From c4fb60f216a6b9103b6e74e2d775ec74f6c971be Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jackpot51@gmail.com>
Date: Tue, 11 Apr 2017 21:27:39 -0600
Subject: [PATCH] Implement script file support
---
src/syscall/process.rs | 77 ++++++++++++++++++++++++++++++------------
1 file changed, 55 insertions(+), 22 deletions(-)
diff --git a/src/syscall/process.rs b/src/syscall/process.rs
index abee4bc1..8a8fc1c7 100644
--- a/src/syscall/process.rs
+++ b/src/syscall/process.rs
@@ -488,6 +488,14 @@ fn empty(context: &mut context::Context, reaping: bool) {
}
}
+struct ExecFile(FileHandle);
+
+impl Drop for ExecFile {
+ fn drop(&mut self) {
+ let _ = syscall::close(self.0);
+ }
+}
+
pub fn exec(path: &[u8], arg_ptrs: &[[usize; 2]]) -> Result<usize> {
let entry;
let mut sp = ::USER_STACK_OFFSET + ::USER_STACK_SIZE - 256;
@@ -499,37 +507,62 @@ pub fn exec(path: &[u8], arg_ptrs: &[[usize; 2]]) -> Result<usize> {
args.push(arg.to_vec()); // Must be moved into kernel space before exec unmaps all memory
}
- let (uid, gid, canonical) = {
+ let (uid, gid, mut canonical) = {
let contexts = context::contexts();
let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
let context = context_lock.read();
(context.euid, context.egid, context.canonicalize(path))
};
- let file = syscall::open(&canonical, syscall::flag::O_RDONLY)?;
- let mut stat = Stat::default();
- syscall::file_op_mut_slice(syscall::number::SYS_FSTAT, file, &mut stat)?;
+ let mut stat: Stat;
+ let mut data: Vec<u8>;
+ loop {
+ let file = ExecFile(syscall::open(&canonical, syscall::flag::O_RDONLY)?);
- let mut perm = stat.st_mode & 0o7;
- if stat.st_uid == uid {
- perm |= (stat.st_mode >> 6) & 0o7;
- }
- if stat.st_gid == gid {
- perm |= (stat.st_mode >> 3) & 0o7;
- }
- if uid == 0 {
- perm |= 0o7;
- }
+ stat = Stat::default();
+ syscall::file_op_mut_slice(syscall::number::SYS_FSTAT, file.0, &mut stat)?;
- if perm & 0o1 != 0o1 {
- let _ = syscall::close(file);
- return Err(Error::new(EACCES));
- }
+ let mut perm = stat.st_mode & 0o7;
+ if stat.st_uid == uid {
+ perm |= (stat.st_mode >> 6) & 0o7;
+ }
+ if stat.st_gid == gid {
+ perm |= (stat.st_mode >> 3) & 0o7;
+ }
+ if uid == 0 {
+ perm |= 0o7;
+ }
- //TODO: Only read elf header, not entire file. Then read required segments
- let mut data = vec![0; stat.st_size as usize];
- syscall::file_op_mut_slice(syscall::number::SYS_READ, file, &mut data)?;
- let _ = syscall::close(file);
+ if perm & 0o1 != 0o1 {
+ return Err(Error::new(EACCES));
+ }
+
+ //TODO: Only read elf header, not entire file. Then read required segments
+ data = vec![0; stat.st_size as usize];
+ syscall::file_op_mut_slice(syscall::number::SYS_READ, file.0, &mut data)?;
+ drop(file);
+
+ if data.starts_with(b"#!") {
+ if let Some(line) = data[2..].split(|&b| b == b'\n').next() {
+ if ! args.is_empty() {
+ args.remove(0);
+ }
+ args.insert(0, canonical);
+ args.insert(0, line.to_vec());
+ canonical = {
+ let contexts = context::contexts();
+ let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
+ let context = context_lock.read();
+ context.canonicalize(line)
+ };
+ } else {
+ println!("invalid script {}", unsafe { str::from_utf8_unchecked(path) });
+ return Err(Error::new(ENOEXEC));
+ }
+ } else {
+ break;
+ }
+ }
match elf::Elf::from(&data) {
Ok(elf) => {
--
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