Add support for socket send/receive timeouts.

Only the receive timeout is hooked up yet. You can change the timeout by
calling setsockopt(..., SOL_SOCKET, SO_RCVTIMEO, ...).

Use this mechanism to make /bin/ping report timeouts.

Kernel/IPv4Socket.cpp

@@ -157,10 +157,15 @@ ssize_t IPv4Socket::recvfrom(void* buffer, size_t buffer_length, int flags, cons
     }
     if (packet_buffer.is_null()) {
         current->set_blocked_socket(this);
+        load_receive_deadline();
         block(Process::BlockedReceive);
         Scheduler::yield();
 
         LOCKER(m_lock);
+        if (!m_can_read) {
+            // Unblocked due to timeout.
+            return -EAGAIN;
+        }
         ASSERT(m_can_read);
         ASSERT(!m_receive_queue.is_empty());
         packet_buffer = m_receive_queue.take_first();
@@ -175,10 +180,10 @@ ssize_t IPv4Socket::recvfrom(void* buffer, size_t buffer_length, int flags, cons
 
 void IPv4Socket::did_receive(ByteBuffer&& packet)
 {
-#ifdef IPV4_SOCKET_DEBUG
-    kprintf("IPv4Socket(%p): did_receive %d bytes\n", this, packet.size());
-#endif
     LOCKER(m_lock);
     m_receive_queue.append(move(packet));
     m_can_read = true;
+#ifdef IPV4_SOCKET_DEBUG
+    kprintf("IPv4Socket(%p): did_receive %d bytes, packets in queue: %d\n", this, packet.size(), m_receive_queue.size_slow());
+#endif
 }

Kernel/Process.cpp

@@ -1589,13 +1589,17 @@ int Process::sys$sleep(unsigned seconds)
     return 0;
 }
 
+void kgettimeofday(timeval& tv)
+{
+    tv.tv_sec = RTC::now();
+    tv.tv_usec = (PIT::ticks_since_boot() % 1000) * 1000;
+}
+
 int Process::sys$gettimeofday(timeval* tv)
 {
     if (!validate_write_typed(tv))
         return -EFAULT;
-    auto now = RTC::now();
+    kgettimeofday(*tv);
-    tv->tv_sec = now;
-    tv->tv_usec = (PIT::ticks_since_boot() % 1000) * 1000;
     return 0;
 }
 
@@ -2567,6 +2571,50 @@ ssize_t Process::sys$recvfrom(const Syscall::SC_recvfrom_params* params)
     return socket.recvfrom(buffer, buffer_length, flags, addr, addr_length);
 }
 
+int Process::sys$getsockopt(const Syscall::SC_getsockopt_params* params)
+{
+    if (!validate_read_typed(params))
+        return -EFAULT;
+    int sockfd = params->sockfd;
+    int level = params->level;
+    int option = params->option;
+    auto* value = params->value;
+    auto* value_size = (socklen_t*)params->value_size;
+
+    if (!validate_write_typed(value_size))
+        return -EFAULT;
+    if (!validate_write(value, *value_size))
+        return -EFAULT;
+    auto* descriptor = file_descriptor(sockfd);
+    if (!descriptor)
+        return -EBADF;
+    if (!descriptor->is_socket())
+        return -ENOTSOCK;
+    auto& socket = *descriptor->socket();
+    return socket.getsockopt(level, option, value, value_size);
+}
+
+int Process::sys$setsockopt(const Syscall::SC_setsockopt_params* params)
+{
+    if (!validate_read_typed(params))
+        return -EFAULT;
+    int sockfd = params->sockfd;
+    int level = params->level;
+    int option = params->option;
+    auto* value = params->value;
+    auto value_size = (socklen_t)params->value_size;
+
+    if (!validate_read(value, value_size))
+        return -EFAULT;
+    auto* descriptor = file_descriptor(sockfd);
+    if (!descriptor)
+        return -EBADF;
+    if (!descriptor->is_socket())
+        return -ENOTSOCK;
+    auto& socket = *descriptor->socket();
+    return socket.setsockopt(level, option, value, value_size);
+}
+
 struct SharedBuffer {
     SharedBuffer(pid_t pid1, pid_t pid2, int size)
         : m_pid1(pid1)

Kernel/Process.h

@@ -46,6 +46,8 @@ struct DisplayInfo {
     unsigned pitch;
 };
 
