Kernel: read()/write() should respect timeouts when used on a sockets

Move timeout management to the ReadBlocker and WriteBlocker classes.
Also get rid of the specialized ReceiveBlocker since it no longer does
anything that ReadBlocker can't do.

7 files changed, 48 insertions, 57 deletions

diff --git a/Kernel/Net/IPv4Socket.cpp b/Kernel/Net/IPv4Socket.cpp
index b6f78d7c18..368557bb28 100644
--- a/Kernel/Net/IPv4Socket.cpp
+++ b/Kernel/Net/IPv4Socket.cpp
@@ -264,8 +264,7 @@ ssize_t IPv4Socket::recvfrom(FileDescription& description, void* buffer, size_t
                 return -EAGAIN;
             }
 
-            load_receive_deadline();
-            auto res = current->block<Thread::ReceiveBlocker>(description);
+            auto res = current->block<Thread::ReadBlocker>(description);
 
             LOCKER(lock());
             if (!m_can_read) {
@@ -312,8 +311,7 @@ ssize_t IPv4Socket::recvfrom(FileDescription& description, void* buffer, size_t
             return 0;
         }
 
-        load_receive_deadline();
-        auto res = current->block<Thread::ReceiveBlocker>(description);
+        auto res = current->block<Thread::ReadBlocker>(description);
 
         LOCKER(lock());
         if (!m_can_read) {
diff --git a/Kernel/Net/LocalSocket.cpp b/Kernel/Net/LocalSocket.cpp
index e334f41c8f..09df3ce43f 100644
--- a/Kernel/Net/LocalSocket.cpp
+++ b/Kernel/Net/LocalSocket.cpp
@@ -296,7 +296,7 @@ ssize_t LocalSocket::recvfrom(FileDescription& description, void* buffer, size_t
             return -EAGAIN;
         }
     } else if (!can_read(description)) {
-        auto result = current->block<Thread::ReceiveBlocker>(description);
+        auto result = current->block<Thread::ReadBlocker>(description);
         if (result != Thread::BlockResult::WokeNormally)
             return -EINTR;
     }
diff --git a/Kernel/Net/Socket.cpp b/Kernel/Net/Socket.cpp
index 4e8346ce42..a7e755d9d3 100644
--- a/Kernel/Net/Socket.cpp
+++ b/Kernel/Net/Socket.cpp
@@ -147,24 +147,6 @@ KResult Socket::getsockopt(FileDescription&, int level, int option, void* value,
     }
 }
 
-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;
-}
-
 ssize_t Socket::read(FileDescription& description, u8* buffer, ssize_t size)
 {
     return recvfrom(description, buffer, size, 0, nullptr, 0);
diff --git a/Kernel/Net/Socket.h b/Kernel/Net/Socket.h
index 68f076ccef..aa794dadd2 100644
--- a/Kernel/Net/Socket.h
+++ b/Kernel/Net/Socket.h
@@ -112,9 +112,6 @@ public:
     uid_t acceptor_uid() const { return m_acceptor.uid; }
     gid_t acceptor_gid() const { return m_acceptor.gid; }
 
-    timeval receive_deadline() const { return m_receive_deadline; }
-    timeval send_deadline() const { return m_send_deadline; }
-
     Lock& lock() { return m_lock; }
 
     // ^File
@@ -122,14 +119,18 @@ public:
     virtual ssize_t write(FileDescription&, const u8*, ssize_t) override final;
     virtual String absolute_path(const FileDescription&) const override = 0;
 
+
+    bool has_receive_timeout() const { return m_receive_timeout.tv_sec || m_receive_timeout.tv_usec; }
+    const timeval& receive_timeout() const { return m_receive_timeout; }
+
+    bool has_send_timeout() const { return m_send_timeout.tv_sec || m_send_timeout.tv_usec; }
+    const timeval& send_timeout() const { return m_send_timeout; }
+
 protected:
     Socket(int domain, int type, int protocol);
 
     KResult queue_connection_from(NonnullRefPtr<Socket>);
 
-    void load_receive_deadline();
-    void load_send_deadline();
-
     int backlog() const { return m_backlog; }
     void set_backlog(int backlog) { m_backlog = backlog; }
 
@@ -156,9 +157,6 @@ private:
     timeval m_receive_timeout { 0, 0 };
     timeval m_send_timeout { 0, 0 };
 
-    timeval m_receive_deadline { 0, 0 };
-    timeval m_send_deadline { 0, 0 };
-
     NonnullRefPtrVector<Socket> m_pending;
 };
 
diff --git a/Kernel/Process.cpp b/Kernel/Process.cpp
index a2d2c39bb5..0bcc5bc5fa 100644
--- a/Kernel/Process.cpp
+++ b/Kernel/Process.cpp
@@ -1658,6 +1658,8 @@ ssize_t Process::sys$read(int fd, u8* buffer, ssize_t size)
         if (!description->can_read()) {
             if (current->block<Thread::ReadBlocker>(*description) != Thread::BlockResult::WokeNormally)
                 return -EINTR;
+            if (!description->can_read())
+                return -EAGAIN;
         }
     }
     return description->read(buffer, size);
diff --git a/Kernel/Scheduler.cpp b/Kernel/Scheduler.cpp
index c42126e990..d5a6ff9314 100644
--- a/Kernel/Scheduler.cpp
+++ b/Kernel/Scheduler.cpp
@@ -118,21 +118,6 @@ bool Thread::AcceptBlocker::should_unblock(Thread&, time_t, long)
     return socket.can_accept();
 }
 
