SERVASM: Your other webserver.
Minimal x86_64 Linux-only file webserver, written in assembly language. It doesn't allocate any memory, using only stack to serve files.
Not intended for production use.
How it works:
Main process setups listing socket on 8080 port with few system calls:
socket(2)
-> bind(2)
-> listen(2)
After main process blocks on on accept(2)
system call until client connects.
Then it fork(2)
main process passing dealing with request in child process and accept(2)
'ing again in main.
On a child process sets alarm(2)
to drop very slow clients, and recv(2)
headers.
We do couple checks on incoming request (only GET requests are supported). open(2)
file and get its size with fstat(2). write(2)
headers and let the kernel send rest with sendfile(2)
. After we close(2)
socket and file.
In a case of error we exit process with passing system call result as exit code.
Running
Compiling server requires nasm
assembler.
make && ./server
Debugging
make && strace -v -s 512 -f ./server
License
Copyright (c) 2015 Vladimir Terekhov
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.