+void kgettimeofday(timeval&);
+
 class Process : public InlineLinkedListNode<Process>, public Weakable<Process> {
     friend class InlineLinkedListNode<Process>;
 public:
@@ -233,6 +235,8 @@ public:
     int sys$connect(int sockfd, const sockaddr*, socklen_t);
     ssize_t sys$sendto(const Syscall::SC_sendto_params*);
     ssize_t sys$recvfrom(const Syscall::SC_recvfrom_params*);
+    int sys$getsockopt(const Syscall::SC_getsockopt_params*);
+    int sys$setsockopt(const Syscall::SC_setsockopt_params*);
     int sys$restore_signal_mask(dword mask);
 
     int sys$create_shared_buffer(pid_t peer_pid, int, void** buffer);

Kernel/Scheduler.cpp

@@ -54,8 +54,11 @@ bool Scheduler::pick_next()
         return context_switch(*s_colonel_process);
     }
 
+    auto now_sec = RTC::now();
+    auto now_usec = (suseconds_t)((PIT::ticks_since_boot() % 1000) * 1000);
+
     // Check and unblock processes whose wait conditions have been met.
-    Process::for_each([] (Process& process) {
+    Process::for_each([&] (Process& process) {
         if (process.state() == Process::BlockedSleep) {
             if (process.wakeup_time() <= system.uptime)
                 process.unblock();
@@ -100,18 +103,19 @@ bool Scheduler::pick_next()
 
         if (process.state() == Process::BlockedReceive) {
             ASSERT(process.m_blocked_socket);
+            auto& socket = *process.m_blocked_socket;
             // FIXME: Block until the amount of data wanted is available.
-            if (process.m_blocked_socket->can_read(SocketRole::None)) {
+            bool timed_out = now_sec > socket.receive_deadline().tv_sec || (now_sec == socket.receive_deadline().tv_sec && now_usec >= socket.receive_deadline().tv_usec);
+            if (timed_out || socket.can_read(SocketRole::None)) {
                 process.unblock();
                 process.m_blocked_socket = nullptr;
+                return true;
             }
             return true;
         }
 
         if (process.state() == Process::BlockedSelect) {
             if (process.m_select_has_timeout) {
-                auto now_sec = RTC::now();
-                auto now_usec = PIT::ticks_since_boot() % 1000;
                 if (now_sec > process.m_select_timeout.tv_sec || (now_sec == process.m_select_timeout.tv_sec && now_usec >= process.m_select_timeout.tv_usec)) {
                     process.unblock();
                     return true;

Kernel/Socket.cpp

@@ -60,3 +60,63 @@ KResult Socket::queue_connection_from(Socket& peer)
     m_pending.append(peer);
     return KSuccess;
 }
+
+KResult Socket::setsockopt(int level, int option, const void* value, socklen_t value_size)
+{
+    ASSERT(level == SOL_SOCKET);
+    switch (option) {
+    case SO_SNDTIMEO:
+        if (value_size != sizeof(timeval))
+            return KResult(-EINVAL);
+        m_send_timeout = *(timeval*)value;
+        return KSuccess;
+    case SO_RCVTIMEO:
+        if (value_size != sizeof(timeval))
+            return KResult(-EINVAL);
+        m_receive_timeout = *(timeval*)value;
+        return KSuccess;
+    default:
+        kprintf("%s(%u): setsockopt() at SOL_SOCKET with unimplemented option %d\n", option);
+        return KResult(-ENOPROTOOPT);
+    }
+}
+
+KResult Socket::getsockopt(int level, int option, void* value, socklen_t* value_size)
+{
+    ASSERT(level == SOL_SOCKET);
+    switch (option) {
+    case SO_SNDTIMEO:
+        if (*value_size < sizeof(timeval))
+            return KResult(-EINVAL);
+        *(timeval*)value = m_send_timeout;
+        *value_size = sizeof(timeval);
+        return KSuccess;
+    case SO_RCVTIMEO:
+        if (*value_size < sizeof(timeval))
+            return KResult(-EINVAL);
+        *(timeval*)value = m_receive_timeout;
+        *value_size = sizeof(timeval);
+        return KSuccess;
+    default:
+        kprintf("%s(%u): getsockopt() at SOL_SOCKET with unimplemented option %d\n", option);
+        return KResult(-ENOPROTOOPT);
+    }
+}
+
+void Socket::load_receive_deadline()
+{
+    kgettimeofday(m_receive_deadline);
+    m_receive_deadline.tv_sec += m_receive_timeout.tv_sec;
+    m_receive_deadline.tv_usec += m_receive_timeout.tv_usec;
+    m_receive_deadline.tv_sec += (m_send_timeout.tv_usec / 1000000) * 1;
+    m_receive_deadline.tv_usec %= 1000000;
+}
+
+void Socket::load_send_deadline()
+{
+    kgettimeofday(m_send_deadline);
+    m_send_deadline.tv_sec += m_send_timeout.tv_sec;
+    m_send_deadline.tv_usec += m_send_timeout.tv_usec;
+    m_send_deadline.tv_sec += (m_send_timeout.tv_usec / 1000000) * 1;
+    m_send_deadline.tv_usec %= 1000000;
+}

