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main.asm
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main.asm
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;asmttpd - Web server for Linux written in amd64 assembly.
;Copyright (C) 2014 Nat <[email protected]>
;
;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/>.
%include "constants.asm"
%include "macros.asm"
%define ASMTTPD_VERSION "0.4.4"
%define THREAD_COUNT 10 ; Number of worker threads
;Follwing amd64 syscall standards for internal function calls: rdi rsi rdx r10 r8 r9
section .data
%include "data.asm"
section .bss
%include "bss.asm"
section .text
%include "string.asm"
%include "http.asm"
%include "syscall.asm"
;%include "mutex.asm"
;%include "debug.asm"
global _start
_start:
mov QWORD [one_constant], 1
mov rdi, start_text
mov rsi, start_text_len
call print_line
mov rdi, [rsp] ;Num of args
cmp rdi,3 ;Exit if no argument, should be directory location
jne exit_with_help
mov rdi, [rsp+16+8]; Port (second) parameter
call string_atoi
xchg al, ah
mov [listen_port], eax
mov rax, [rsp+16] ;Directory (first) parameter
mov [directory_path], rax
; Register signal handlers ( just close all other threads by jumping to SYS_EXIT_GROUP )
mov r10, 8 ; sizeof(sigset_t) displays 128, but strace shows 8 ... so 8 it is! -_-
xor rdx, rdx
mov QWORD [sa_handler], exit
mov rsi, sigaction
mov rdi, SIGINT
mov rax, SYS_RT_SIGACTION
syscall
mov rdi, SIGTERM
mov rax, SYS_RT_SIGACTION
syscall
mov QWORD [sa_handler], SIGIGN
mov rdi, SIGPIPE
mov rax, SYS_RT_SIGACTION
syscall
;Try opening directory
mov rdi, [directory_path]
call sys_open_directory
cmp rax, 0
jl exit_with_no_directory_error
;Create socket
call sys_create_tcp_socket
cmp rax, 0
jl exit_error
mov [listen_socket], rax
;reuseaddr
mov rdi, [listen_socket]
call sys_reuse
;Bind to port
call sys_bind_server
cmp rax, 0
jl exit_bind_error
;Start listening
call sys_listen
;Create threads
mov r10, THREAD_COUNT
thread_pool_setup:
push r10
mov rdi, worker_thread
xor rsi, rsi
call sys_clone
pop r10
dec r10
cmp r10, 0
jne thread_pool_setup
main_thread:
mov rdi, 10
call sys_sleep
jmp main_thread
worker_thread:
mov rbp, rsp
sub rsp, 16
;Offsets: 8 - socket fd, 16 - buffer
mov QWORD [rbp-16], 0 ; Used for pointer to recieve buffer
mov rdi, THREAD_BUFFER_SIZE+2+URL_LENGTH_LIMIT+DIRECTORY_LENGTH_LIMIT ; Allow room to append null, and to create path
call sys_mmap_mem
mov QWORD [rbp-16], rax
worker_thread_start:
call sys_accept
mov [rbp-8], rax ; save fd
mov rdi, rax
call sys_cork ; cork it
worker_thread_continue:
;HTTP Stuff starts here
mov rdi, QWORD [rbp-8] ;fd
mov rsi, [rbp-16] ;buffer
mov rdx, THREAD_BUFFER_SIZE ;size
call sys_recv
cmp rax, 0
jle worker_thread_close
push rax ; save original received length
;stackpush
;push rax
;mov rdi, rsi
;mov rsi, rax
;call print_line ; debug
;pop rax
;stackpop
; add null
mov rdi, [rbp-16]
add rdi, rax
mov BYTE [rdi], 0x00
;Make sure its a valid request
mov rdi, [rbp-16]
mov rsi, crlfx2
call string_ends_with
cmp rax, 1
jne worker_thread_400_response
mov rdi, [rbp-16]
call get_request_type
mov [request_type], rax
cmp BYTE [request_type], REQ_UNK
je worker_thread_400_response
;Find request
mov rax, 0x2F ; '/' character
mov rdi, [rbp-16] ;scan buffer
mov rcx, -1 ;Start count
cld ;Increment rdi
repne scasb
jne worker_thread_400_response
mov rax, -2
sub rax, rcx ;Get the length
mov r8, rax ; start offset for requested file
mov rdi, [rbp-16]
add rdi, r8
mov rax, 0x20 ;'space' character
mov rcx, -1
cld
repne scasb
jne worker_thread_400_response
mov rax, -1
sub rax, rcx
mov r9, rax
add r9, r8 ;end offset
;TODO: Assuming it's a file, need directory handling too
pop r11 ; restore orig recvd length
mov rdi, [rbp-16]
add rdi, r11 ; end of buffer, lets use it!
