From 62bbf3dca964bb98b704d65e0a543cff4bbd0cd2 Mon Sep 17 00:00:00 2001
From: chrisweir <chrisweir@google.com>
Date: Tue, 25 Feb 2020 15:15:40 -0800
Subject: [PATCH] DO NOT MERGE Add support for EFF/RTR to canhalsend

Adding support for extended format frames and remote transmission
request frames to canhalsend.

Bug: 149404884
Test: Manual
Merged-In: I330b9d24c34918b38612ddc1745f019e11bfd474
Change-Id: I330b9d24c34918b38612ddc1745f019e11bfd474
(cherry picked from commit 30bd3dce06e3f20f2bb20473099b8350f1d4cacc)
---
 automotive/can/1.0/tools/canhalsend.cpp | 52 ++++++++++++++++++-------
 1 file changed, 37 insertions(+), 15 deletions(-)

diff --git a/automotive/can/1.0/tools/canhalsend.cpp b/automotive/can/1.0/tools/canhalsend.cpp
index 7e6833a8a6..18e815dd6e 100644
--- a/automotive/can/1.0/tools/canhalsend.cpp
+++ b/automotive/can/1.0/tools/canhalsend.cpp
@@ -15,6 +15,8 @@
  */
 
 #include <android-base/logging.h>
+#include <android-base/parseint.h>
+#include <android-base/strings.h>
 #include <android/hardware/automotive/can/1.0/ICanBus.h>
 #include <android/hidl/manager/1.2/IServiceManager.h>
 
@@ -27,13 +29,13 @@ using ICanBus = V1_0::ICanBus;
 using Result = V1_0::Result;
 
 static void usage() {
-    std::cerr << "cansend - simple command line tool to send raw CAN frames" << std::endl;
+    std::cerr << "canhalsend - simple command line tool to send raw CAN frames" << std::endl;
     std::cerr << std::endl << "usage:" << std::endl << std::endl;
     std::cerr << "canhalsend <bus name> <can id>#<data>" << std::endl;
     std::cerr << "where:" << std::endl;
-    std::cerr << " bus name - name under which ICanBus is be published" << std::endl;
-    std::cerr << " can id - such as 1a5" << std::endl;
-    std::cerr << " data - such as deadbeef or 010203" << std::endl;
+    std::cerr << " bus name - name under which ICanBus is published" << std::endl;
+    std::cerr << " can id - such as 1a5 or 1fab5982" << std::endl;
+    std::cerr << " data - such as deadbeef, 010203, or R for a remote frame" << std::endl;
 }
 
 // TODO(b/135918744): extract to a new library
@@ -53,18 +55,13 @@ static sp<ICanBus> tryOpen(const std::string& busname) {
     return ICanBus::castFrom(ret);
 }
 
-static int cansend(const std::string& busname, V1_0::CanMessageId msgid,
-                   std::vector<uint8_t> payload) {
+static int cansend(const std::string& busname, const V1_0::CanMessage& msg) {
     auto bus = tryOpen(busname);
     if (bus == nullptr) {
         std::cerr << "Bus " << busname << " is not available" << std::endl;
         return -1;
     }
 
-    V1_0::CanMessage msg = {};
-    msg.id = msgid;
-    msg.payload = payload;
-
     const auto result = bus->send(msg);
     if (result != Result::OK) {
         std::cerr << "Send call failed: " << toString(result) << std::endl;
@@ -73,8 +70,7 @@ static int cansend(const std::string& busname, V1_0::CanMessageId msgid,
     return 0;
 }
 
-static std::optional<std::tuple<V1_0::CanMessageId, std::vector<uint8_t>>> parseCanMessage(
-        const std::string& msg) {
+static std::optional<V1_0::CanMessage> parseCanMessage(const std::string& msg) {
     const auto hashpos = msg.find("#");
     if (hashpos == std::string::npos) return std::nullopt;
 
@@ -85,6 +81,32 @@ static std::optional<std::tuple<V1_0::CanMessageId, std::vector<uint8_t>>> parse
     V1_0::CanMessageId msgid = std::stoi(msgidStr, &idx, 16);
     if (msgidStr[idx] != '\0') return std::nullopt;
 
+    V1_0::CanMessage canmsg = {};
+    canmsg.id = msgid;
+    if (msgid > 0x7FF) {
+        canmsg.isExtendedId = true;
+    }
+
+    if (android::base::StartsWith(payloadStr, "R")) {
+        canmsg.remoteTransmissionRequest = true;
+
+        /* The CAN bus HAL doesn't define a data length code (DLC) field, since it is inferrred
+         * from the payload size. RTR messages indicate to the receiver how many bytes they are
+         * expecting to receive back via the DLC sent with the RTR frame. */
+        if (payloadStr.size() <= 1) return canmsg;
+
+        unsigned int dlc = 0;
+
+        /* The maximum DLC for CAN-FD is 64 bytes and CAN 2.0 is 8 bytes. Limit the size of the DLC
+         * to something memory safe and let the HAL determine if the DLC is valid. */
+        if (!android::base::ParseUint(payloadStr.substr(1), &dlc, 10000u)) {
+            std::cerr << "Invalid DLC for RTR frame!" << std::endl;
+            return std::nullopt;
+        }
+        canmsg.payload.resize(dlc);
+        return canmsg;
+    }
+
     std::vector<uint8_t> payload;
     if (payloadStr.size() % 2 != 0) return std::nullopt;
     for (size_t i = 0; i < payloadStr.size(); i += 2) {
@@ -92,8 +114,9 @@ static std::optional<std::tuple<V1_0::CanMessageId, std::vector<uint8_t>>> parse
         payload.emplace_back(std::stoi(byteStr, &idx, 16));
         if (byteStr[idx] != '\0') return std::nullopt;
     }
+    canmsg.payload = payload;
 
-    return {{msgid, payload}};
+    return canmsg;
 }
 
 static int main(int argc, char* argv[]) {
@@ -117,9 +140,8 @@ static int main(int argc, char* argv[]) {
         std::cerr << "Failed to parse CAN message argument" << std::endl;
         return -1;
     }
-    const auto [msgid, payload] = *canmsg;
 
-    return cansend(busname, msgid, payload);
+    return cansend(busname, *canmsg);
 }
 
 }  // namespace android::hardware::automotive::can