// Usage: // // dlsym $RTLD_DEFAULT "errno" // static int get_symbol_address(WORD_LIST *list) { int opt; void *handle; void *symbol; char *resultname; char retval[256]; resultname = "DLRETVAL"; reset_internal_getopt(); // $ dlcall [-n name] while ((opt = internal_getopt(list, "n:")) != -1) { switch (opt) { case 'n': resultname = list_optarg; break; default: builtin_usage(); return EX_USAGE; } } // Skip past any options. if ((list = loptend) == NULL || list->next == NULL) { builtin_usage(); return EX_USAGE; } if (check_parse_ulong(list->word->word, (void *) &handle) == 0) { builtin_warning("handle %s %p is not well-formed", list->word->word, handle); return EX_USAGE; } if (!(symbol = dlsym(handle, list->next->word->word))) { builtin_warning("failed to resolve symbol %s, %s", list->next->word->word, dlerror()); return EXECUTION_FAILURE; } snprintf(retval, sizeof retval, "pointer:%p", symbol); fprintf(stderr, "%s\n", retval); bind_variable(resultname, retval, 0); return EXECUTION_SUCCESS; }
// Usage: // // dlopen [-N] [-t] [-d] [-g] [-n] [library] [RTLD_NODELETE|RTLD_GLOBAL|...] [...] // static int open_dynamic_library(WORD_LIST *list) { char varname[1024]; char value[1024]; uint32_t flags; void *handle; int opt; reset_internal_getopt(); flags = RTLD_LAZY; handle = NULL; // Options can either be specified as bash-like flags, or as a list. The // bash-like flags look like this: // // $ dlopen -tg libc.so // while ((opt = internal_getopt(list, "lNtdgn")) != -1) { switch (opt) { // RTLD_LAZY and RTLD_NOW are mutually exclusive. case 'l': flags = (flags & ~RTLD_NOW) | RTLD_LAZY; break; case 'N': flags = (flags & ~RTLD_LAZY) | RTLD_NOW; break; case 't': flags |= RTLD_NOLOAD; break; case 'd': flags |= RTLD_DEEPBIND; break; case 'g': flags |= RTLD_GLOBAL; break; case 'n': flags |= RTLD_NODELETE; break; default: builtin_usage(); return EX_USAGE; } } // Skip past any options. if ((list = loptend) == NULL) { builtin_usage(); return 1; } // Check and decode parameters, which can be specified as strings. // // $ dlopen libc.so RTLD_LAZY RTLD_NODELETE // // or, as an integer // // $ dlopen libc.so 0x10101 // if (list->next) { WORD_LIST *flaglist = list->next; // Caller wants more control over flags, so reset and decode the flags // specified. for (flags = 0; flaglist; flaglist = flaglist->next) { flags |= rtld_flags_decode(flaglist->word->word); } } // Now list->word is the library name. if (!(handle = dlopen(list->word->word, flags))) { builtin_error("dlopen(\"%s\", %#x) failed, %s", list->word->word, flags, dlerror()); return 1; } // Print the handle, although this is not usable unless being used interactively. printf("%p\n", handle); snprintf(varname, sizeof varname, "DLHANDLES[\"%s\"]", basename(list->word->word)); snprintf(value, sizeof value, "%p", handle); // Make the handle available programmatically. if (assign_array_element(varname, value, 4) == NULL) { builtin_error("failed to append element to $DLHANDLES array"); return 1; } return 0; }
// Usage: // // dlcall $RTLD_DEFAULT "printf" "hello %s %u %c" $USER 123 int:10 // static int call_foreign_function(WORD_LIST *list) { unsigned nargs; int opt; ffi_cif cif; ffi_type **argtypes; ffi_type *rettype; void **values; void *handle; void *func; char *prefix; char *format; char *resultname; nargs = 0; argtypes = NULL; values = NULL; format = NULL; prefix = NULL; rettype = &ffi_type_void; resultname = "DLRETVAL"; reset_internal_getopt(); // $ dlcall [-a abi] [-r type] [-n name] while ((opt = internal_getopt(list, "a:r:n:")) != -1) { switch (opt) { case 'a': builtin_warning("FIXME: only abi %u is currently supported", FFI_DEFAULT_ABI); return 1; break; case 'r': if (decode_type_prefix(prefix = list_optarg, NULL, &rettype, NULL, &format) != true) { builtin_warning("failed to parse return type"); return 1; } break; case 'n': resultname = list_optarg; break; default: builtin_usage(); return 1; } } // Skip past any options. if ((list = loptend) == NULL || list->next == NULL) { builtin_usage(); return 1; } if (check_parse_ulong(list->word->word, (void *) &handle) == 0) { builtin_warning("handle %s %p is not well-formed", list->word->word, handle); return 1; } if (!