrnoError;
+using ::android::base::Error;
+using ::std::string;
+
+static inline uintptr_t RoundPageUp(uintptr_t val) {
+    return (val + (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
+}
+
+CoverageRecord::CoverageRecord(string tipc_dev, struct uuid* uuid)
+    : tipc_dev_(std::move(tipc_dev)),
+      coverage_srv_fd_(-1),
+      uuid_(*uuid),
+      record_len_(0),
+      shm_(NULL),
+      shm_len_(0) {}
+
+CoverageRecord::~CoverageRecord() {
+    if (shm_) {
+        munmap((void*)shm_, shm_len_);
+    }
+}
+
+volatile void *CoverageRecord::getShm() {
+    if(!IsOpen()) {
+        fprintf(stderr, "Warning! SHM is NULL!\n");
+    }
+    return shm_;
+}
+
+Result<void> CoverageRecord::Rpc(struct line_coverage_client_req* req, \
+                                  int req_fd, \
+                                  struct line_coverage_client_resp* resp) {
+    int rc;
+
+    if (req_fd < 0) {
+        rc = write(coverage_srv_fd_, req, sizeof(*req));
+    } else {
+        iovec iov = {
+                .iov_base = req,
+                .iov_len = sizeof(*req),
+        };
+
+        trusty_shm shm = {
+                .fd = req_fd,
+                .transfer = TRUSTY_SHARE,
+        };
+
+        rc = tipc_send(coverage_srv_fd_, &iov, 1, &shm, 1);
+    }
+
+    if (rc != (int)sizeof(*req)) {
+        return ErrnoError() << "failed to send request to coverage server: ";
+    }
+
+    rc = read(coverage_srv_fd_, resp, sizeof(*resp));
+    if (rc != (int)sizeof(*resp)) {
+        return ErrnoError() << "failed to read reply from coverage server: ";
+    }
+
+    if (resp->hdr.cmd != (req->hdr.cmd | LINE_COVERAGE_CLIENT_CMD_RESP_BIT)) {
+        return ErrnoError() << "unknown response cmd: " << resp->hdr.cmd;
+    }
+
+    return {};
+}
+
+Result<void> CoverageRecord::Open(int fd) {
+    struct line_coverage_client_req req;
+    struct line_coverage_client_resp resp;
+
+    if (shm_) {
+        return {}; /* already initialized */
+    }
+
+    coverage_srv_fd_= fd;
+
+    req.hdr.cmd = LINE_COVERAGE_CLIENT_CMD_OPEN;
+    req.open_args.uuid = uuid_;
+    auto ret = Rpc(&req, -1, &resp);
+    if (!ret.ok()) {
+        return Error() << "failed to open coverage client: " << ret.error();
+    }
+    record_len_ = resp.open_args.record_len;
+    shm_len_ = RoundPageUp(record_len_);
+
+    BufferAllocator allocator;
+
+    fd = allocator.Alloc("system", shm_len_);
+    if (fd < 0) {
+        return ErrnoError() << "failed to create dmabuf of size " << shm_len_
+                            << " err code: " << fd;
+    }
+    unique_fd dma_buf(fd);
+
+    void* shm = mmap(0, shm_len_, PROT_READ | PROT_WRITE, MAP_SHARED, dma_buf, 0);
+    if (shm == MAP_FAILED) {
+        return ErrnoError() << "failed to map memfd: ";
+    }
+
+    req.hdr.cmd = LINE_COVERAGE_CLIENT_CMD_SHARE_RECORD;
+    req.share_record_args.shm_len = shm_len_;
+    ret = Rpc(&req, dma_buf, &resp);
+    if (!ret.ok()) {
+        return Error() << "failed to send shared memory: " << ret.error();
+    }
+
+    shm_ = shm;
+
+    req.hdr.cmd = LINE_COVERAGE_CLIENT_CMD_OPEN;
+    req.open_args.uuid = uuid_;
+    ret = Rpc(&req, -1, &resp);
+    if (!ret.ok()) {
+        return Error() << "failed to open coverage client: " << ret.error();
+    }
+
+    return {};
+}
+
+bool CoverageRecord::IsOpen() {
+    return shm_;
+}
+
+Result<void> CoverageRecord::SaveFile(const std::string& filename) {
+    if(!IsOpen()) {
+        return ErrnoError() << "Warning! SHM is NULL!";
+    }
+    android::base::unique_fd output_fd(TEMP_FAILURE_RETRY(creat(filename.c_str(), 00644)));
+    if (!output_fd.ok()) {
+        return ErrnoError() << "Could not open output file";
+    }
+
+    uintptr_t* begin = (uintptr_t*)((char *)shm_ + sizeof(struct control));
+    bool ret = WriteFully(output_fd, begin, record_len_);
+    if(!ret) {
+        fprintf(stderr, "Coverage write to file failed\n");
+    }
+
+    return {};
+}
+
+}  // namespace line_coverage
+}  // namespace trusty
+}  // namespace android