Kernel/Socket.h

@@ -38,13 +38,22 @@ public:
     virtual ssize_t sendto(const void*, size_t, int flags, const sockaddr*, socklen_t) = 0;
     virtual ssize_t recvfrom(void*, size_t, int flags, const sockaddr*, socklen_t) = 0;
 
+    KResult setsockopt(int level, int option, const void*, socklen_t);
+    KResult getsockopt(int level, int option, void*, socklen_t*);
+
     pid_t origin_pid() const { return m_origin_pid; }
 
+    timeval receive_deadline() const { return m_receive_deadline; }
+    timeval send_deadline() const { return m_send_deadline; }
+
 protected:
     Socket(int domain, int type, int protocol);
 
     KResult queue_connection_from(Socket&);
 
+    void load_receive_deadline();
+    void load_send_deadline();
+
 private:
     Lock m_lock;
     pid_t m_origin_pid { 0 };
@@ -54,6 +63,12 @@ private:
     int m_backlog { 0 };
     bool m_connected { false };
 
+    timeval m_receive_timeout { 0, 0 };
+    timeval m_send_timeout { 0, 0 };
+
+    timeval m_receive_deadline { 0, 0 };
+    timeval m_send_deadline { 0, 0 };
+
     Vector<RetainPtr<Socket>> m_pending;
     Vector<RetainPtr<Socket>> m_clients;
 };

Kernel/Syscall.cpp

@@ -231,6 +231,10 @@ static dword handle(RegisterDump& regs, dword function, dword arg1, dword arg2,
         return current->sys$sendto((const SC_sendto_params*)arg1);
     case Syscall::SC_recvfrom:
         return current->sys$recvfrom((const SC_recvfrom_params*)arg1);
+    case Syscall::SC_getsockopt:
+        return current->sys$getsockopt((const SC_getsockopt_params*)arg1);
+    case Syscall::SC_setsockopt:
+        return current->sys$setsockopt((const SC_setsockopt_params*)arg1);
     default:
         kprintf("<%u> int0x82: Unknown function %u requested {%x, %x, %x}\n", current->pid(), function, arg1, arg2, arg3);
         break;

Kernel/Syscall.h

@@ -90,6 +90,8 @@
     __ENUMERATE_SYSCALL(seal_shared_buffer) \
     __ENUMERATE_SYSCALL(sendto) \
     __ENUMERATE_SYSCALL(recvfrom) \
+    __ENUMERATE_SYSCALL(getsockopt) \
+    __ENUMERATE_SYSCALL(setsockopt) \
 
 
 namespace Syscall {
@@ -148,6 +150,22 @@ struct SC_recvfrom_params {
     size_t addr_length; // socklen_t
 };
 
+struct SC_getsockopt_params {
+    int sockfd;
+    int level;
+    int option;
+    void* value;
+    void* value_size; // socklen_t*
+};
+
+struct SC_setsockopt_params {
+    int sockfd;
+    int level;
+    int option;
+    const void* value;
+    size_t value_size; // socklen_t
+};
+
 void initialize();
 int sync();
 

Kernel/UnixTypes.h

@@ -325,6 +325,11 @@ struct pollfd {
 #define SOCK_NONBLOCK 04000
 #define SOCK_CLOEXEC 02000000
 
+#define SOL_SOCKET 1
+
+#define SO_RCVTIMEO 1
+#define SO_SNDTIMEO 2
+
 #define IPPROTO_ICMP 1
 #define IPPROTO_TCP 6
 #define IPPROTO_UDP 17

