diff options
Diffstat (limited to 'sh.s')
| -rw-r--r-- | sh.s | 388 |
1 files changed, 0 insertions, 388 deletions
@@ -1,388 +0,0 @@ -section .text - global _start - -_start: - ; TODO: handle interrupt signal - - push rbp - mov rbp, rsp - sub rsp, 0x110 - mov r15, rsp - sub rsp, 0x110 - mov r9, rsp - sub rsp, 0x110 - mov rbx, rsp - - mov rax, 0x1 - mov rdi, 0x1 - mov rsi, msg - mov rdx, 0x1b - syscall - - jmp parse_path - -rloop: - mov rax, 0x1 - mov rdi, 0x1 - mov rsi, prompt - mov rdx, 0xd - syscall - - mov r8, -0x1 - mov r12, rloopr - jmp bzero - -rloopr: - mov rax, 0x0 - mov rdi, 0x0 - mov rsi, r15 - mov rdx, 0xff - syscall - - ; check for quit - cmp byte [r15], 0x0 - mov r12, quit - je weol - - ; call parse - jmp parse - -exec: - ; fork so we don't hurt ourselves - mov rax, 0x39 - syscall - mov dword [cpid], eax - cmp dword [cpid], 0x0 - jne wait4_it - - ; now that we know what to execute, do so - mov rax, 0x3b - mov rdi, r13 - mov rsi, r14 - mov rdx, 0x0 - syscall - - ; and now kill the child process - jmp quit - -wait4_it: - mov rdi, rax - mov rax, 0x3d - xor rsi, rsi ; null status pointer - xor rdx, rdx - xor rcx, rcx ; null rusage pointer - syscall - - mov dword [cpid], -0x1 - jmp rloop - -; input: none -; output: r9 (path elements), r10 (length) -; clobbered: r8, r12 -; other: r15 (buffer) -parse_path: - mov rax, 0x2 - mov rdi, env - mov rsi, 0x0 - syscall - cmp rax, 0x0 - jl quit - - mov r8, -0x1 - mov r12, parse_path2 - jmp bzero - -parse_path2: - mov rdi, rax - mov rax, 0x0 - mov rsi, r9 - mov rdx, 0xff - syscall - cmp rax, 0x0 - jl quit - mov r8, r9 - dec r8 - -pathfinder: - inc r8 - xor rax, rax - mov byte al, [r8] - cmp al, 0x50 - jne pathfinder - mov byte al, [r8+1] - cmp al, 0x41 - jne pathfinder - mov byte al, [r8+2] - cmp al, 0x54 - jne pathfinder - mov byte al, [r8+3] - cmp al, 0x48 - jne pathfinder - mov byte al, [r8+4] - cmp al, 0x3d - jne pathfinder - mov byte al, [r8+5] - cmp al, 0x22 - jne pathfinder - cmp al, 0x0 - je quit - add r8, 0x6 - mov r10, 0x1 - push 0x0 - push r8 - dec r8 - -pathender: - inc r8 - mov al, [r8] - cmp al, 0x3a - je pathender1 - cmp al, 0x22 - jne pathender - mov byte [r8], 0x0 - mov r9, rsp - jmp rloop - -pathender1: - inc r10 - mov byte [r8], 0x0 - lea rcx, [r8+0x1] - push rcx - jmp pathender - -;input: r8 (iterator), r15 (buffer), r12 (return address) -;output: none -bzero: - inc r8 - mov byte [r8+r15], 0x0 - cmp r8, 0xff - jle bzero - jmp r12 - -;input: r15 (buffer) -;output: r13 (path), r14 (arguments) -;clobbered: r8, rax, rbx, rcx -parse: ; needs special commands: cd exit export echo eval pwd - ;also needs pipes (|, >, <) - push 0x0 - xor r13, r13 - jmp strlen - -; go through and sub/push -parse1: - cmp byte [r8+r15], 0x20 - je subzp - cmp byte [r8+r15], 0x0a - je subz - cmp byte [r8+r15], 0x2f - je sabsf - cmp byte [r8+r15], 0x2e - je sabsf - -parse1r: - dec r8 - cmp r8, 0x0 - jl parse2 - jmp parse1 - -sabsf: - cmp r8, 0x1 - jg parse1r - mov r13, 0x1 - jmp parse1r - -subz: - mov byte [r8+r15], 0x0 - jmp parse1 - -subzp: - mov byte [r8+r15], 0x0 - lea rax, [r8+r15+0x1] - push rax - jmp parse1 - -parse2: - push rbx - mov r14, rsp - cmp r13, 0x0 - jg parse7 - mov r8, -0x1 - -parse3: - inc r8 - cmp r8, r10 - je parse4 - mov r13, r15 - mov rcx, [r9+r8*8] - push r8 - jmp concat - -parse4: ; not found - mov rax, 0x1 - mov rdi, 0x1 - mov rsi, nfe - mov rdx, 0x1a - syscall - jmp rloop - -parse5: ; test rbx - pop r8 - - mov rax, 0x2 - mov rdi, rbx - xor rsi, rsi - xor rdx, rdx - syscall - - cmp rax, 0x0 - jl parse3 - - mov rdi, rax - mov rax, 0x3 - syscall - -parse6: ; found it - mov r13, rbx - jmp exec - -parse7: ; absolute path - mov rax, 0x2 - mov rdi, r15 - xor rsi, rsi - xor rdx, rdx - syscall - - cmp rax, 0x0 - jl parse4 - - mov rdi, rax - mov rax, 0x3 - syscall - - mov r13, r15 - jmp exec - - -;input: r12 (return address), r15 (buffer) -;output: r8 (length) -strlen: - xor r8, r8 - -strlen1: - cmp byte [r8+r15], 0x0 - je parse1 - cmp byte [r8+r15], 0xa - je parse1 - inc r8 - jmp strlen1 - -; input: rcx (a), r13 (b) -; output: rbx (string) -; clobbered: r8, r11 -concat: - mov r8, -0x1 - jmp jlen1 - -jlen1: - inc r8 - cmp byte [r8+rcx], 0x0 - je jlen02 - cmp byte [r8+rcx], 0xa - je jlen02 - jmp jlen1 - -jlen02: - dec r8 - mov r11, -0x1 - -jlen2: - inc r8 - inc r11 - cmp byte [r11+r13], 0x0 - je treg - cmp byte [r11+r13], 0xa - je treg - jmp jlen2 - -treg: - cmp r8, 0xff - jg boe - xchg r15, rbx - mov r8, -0x1 - mov r12, rsinc - jmp bzero - -rsinc: - xchg r15, rbx - mov r8, -0x1 - mov r11, -0x1 - -join1: - inc r8 - cmp byte [r8+rcx], 0x0 - je join02 - cmp byte [r8+rcx], 0xa - je join02 - mov al, [r8+rcx] - mov [r8+rbx], al - jmp join1 - -join02: - mov byte [r8+rbx], 0x2f -join2: - inc r8 - inc r11 - cmp byte [r11+r13], 0x0 - je parse5 - cmp byte [r11+r13], 0xa - je parse5 - mov al, [r11+r13] - mov [r8+rbx], al - jmp join2 - -boe: - mov rax, 0x1 - mov rdi, 0x1 - mov rsi, boem - mov rdx, 0x1f - jmp quit - -; interrupt signal handler -sigint: - cmp dword [cpid], 0x0 - jl sigint_nc - -sigint_c: ; kill the child - mov rax, 0x3e - mov rdi, [cpid] - mov rsi, 0x2 - syscall - -sigint_nc: - mov r12, rloop - jmp weol - -; input: r12 (return address) -; output: none -weol: - mov rax, 0x1 - mov rdi, 0x1 - mov rsi, eol - mov rdx, 0x1 - syscall - jmp r12 - -quit: - mov rax, 0x3c - mov rdi, 0x0 - syscall - -section .data - sigs: dd 0x2 - cpid: dd 0x0 - eol: db 0xa - msg: db "Welcome to deadbeef shell", 0x21, 0x0a - prompt: db "[0xdeadbeef]", 0x20 - nfe: db "Error: program not found", 0x2e, 0x0a - env: db "/etc/environment", 0x0 - boem: db "Error: input overflows buffer", 0x2e, 0x0a |