Support fcntl 'F_GETPIPE_SZ'

stevenengler · stevenengler · commit 975f18bf89bb · 2021-09-24T16:37:13.000-04:00
diff --git a/src/main/host/descriptor/pipe.rs b/src/main/host/descriptor/pipe.rs
@@ -50,6 +50,10 @@ impl PipeFile {
         self.mode
     }
 
+    pub fn max_size(&self) -> usize {
+        self.buffer.borrow().max_len()
+    }
+
     pub fn close(&mut self, event_queue: &mut EventQueue) -> SyscallResult {
         // set the closed flag and remove the active flag
         self.copy_state(
@@ -227,6 +231,10 @@ impl SharedBuf {
         self.queue.len() == 0
     }
 
+    pub fn max_len(&self) -> usize {
+        self.max_len
+    }
+
     pub fn space_available(&self) -> usize {
         self.max_len - self.queue.len()
     }
diff --git a/src/main/host/syscall/fcntl.rs b/src/main/host/syscall/fcntl.rs
@@ -1,6 +1,6 @@
 use crate::cshadow;
 use crate::host::context::{ThreadContext, ThreadContextObjs};
-use crate::host::descriptor::{CompatDescriptor, DescriptorFlags, FileStatus};
+use crate::host::descriptor::{CompatDescriptor, DescriptorFlags, FileStatus, PosixFile};
 use crate::host::syscall;
 use crate::host::syscall_types::SyscallResult;
 use crate::host::syscall_types::{SysCallArgs, SysCallReg};
@@ -93,6 +93,15 @@ fn fcntl(ctx: &mut ThreadContext, args: &SysCallArgs) -> SyscallResult {
                 .register_descriptor_with_min_fd(new_desc, min_fd);
             SysCallReg::from(i32::try_from(new_fd).unwrap())
         }
+        libc::F_GETPIPE_SZ =>
+        {
+            #[allow(irrefutable_let_patterns)]
+            if let PosixFile::Pipe(pipe) = desc.get_file() {
+                SysCallReg::from(i32::try_from(pipe.borrow().max_size()).unwrap())
+            } else {
+                Err(Errno::EINVAL)?
+            }
+        }
         _ => Err(Errno::EINVAL)?,
     })
 }
diff --git a/src/test/pipe/test_pipe.rs b/src/test/pipe/test_pipe.rs
@@ -61,6 +61,11 @@ fn get_tests() -> Vec<test_utils::ShadowTest<(), String>> {
             test_read_from_write_end,
             set![TestEnv::Libc, TestEnv::Shadow],
         ),
+        test_utils::ShadowTest::new(
+            "test_get_size",
+            test_get_size,
+            set![TestEnv::Libc, TestEnv::Shadow],
+        ),
     ];
 
     tests
@@ -296,3 +301,23 @@ fn test_read_from_write_end() -> Result<(), String> {
         Ok(())
     })
 }
+
+fn test_get_size() -> Result<(), String> {
+    let mut fds = [0 as libc::c_int; 2];
+    test_utils::check_system_call!(|| { unsafe { libc::pipe(fds.as_mut_ptr()) } }, &[])?;
+
+    test_utils::result_assert(fds[0] > 0, "fds[0] not set")?;
+    test_utils::result_assert(fds[1] > 0, "fds[1] not set")?;
+
+    let (read_fd, write_fd) = (fds[0], fds[1]);
+
+    test_utils::run_and_close_fds(&[write_fd, read_fd], || {
+        let size = test_utils::check_system_call!(
+            || unsafe { libc::fcntl(read_fd, libc::F_GETPIPE_SZ) },
+            &[]
+        )?;
+        assert!(size > 0);
+
+        Ok(())
+    })
+}

Original file line number	Diff line number	Diff line change
`@@ -50,6 +50,10 @@ impl PipeFile {`
`50`	`50`	`self.mode`
`51`	`51`	`}`
`52`	`52`
	`53`	`+ pub fn max_size(&self) -> usize {`
	`54`	`+ self.buffer.borrow().max_len()`
	`55`	`+ }`
	`56`	`+`
`53`	`57`	`pub fn close(&mut self, event_queue: &mut EventQueue) -> SyscallResult {`
`54`	`58`	`// set the closed flag and remove the active flag`
`55`	`59`	`self.copy_state(`
`@@ -227,6 +231,10 @@ impl SharedBuf {`
`227`	`231`	`self.queue.len() == 0`
`228`	`232`	`}`
`229`	`233`
	`234`	`+ pub fn max_len(&self) -> usize {`
	`235`	`+ self.max_len`
	`236`	`+ }`
	`237`	`+`
`230`	`238`	`pub fn space_available(&self) -> usize {`
`231`	`239`	`self.max_len - self.queue.len()`
`232`	`240`	`}`