LibC/sys/socket.cpp

@@ -48,4 +48,18 @@ ssize_t recvfrom(int sockfd, void* buffer, size_t buffer_length, int flags, cons
     __RETURN_WITH_ERRNO(rc, rc, -1);
 }
 
+int getsockopt(int sockfd, int level, int option, void* value, socklen_t* value_size)
+{
+    Syscall::SC_getsockopt_params params { sockfd, level, option, value, value_size };
+    int rc = syscall(SC_getsockopt, &params);
+    __RETURN_WITH_ERRNO(rc, rc, -1);
+}
+
+int setsockopt(int sockfd, int level, int option, const void* value, socklen_t value_size)
+{
+    Syscall::SC_setsockopt_params params { sockfd, level, option, value, value_size };
+    int rc = syscall(SC_setsockopt, &params);
+    __RETURN_WITH_ERRNO(rc, rc, -1);
+}
+
 }

LibC/sys/socket.h

@@ -45,6 +45,11 @@ struct sockaddr_in {
     char sin_zero[8];
 };
 
+#define SOL_SOCKET 1
+
+#define SO_RCVTIMEO 1
+#define SO_SNDTIMEO 2
+
 int socket(int domain, int type, int protocol);
 int bind(int sockfd, const sockaddr* addr, socklen_t);
 int listen(int sockfd, int backlog);
@@ -52,6 +57,8 @@ int accept(int sockfd, sockaddr*, socklen_t*);
 int connect(int sockfd, const sockaddr*, socklen_t);
 ssize_t sendto(int sockfd, const void*, size_t, int flags, const struct sockaddr*, socklen_t);
 ssize_t recvfrom(int sockfd, void*, size_t, int flags, const struct sockaddr*, socklen_t);
+int getsockopt(int sockfd, int level, int option, void*, socklen_t*);
+int setsockopt(int sockfd, int level, int option, const void*, socklen_t);
 
 __END_DECLS
 

Userland/ping.cpp

@@ -39,6 +39,13 @@ int main(int argc, char** argv)
         return 1;
     }
 
+    struct timeval timeout { 1, 0 };
+    int rc = setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &timeout, sizeof(timeout));
+    if (rc < 0) {
+        perror("setsockopt");
+        return 1;
+    }
+
     const char* addr_str = "192.168.5.1";
     if (argc > 1)
         addr_str = argv[1];
@@ -50,7 +57,7 @@ int main(int argc, char** argv)
     peer_address.sin_family = AF_INET;
     peer_address.sin_port = 0;
 
-    int rc = inet_pton(AF_INET, addr_str, &peer_address.sin_addr);
+    rc = inet_pton(AF_INET, addr_str, &peer_address.sin_addr);
 
     struct PingPacket {
         struct icmphdr header;
@@ -84,6 +91,10 @@ int main(int argc, char** argv)
         for (;;) {
             rc = recvfrom(fd, &pong_packet, sizeof(PingPacket), 0, (const struct sockaddr*)&peer_address, sizeof(sockaddr_in));
             if (rc < 0) {
+                if (errno == EAGAIN) {
+                    printf("Request (seq=%u) timed out.\n", ntohs(ping_packet.header.un.echo.sequence));
+                    break;
+                }
                 perror("recvfrom");
                 return 1;
             }
@@ -104,12 +115,17 @@ int main(int argc, char** argv)
             int ms = tv_diff.tv_sec * 1000 + tv_diff.tv_usec / 1000;
 
             char addr_buf[64];
-            printf("Pong from %s: id=%u, seq=%u, time=%dms\n",
+            printf("Pong from %s: id=%u, seq=%u%s, time=%dms\n",
                 inet_ntop(AF_INET, &peer_address.sin_addr, addr_buf, sizeof(addr_buf)),
                 ntohs(pong_packet.header.un.echo.id),
                 ntohs(pong_packet.header.un.echo.sequence),
+                pong_packet.header.un.echo.sequence != ping_packet.header.un.echo.sequence ? "(!)" : "",
                 ms
             );
+
+            // If this was a response to an earlier packet, we still need to wait for the current one.
+            if (pong_packet.header.un.echo.sequence != ping_packet.header.un.echo.sequence)
+                continue;
             break;
         }