syscall.asm

;asmttpd - Web server for Linux written in amd64 assembly.
;Copyright (C) 2014  Nathan Torchia <nemasu@gmail.com>
;
;This file is part of asmttpd.
;
;asmttpd is free software: you can redistribute it and/or modify
;it under the terms of the GNU General Public License as published by
;the Free Software Foundation, either version 2 of the License, or
;(at your option) any later version.
;
;asmttpd is distributed in the hope that it will be useful,
;but WITHOUT ANY WARRANTY; without even the implied warranty of
;MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;GNU General Public License for more details.
;
;You should have received a copy of the GNU General Public License
;along with asmttpd.  If not, see <http://www.gnu.org/licenses/>.

section .text

sys_cork:;rdi - socket
    stackpush
    mov r10, one_constant ;pointer to 1
    mov r8, 8        ;sizeof int
    mov rsi, LEVEL_IPPROTO_TCP
    mov rdx, SOCKOPT_TCP_CORK
    mov rax, SYS_SETSOCKOPT
    syscall
    stackpop
    ret

sys_uncork;rdi - socket
    stackpush
    mov r10, one_constant ;pointer to 1
    mov r8, 8        ;sizeof int
    mov rsi, LEVEL_IPPROTO_TCP
    mov rdx, SOCKOPT_TCP_CORK
    mov rax, SYS_SETSOCKOPT
    syscall
    stackpop
    ret

sys_reuse;rdi - socket
    stackpush
    mov r8, 8        ;sizeof int
    mov r10, one_constant      ;pointer to 1
    mov rsi, LEVEL_SOL_TCP 
    mov rdx, SOCKOPT_TCP_REUSEADDR
    mov rax, SYS_SETSOCKOPT
    syscall
    stackpop
    ret

sys_sendfile: ;rdi - outfd, rsi - infd, rdx - file size
    stackpush
    mov r10, rdx
    xor rdx, rdx
    mov rax, SYS_SENDFILE
    syscall
    stackpop
    ret

sys_lseek:; rdi - fd, rsi - offset, rdx - flag
    stackpush
    mov rax, SYS_LSEEK
    syscall
    stackpop
    ret

sys_open:
    stackpush
    mov rsi, OPEN_RDONLY ;flags     
    mov rax, SYS_OPEN
    syscall
    stackpop
    ret

sys_close:
    stackpush
    mov rax, SYS_CLOSE
    syscall
    stackpop
    ret

sys_send:
    stackpush
    xor r10, r10
    xor r8, r8
    xor r9, r9
    mov rax, SYS_SENDTO
    syscall
    stackpop
    ret

sys_recv:
    stackpush
    xor r10, r10 ; flags
    xor r8, r8
    xor r9, r9
    mov rax, SYS_RECVFROM
    syscall
    stackpop
    ret

sys_accept:
    stackpush
    mov rdi, [listen_socket]
    xor rsi, rsi
    xor rdx, rdx
    mov rax, SYS_ACCEPT
    syscall
    stackpop
    ret

sys_listen:
    stackpush
    mov rdi, [listen_socket]
    mov rsi, 100000000;backlog
    mov rax, SYS_LISTEN
    syscall
    stackpop
    ret

sys_bind_server:
    stackpush
    mov rdi, [listen_socket]
    mov rsi, sockaddr_in
    mov rdx, 16
    mov rax, SYS_BIND
    syscall
    stackpop
    ret

sys_create_tcp_socket:
    stackpush
    mov rdi, AF_INET
    mov rsi, SOCK_STREAM
    mov rdx, PROTO_TCP
    mov rax, SYS_SOCKET
    syscall
    stackpop
    ret

sys_open_directory:;rdi = path, rax = ret ( fd )
    stackpush
    mov rsi, OPEN_DIRECTORY | OPEN_RDONLY ;flags 
    mov rax, SYS_OPEN
    syscall
    stackpop
    ret

sys_write:
    stackpush
    mov rdx, rsi ;length
    mov rsi, rdi ;buffer
    mov rdi, FD_STDOUT
    mov rax, SYS_WRITE
    syscall
    stackpop
    ret

sys_nanosleep:
    stackpush
    mov qword [tv_usec], rdi
    mov qword [tv_sec],0
    xor rsi, rsi
    mov rdi, timeval
    mov rax, SYS_NANOSLEEP
    syscall
    stackpop
    ret

sys_sleep:
    stackpush
    mov qword [tv_sec], rdi
    mov qword [tv_usec],0
    xor rsi, rsi
    mov rdi, timeval
    mov rax, SYS_NANOSLEEP
    syscall
    stackpop
    ret

sys_mmap_mem:
    stackpush
    mov rsi, rdi                                                    ;Size
    xor rdi, rdi                                                    ;Preferred address (don't care)
    mov rdx, MMAP_PROT_READ | MMAP_PROT_WRITE                       ;Protection Flags
    mov r10, MMAP_MAP_PRIVATE | MMAP_MAP_ANON                       ;Flags
    xor r8, r8
    dec r8                                                          ;-1 fd because of MMAP_MAP_ANON
    xor r9, r9                                                      ;Offset
    mov rax, SYS_MMAP
    syscall
    stackpop
    ret

sys_mmap_stack:
    stackpush
    mov rsi, rdi                                                    ;Size
    xor rdi, rdi                                                    ;Preferred address (don't care)
    mov rdx, MMAP_PROT_READ | MMAP_PROT_WRITE                       ;Protection Flags
    mov r10, MMAP_MAP_PRIVATE | MMAP_MAP_ANON | MMAP_MAP_GROWSDOWN  ;Flags
    xor r8, r8
    dec r8                                                          ;-1 fd because of MMAP_MAP_ANON
    xor r9, r9                                                      ;Offset
    mov rax, SYS_MMAP
    syscall
    stackpop
    ret

sys_clone: 
    mov r14, rdi      ;Address of the thread_func
    mov r15, rsi      ;Thread Param
    mov rdi, THREAD_STACK_SIZE
    call sys_mmap_stack
    lea rsi, [rax + THREAD_STACK_SIZE]       ;Set newly allocated memory
    mov rdi, CLONE_FILES | CLONE_VM | CLONE_FS | CLONE_THREAD | CLONE_SIGHAND | SIGCHILD ;Flags
    xor r10, r10 ;parent_tid
    xor r8,  r8 ;child_tid
    xor r9,  r9 ;regs
    mov rax, SYS_CLONE
    syscall
    cmp rax, 0 ;If ret is not 0, then it's the ID of the new thread
    jnz parent
    push r14     ;Else,  set new return address
    mov rdi, r15 ;and set param
    ret          ;Return to thread_proc
parent:
    ret