mov r12, r11 ; keeping count
mov rsi, [directory_path]
xor r15, r15 ; Make sure directory path does not exceed DIRECTORY_LENGTH_LIMIT
worker_thread_append_directory_path:
inc r15
cmp r15, DIRECTORY_LENGTH_LIMIT
je worker_thread_400_response
lodsb
stosb
inc r12
cmp al, 0x00
jne worker_thread_append_directory_path
dec r12 ; get rid of 0x00
;Check if default document needed
cmp r9, [request_offset] ; Offset of document requested
jne no_default_document
mov rsi, default_document
mov rdi, [rbp-16]
add rdi, r12
mov rcx, default_document_len
add r12, rcx
rep movsb
mov r9, r11 ; saving offset into a stack saved register
jmp worker_thread_remove_pre_dir
no_default_document:
; Adds the file to the end of buffer ( where we juts put the document prefix )
mov rsi, [rbp-16]
add rsi, r8 ; points to beginning of path
mov rdi, [rbp-16]
add rdi, r12 ;go to end of buffer
mov rcx, r9
sub rcx, r8
cmp rcx, URL_LENGTH_LIMIT ; Make sure this does not exceed URL_PATH_LENGTH
jg worker_thread_400_response
add r12, rcx
rep movsb
dec r12 ; exclude space character
mov rdi, [rbp-16]
add rdi, r12
mov BYTE [rdi], 0x00 ; add null
mov r9, r11 ; saving offset into a stack saved register
; [rbp-16] + r9 now holds string for file opening
worker_thread_remove_pre_dir:
;-----Simple request logging
;mov rdi, msg_request_log
;mov rsi, msg_request_log_len
;call sys_write
;mov rdi, [rbp-16]
;add rdi, r9
;call get_string_length
;mov rsi, rax
;call print_line
;-----End Simple logging
mov rdi, [rbp-16]
add rdi, r9
mov rsi, filter_prev_dir ; remove any '../'
call string_remove
cmp rax, 0
jne worker_thread_remove_pre_dir
mov rdi, [rbp-16]
add rdi, r9
call detect_content_type
mov r8, rax ;r8: Content Type
worker_thread_response:
;Try to open requested file
mov rdi, [rbp-16]
add rdi, r9
call sys_open
cmp rax, 0
jl worker_thread_404_response ;file not found, so 404
; Done with buffer offsets, put response and data into it starting at beg
mov r10, rax ; r10: file fd
;Determine if request requires a 206 response
mov rdi, r10 ; fd
xor rsi, rsi
mov rdx, LSEEK_END
call sys_lseek
push rax
;Basically if "Range:" is in the header
mov rdi, [rbp-16]
mov rsi, header_range_search
call string_contains
pop rdi
cmp rax, -1
jne worker_thread_206_response
jmp worker_thread_200_response ;else, we're good to go
;---------404 Response Start-------------
worker_thread_404_response:
mov rdi, [rbp-16]
call create_http404_response
;Send response
mov rdi, [rbp-8]
mov rsi, [rbp-16]
mov rdx, rax
call sys_send
;and exit
jmp worker_thread_close
;---------404 Response End--------------
;---------206 Response Start------------
worker_thread_206_response:
; r8: content type , r10: fd, rax: Range: start
push r10
push r8
mov r8, rdi ; r8 now size
;Seek to beg of file
mov rdi, r10 ; fd
mov rsi, 0
mov rdx, LSEEK_SET
call sys_lseek
; find 'bytes='
mov rdi, [rbp-16]
add rdi, rax
mov rsi, find_bytes_range
call string_contains
cmp rax, -1
je worker_thread_400_response
add rdi, rax
add rdi, 6 ; go to number
push rdi ; save beg of first number
mov rax, 0
create_http206_response_lbeg:
inc rdi
inc rax
cmp rax, 200 ; todo tweak this number
jge worker_thread_close_file
cmp BYTE [rdi], 0x2D ; look for '-'
jne create_http206_response_lbeg
mov BYTE [rdi], 0x00 ; replace '-' with null
mov rbx, rdi ; save new beg
inc rbx
pop rdi ; restore beg of first number, convert to int
call string_atoi
mov rdi, rbx ; char after null
mov rbx, rax ; rbx: from byte range
push rdi ; save beginning of 2nd byte range
create_http206_response_rbeg:
