| ... | ... | @@ -19,6 +19,85 @@ pub const DynLib = switch (builtin.os) { |
| 19 | 19 | else => void, |
| 20 | 20 | }; |
| 21 | 21 | |
| 22 | const LinkMap = extern struct { |
| 23 | l_addr: usize, |
| 24 | l_name: [*]u8, |
| 25 | l_ld: [*c]elf.Dyn, |
| 26 | l_next: [*c]LinkMap, |
| 27 | l_prev: [*c]LinkMap, |
| 28 | |
| 29 | pub const Iterator = struct { |
| 30 | lm_ptr: [*c]LinkMap, |
| 31 | |
| 32 | fn end(self: *const Iterator) bool { |
| 33 | return self.lm_ptr == 0; |
| 34 | } |
| 35 | |
| 36 | fn next(self: *Iterator) ?*LinkMap { |
| 37 | if (self.lm_ptr != 0) { |
| 38 | const ptr = self.lm_ptr; |
| 39 | self.lm_ptr = self.lm_ptr.*.l_next; |
| 40 | return ptr; |
| 41 | } |
| 42 | return null; |
| 43 | } |
| 44 | }; |
| 45 | }; |
| 46 | |
| 47 | const RDebug = extern struct { |
| 48 | r_version: i32, |
| 49 | r_map: [*c]LinkMap, |
| 50 | r_brk: usize, |
| 51 | r_ldbase: usize, |
| 52 | }; |
| 53 | |
| 54 | fn elf_get_va_offset(phdrs: []elf.Phdr) !usize { |
| 55 | for (phdrs) |*phdr| { |
| 56 | if (phdr.p_type == elf.PT_LOAD) { |
| 57 | return @ptrToInt(phdr) - phdr.p_vaddr; |
| 58 | } |
| 59 | } |
| 60 | return error.InvalidExe; |
| 61 | } |
| 62 | |
| 63 | pub fn linkmap_iterator(phdrs: []elf.Phdr) !LinkMap.Iterator { |
| 64 | const va_offset = try elf_get_va_offset(phdrs); |
| 65 | |
| 66 | const dyn_table = init: { |
| 67 | for (phdrs) |*phdr| { |
| 68 | if (phdr.p_type == elf.PT_DYNAMIC) { |
| 69 | const ptr = @intToPtr([*]elf.Dyn, va_offset + phdr.p_vaddr); |
| 70 | break :init ptr[0..phdr.p_memsz / @sizeOf(elf.Dyn)]; |
| 71 | } |
| 72 | } |
| 73 | // No PT_DYNAMIC means this is either a statically-linked program or a |
| 74 | // badly corrupted one |
| 75 | return LinkMap.Iterator{.lm_ptr = 0}; |
| 76 | }; |
| 77 | |
| 78 | const link_map_ptr = init: { |
| 79 | for (dyn_table) |*dyn| { |
| 80 | switch (dyn.d_tag) { |
| 81 | elf.DT_DEBUG => { |
| 82 | const r_debug = @intToPtr(*RDebug, dyn.d_un.d_ptr); |
| 83 | if (r_debug.r_version != 1) return error.InvalidExe; |
| 84 | break :init r_debug.r_map; |
| 85 | }, |
| 86 | elf.DT_PLTGOT => { |
| 87 | const got_table = @intToPtr([*]usize, dyn.d_un.d_ptr); |
| 88 | // The address to the link_map structure is stored in the |
| 89 | // second slot |
| 90 | break :init @intToPtr([*c]LinkMap, got_table[1]); |
| 91 | }, |
| 92 | else => { } |
| 93 | } |
| 94 | } |
| 95 | return error.InvalidExe; |
| 96 | }; |
| 97 | |
| 98 | return LinkMap.Iterator{.lm_ptr = link_map_ptr}; |
| 99 | } |
| 100 | |
| 22 | 101 | pub const LinuxDynLib = struct { |
| 23 | 102 | elf_lib: ElfLib, |
| 24 | 103 | fd: i32, |
LemonBoy <thatlemon@gmail.com> 2019-04-24 20:54:17+02:00