Add timeout support to packet waiting

kernel/include/net/network.hpp

@@ -104,6 +104,14 @@ int64_t listen(size_t socket_fd, bool listen);
  */
 int64_t wait_for_packet(char* buffer, size_t socket_fd);
 
+/*!
+ * \brief Wait for a packet, for some time
+ * \param socket_fd The file descriptor of the packet
+ * \param ms The maximum time, in milliseconds, to wait for a packet
+ * \return the packet index
+ */
+int64_t wait_for_packet(char* buffer, size_t socket_fd, size_t ms);
+
 } // end of network namespace
 
 #endif

kernel/src/net/network.cpp

@@ -264,3 +264,37 @@ int64_t network::wait_for_packet(char* buffer, size_t socket_fd){
 
     return packet.index;
 }
+
+int64_t network::wait_for_packet(char* buffer, size_t socket_fd, size_t ms){
+    if(!scheduler::has_socket(socket_fd)){
+        return -std::ERROR_SOCKET_INVALID_FD;
+    }
+
+    auto& socket = scheduler::get_socket(socket_fd);
+
+    if(!socket.listen){
+        return -std::ERROR_SOCKET_NOT_LISTEN;
+    }
+
+    logging::logf(logging::log_level::TRACE, "network: %u wait for packet on socket %u\n", scheduler::get_pid(), socket_fd);
+
+    if(socket.listen_packets.empty()){
+        if(!ms){
+            return -std::ERROR_SOCKET_TIMEOUT;
+        }
+
+        if(!socket.listen_queue.sleep(ms)){
+            return -std::ERROR_SOCKET_TIMEOUT;
+        }
+    }
+
+    auto packet = socket.listen_packets.pop();
+    std::copy_n(packet.payload, packet.payload_size, buffer);
+
+    // The memory was allocated as a copy by the decoding process, it is safe to remove it here
+    delete[] packet.payload;
+
+    logging::logf(logging::log_level::TRACE, "network: %u received packet on socket %u\n", scheduler::get_pid(), socket_fd);
+
+    return packet.index;
+}

kernel/src/system_calls.cpp

@@ -390,6 +390,17 @@ void sc_wait_for_packet(interrupt::syscall_regs* regs){
     regs->rbx = reinterpret_cast<size_t>(user_buffer);
 }
 
+void sc_wait_for_packet_ms(interrupt::syscall_regs* regs){
+    auto socket_fd = regs->rbx;
+    auto user_buffer = reinterpret_cast<char*>(regs->rcx);
+    auto ms = regs->rdx;
+
+    auto index = network::wait_for_packet(user_buffer, socket_fd, ms);
+
+    regs->rax = index;
+    regs->rbx = reinterpret_cast<size_t>(user_buffer);
+}
+
 } //End of anonymous namespace
 
 void system_call_entry(interrupt::syscall_regs* regs){
@@ -629,6 +640,10 @@ void system_call_entry(interrupt::syscall_regs* regs){
             sc_wait_for_packet(regs);
             break;
 
+        case 0x3006:
+            sc_wait_for_packet_ms(regs);
+            break;
+
         // Special system calls
 
         case 0x6666:

programs/ping/src/main.cpp

@@ -71,20 +71,24 @@ int main(int argc, char* argv[]) {
             return 1;
         }
 
-        auto p = tlib::wait_for_packet(*socket);
+        auto p = tlib::wait_for_packet(*socket, 2000);
         if (!p) {
-            tlib::printf("ping: wait_for_packet error: %s\n", std::error_message(p.error()));
-            return 1;
-        }
-
-        auto* icmp_header = reinterpret_cast<tlib::icmp::header*>(p->payload + p->index);
-
-        auto command_type = static_cast<tlib::icmp::type>(icmp_header->type);
-
-        if(command_type == tlib::icmp::type::ECHO_REPLY){
-            tlib::printf("Reply received from %s\n", ip.c_str());
+            if(p.error() == std::ERROR_SOCKET_TIMEOUT){
+                tlib::printf("%s unreachable\n", ip.c_str());
+            } else {
+                tlib::printf("ping: wait_for_packet error: %s\n", std::error_message(p.error()));
+                return 1;
+            }
         } else {
-            tlib::printf("Unhandled command type received\n");
+            auto* icmp_header = reinterpret_cast<tlib::icmp::header*>(p->payload + p->index);
+
+            auto command_type = static_cast<tlib::icmp::type>(icmp_header->type);
+
+            if(command_type == tlib::icmp::type::ECHO_REPLY){
+                tlib::printf("Reply received from %s\n", ip.c_str());
+            } else {
+                tlib::printf("Unhandled command type received\n");
+            }
         }
 
         tlib::release_packet(*p);

tlib/include/tlib/net.hpp

@@ -30,6 +30,7 @@ std::expected<packet> prepare_packet(size_t socket_fd, void* desc);
 std::expected<void> finalize_packet(size_t socket_fd, packet p);
 std::expected<void> listen(size_t socket_fd, bool l);
 std::expected<packet> wait_for_packet(size_t socket_fd);
+std::expected<packet> wait_for_packet(size_t socket_fd, size_t ms);
 void release_packet(packet& packet);
 
 } // end of namespace tlib

tlib/src/net.cpp

@@ -103,6 +103,27 @@ std::expected<tlib::packet> tlib::wait_for_packet(size_t socket_fd){
     }
 }
 
+std::expected<tlib::packet> tlib::wait_for_packet(size_t socket_fd, size_t ms){
+    auto buffer = malloc(2048);
+
+    int64_t code;
+    uint64_t payload;
+    asm volatile("mov rax, 0x3006; mov rbx, %[socket]; mov rcx, %[buffer]; mov rdx, %[ms]; int 50; mov %[code], rax; mov %[payload], rbx;"
+        : [payload] "=m" (payload), [code] "=m" (code)
+        : [socket] "g" (socket_fd), [buffer] "g" (reinterpret_cast<size_t>(buffer)), [ms] "g" (ms)
+        : "rax", "rbx", "rcx");
+
+    if(code < 0){
+        free(buffer);
+        return std::make_expected_from_error<packet, size_t>(-code);
+    } else {
+        tlib::packet p;
+        p.index = code;
+        p.payload = reinterpret_cast<char*>(payload);
+        return std::make_expected<packet>(p);
+    }
+}
+
 void tlib::release_packet(packet& packet){
     if(packet.payload){
         free(packet.payload);