Katbin

format ELF64 executable

STDERR = 2
STDOUT = 1
macro socket domain, type, protocol {
	mov rax, 41
	mov rdi, domain
	mov rsi, type
	mov rdx, protocol
	syscall
}
macro bind sockfd, addr, addrlen {
	mov rax, 49
	mov rdi, sockfd
	mov rsi, addr
	mov rdx, addrlen
	syscall
}
macro listen sockfd, bcklog {
	mov rax, 50
	mov rdi, sockfd
	mov rsi, bcklog
	syscall
}
macro accept sockfd, addr, addrlen {
	mov rax, 43
	mov rdi, addr
	mov rsi, addrlen
	syscall
}
macro write fd, buf, count {
	mov rax, 1
	mov rdi, fd
	mov rsi, buf
	mov rdx, count
	syscall
}	
macro exit ecode {
	mov rax, 60
	mov rdi, ecode 
	syscall
}
segment readable executable
	entry main
main:
	write 1, msg, mlen
	socket 2, 1, 0	; socket(domain, type, protocol)
	write 1, scm, scml
	cmp rax, 0
	jl error
	write 1, ssm, ssmlen	; write(fd, buf, count)
	mov qword [sockfd], rax
	mov word [servaddr.sin_family], 2	; AF_INET = 2
	mov dword [servaddr.sin_addr], 0	; INADDR_ANY = 0
	mov word [servaddr.sin_port], 34865	
	;int bind(int sockfd, const struct sockaddr *addr,
                ;socklen_t addrlen);
	bind [sockfd], servaddr.sin_family, sizeof_servaddr
	write STDOUT, bmsg, bmlen
	cmp rax, 0
	jl error
	write STDOUT, sbm, sbmlen
	listen [sockfd], 5 
	write STDOUT, lmsg, lmlen
	;int accept(int sockfd, struct sockaddr *_Nullable restrict addr,
                  ;socklen_t *_Nullable restrict addrlen);
	accept [sockfd], cliaddr.sin_family, cliaddr_len
	cmp rax, 0
	jl error
	write STDOUT, acm, acmlen
	exit 0
error:
	write STDERR, emsg, emlen
	exit 1	; exit(error_code)

segment readable writeable

struc servaddr_in
{
	.sin_family dw 0
	.sin_port dw 0
	.sin_addr dd 0
	.sin_zero dq 0
}
sockfd dq 0
servaddr servaddr_in	
sizeof_servaddr = $-servaddr.sin_family
cliaddr servaddr_in
cliaddr_len dd sizeof_servaddr 
msg db "INFO: Starting the Web Server...", 10
mlen = $-msg
scm db "INFO: Creating a socket...", 10
scml = $-scm
emsg db "ERROR: something went wrong", 10
emlen = $-emsg
ssm db "INFO: socket creation successful!!", 10
ssmlen = $-ssm
bmsg db "INFO: Binding the socket...", 10
bmlen = $-bmsg
sbm db "INFO: Successfully bound up the socket!!", 10
sbmlen = $-sbm
lmsg db "INFO: Listening to the socket...", 10
lmlen = $-lmsg
acm db "INFO: Accepting the connection...", 10
acmlen = $-acm