-Thread::ReceiveBlocker::ReceiveBlocker(const FileDescription& description)
-    : FileDescriptionBlocker(description)
-{
-}
-
-bool Thread::ReceiveBlocker::should_unblock(Thread&, time_t now_sec, long now_usec)
-{
-    auto& socket = *blocked_description().socket();
-    // FIXME: Block until the amount of data wanted is available.
-    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 || blocked_description().can_read())
-        return true;
-    return false;
-}
-
 Thread::ConnectBlocker::ConnectBlocker(const FileDescription& description)
     : FileDescriptionBlocker(description)
 {
@@ -147,21 +132,50 @@ bool Thread::ConnectBlocker::should_unblock(Thread&, time_t, long)
 Thread::WriteBlocker::WriteBlocker(const FileDescription& description)
     : FileDescriptionBlocker(description)
 {
+    if (description.is_socket()) {
+        auto& socket = *description.socket();
+        if (socket.has_send_timeout()) {
+            timeval deadline = kgettimeofday();
+            deadline.tv_sec += socket.send_timeout().tv_sec;
+            deadline.tv_usec += socket.send_timeout().tv_usec;
+            deadline.tv_sec += (socket.send_timeout().tv_usec / 1000000) * 1;
+            deadline.tv_usec %= 1000000;
+            m_deadline = deadline;
+        }
+    }
 }
 
-bool Thread::WriteBlocker::should_unblock(Thread&, time_t, long)
+bool Thread::WriteBlocker::should_unblock(Thread&, time_t now_sec, long now_usec)
 {
+    if (m_deadline.has_value()) {
+        bool timed_out = now_sec > m_deadline.value().tv_sec || (now_sec == m_deadline.value().tv_sec && now_usec >= m_deadline.value().tv_usec);
+        return timed_out || blocked_description().can_write();
+    }
     return blocked_description().can_write();
 }
 
 Thread::ReadBlocker::ReadBlocker(const FileDescription& description)
     : FileDescriptionBlocker(description)
 {
+    if (description.is_socket()) {
+        auto& socket = *description.socket();
+        if (socket.has_receive_timeout()) {
+            timeval deadline = kgettimeofday();
+            deadline.tv_sec += socket.receive_timeout().tv_sec;
+            deadline.tv_usec += socket.receive_timeout().tv_usec;
+            deadline.tv_sec += (socket.receive_timeout().tv_usec / 1000000) * 1;
+            deadline.tv_usec %= 1000000;
+            m_deadline = deadline;
+        }
+    }
 }
 
-bool Thread::ReadBlocker::should_unblock(Thread&, time_t, long)
+bool Thread::ReadBlocker::should_unblock(Thread&, time_t now_sec, long now_usec)
 {
-    // FIXME: Block until the amount of data wanted is available.
+    if (m_deadline.has_value()) {
+        bool timed_out = now_sec > m_deadline.value().tv_sec || (now_sec == m_deadline.value().tv_sec && now_usec >= m_deadline.value().tv_usec);
+        return timed_out || blocked_description().can_read();
+    }
     return blocked_description().can_read();
 }
 
diff --git a/Kernel/Thread.h b/Kernel/Thread.h
index c73c7a5931..76c6f994bd 100644
--- a/Kernel/Thread.h
+++ b/Kernel/Thread.h
@@ -167,13 +167,6 @@ public:
         virtual const char* state_string() const override { return "Accepting"; }
     };
 
-    class ReceiveBlocker final : public FileDescriptionBlocker {
-    public:
-        explicit ReceiveBlocker(const FileDescription&);
-        virtual bool should_unblock(Thread&, time_t, long) override;
-        virtual const char* state_string() const override { return "Receiving"; }
-    };
-
     class ConnectBlocker final : public FileDescriptionBlocker {
     public:
         explicit ConnectBlocker(const FileDescription&);
@@ -186,6 +179,8 @@ public:
         explicit WriteBlocker(const FileDescription&);
         virtual bool should_unblock(Thread&, time_t, long) override;
         virtual const char* state_string() const override { return "Writing"; }
+    private:
+        Optional<timeval> m_deadline;
     };
 
     class ReadBlocker final : public FileDescriptionBlocker {
@@ -193,6 +188,8 @@ public:
         explicit ReadBlocker(const FileDescription&);
         virtual bool should_unblock(Thread&, time_t, long) override;
         virtual const char* state_string() const override { return "Reading"; }
+    private:
+        Optional<timeval> m_deadline;
     };
 
     class ConditionBlocker final : public Blocker {