inc rdi
cmp BYTE [rdi], 0x0a ; look for end of line
jne create_http206_response_rbeg
dec rdi
mov BYTE [rdi], 0x00; replace end with null
pop rdi ; restore 2nd byte range
call string_atoi
mov rcx,rax ; rcx: to byte range, -1 if there is no end
;byte range: rbx -> rcx(-1 if to end)
cmp rcx, -1
jne worker_thread_206_skip_unknown_end
mov rcx, r8
dec rcx ; zero based
worker_thread_206_skip_unknown_end:
cmp rcx, r8
jge worker_thread_413_response
cmp rbx, rcx
jg worker_thread_416_response
pop r9 ; type
mov r10, r8 ;total
mov rdi, [rbp-16]
mov rsi, rbx ;from
mov r13, rsi ; r13: from offset
mov rdx, rcx ;to
mov r12, rcx ; r12: to byte range
call create_http206_response
mov r9, rax ; r9: header size
sub r12, r13 ; r12: amount to send
inc r12; zero based
;Send it
mov rdi, [rbp-8]
mov rsi, [rbp-16]
mov rdx, r9
call sys_send
pop rdi ; sock fd - stack is empty now
push rdi ; save it so we can close it
mov rsi, r13 ; file offset ( range 'from' )
mov rdx, LSEEK_SET
call sys_lseek
mov rdx, r12 ;file size to send
mov rsi, rdi
mov rdi, [rbp-8]
call sys_sendfile
;stackpush
;push rax
;mov rdi, rsi
;mov rsi, r9
;call print_line ; debug
;pop rax
;stackpop
pop r10; restore fd for close
jmp worker_thread_close_file
;---------206 Response End--------------
;---------200 Response Start------------
worker_thread_200_response:
;rdi - total filesize
push rdi
;Seek to beg of file
mov rdi, r10 ; fd
mov rsi, 0
mov rdx, LSEEK_SET
call sys_lseek
;Create Response
mov rdi, [rbp-16]
mov rsi, r8 ; type, figured out above
pop rdx ; total file size
push rdx ; save for sendfile
call create_http200_response
mov r8, rax ; header size
mov rdi, [rbp-8]
mov rsi, [rbp-16]
mov rdx, rax
call sys_send
cmp rax, 0
jle worker_thread_close_file
cmp BYTE [request_type], REQ_HEAD
je worker_thread_close_file
mov rdi, [rbp-8]
mov rsi, r10
pop rdx
call sys_sendfile
jmp worker_thread_close_file
;---------200 Response End--------------
;---------400 Response Start------------
worker_thread_400_response:
mov rdi, [rbp-16]
mov rsi, 400
call create_httpError_response
mov rdi, [rbp-8]
mov rsi, [rbp-16]
mov rdx, rax
call sys_send
jmp worker_thread_close
;---------400 Response End--------------
;---------413 Response Start------------
worker_thread_413_response:
mov rdi, [rbp-16]
mov rsi, 413
call create_httpError_response
mov rdi, [rbp-8]
mov rsi, [rbp-16]
mov rdx, rax
call sys_send
jmp worker_thread_close
;---------413 Response End--------------
;---------416 Response Start------------
worker_thread_416_response:
mov rdi, [rbp-16]
mov rsi, 416
call create_httpError_response
mov rdi, [rbp-8]
mov rsi, [rbp-16]
mov rdx, rax
call sys_send
jmp worker_thread_close
;---------416 Response End--------------
worker_thread_close_file:
;Uncork
mov rdi, [rbp-8]
call sys_uncork
;Close File
mov rdi, r10
call sys_close
;Close Socket
worker_thread_close:
mov rdi, [rbp-8]
call sys_close
jmp worker_thread_start
exit_with_no_directory_error:
mov rdi, msg_not_a_directory
mov rsi, msg_not_a_directory_len
call print_line
jmp exit
exit_with_help:
mov rdi, msg_help
mov rsi, msg_help_len
call print_line
jmp exit
exit_error:
mov rdi, msg_error
mov rsi, msg_error_len
call print_line
mov rdi, -1
mov rax, SYS_EXIT_GROUP
syscall
jmp exit
exit_bind_error:
mov rdi, msg_bind_error
mov rsi, msg_bind_error_len
call print_line
mov rdi, -1
mov rax, SYS_EXIT_GROUP
syscall
jmp exit
exit_thread:
xor rdi, rdi
mov rax, SYS_EXIT
syscall
jmp exit
exit:
mov rdi, [listen_socket]
call sys_close
xor rdi, rdi
mov rax, SYS_EXIT_GROUP
syscall