(func = dlsym(handle, list->next->word->word))) { builtin_warning("failed to resolve symbol %s, %s", list->next->word->word, dlerror()); return 1; } // Skip to optional parameters list = list->next->next; while (list) { argtypes = realloc(argtypes, (nargs + 1) * sizeof(ffi_type *)); values = realloc(values, (nargs + 1) * sizeof(void *)); if (decode_primitive_type(list->word->word, &values[nargs], &argtypes[nargs]) != true) { builtin_error("failed to decode type from parameter %s", list->word->word); goto error; } nargs++; list = list->next; } if (ffi_prep_cif(&cif, FFI_DEFAULT_ABI, nargs, rettype, argtypes) == FFI_OK) { char *retval; void *rc = alloca(rettype->size); // Do the call. ffi_call(&cif, func, rc, values); // Print the result. if (format) { switch (rettype->size) { case 1: asprintf(&retval, format, *(uint8_t *) rc); break; case 2: asprintf(&retval, format, *(uint16_t *) rc); break; case 4: asprintf(&retval, format, *(uint32_t *) rc, *(float *) rc); break; case 8: asprintf(&retval, format, *(uint64_t *) rc, *(double *) rc); break; case 16: asprintf(&retval, format, *(long double *) rc); break; default: builtin_error("cannot handle size %lu", rettype->size); abort(); } fprintf(stderr, "%s\n", retval); bind_variable(resultname, retval, 0); free(retval); } } for (unsigned i = 0; i < nargs; i++) free(values[i]); free(values); free(argtypes); return 0; error: for (unsigned i = 0; i < nargs; i++) free(values[i]); free(values); free(argtypes); return 1; }
// Usage: // // dlcall "printf" "hello %s %u %c" $USER 123 int:10 // static int call_foreign_function(WORD_LIST *list) { unsigned nargs; unsigned i; int opt; ffi_cif cif; ffi_type **argtypes; ffi_type *rettype; void **values; void *handle; void *func; char *prefix; char *format; char *resultname; nargs = 0; argtypes = NULL; values = NULL; format = NULL; prefix = NULL; rettype = &ffi_type_void; resultname = "DLRETVAL"; handle = RTLD_DEFAULT; reset_internal_getopt(); // $ dlcall [-a abi] [-r type] [-n name] [-h handle] symbol args... while ((opt = internal_getopt(list, "h:a:r:n:")) != -1) { switch (opt) { case 'a': builtin_warning("FIXME: only abi %u is currently supported", FFI_DEFAULT_ABI); return 1; break; case 'r': if (decode_type_prefix(prefix = list_optarg, NULL, &rettype, NULL, &format) != true) { builtin_warning("failed to parse return type"); return 1; } break; case 'n': resultname = list_optarg; break; case 'h': if (check_parse_ulong(list_optarg, (void *) &handle) == 0) { builtin_warning("handle %s %p is not well-formed", list_optarg, handle); return EXECUTION_FAILURE; } break; default: builtin_usage(); return EX_USAGE; } } // Skip past any options. if ((list = loptend) == NULL) { builtin_usage(); return EX_USAGE; } if (!(func = dlsym(handle, list->word->word))) { builtin_warning("failed to resolve symbol %s, %s", list->word->word, dlerror()); return 1; } // Skip to optional parameters list = list->next; while (list) { argtypes = realloc(argtypes, (nargs + 1) * sizeof(ffi_type *)); values = realloc(values, (nargs + 1) * sizeof(void *)); if (decode_primitive_type(list->word->word, &values[nargs], &argtypes[nargs]) != true) { builtin_error("failed to decode type from parameter %s", list->word->word); goto error; } nargs++; list = list->next; } if (ffi_prep_cif(&cif, FFI_DEFAULT_ABI, nargs, rettype, argtypes) == FFI_OK) { char *retval; void *rc = alloca(rettype->size); // Do the call. ffi_call(&cif, func, rc, values); // Decode the result. if (format) { retval = encode_primitive_type(format, rettype, rc); // If this is an interactive shell, print the output. if (interactive_shell) { fprintf(stderr, "%s\n", retval); } // Save the result to the requested location. bind_variable(resultname, retval, 0); // Bash maintains it's own copy of this string, so we can throw it away. free(retval); } } for (i = 0; i < nargs; i++) free(values[i]); free(values); free(argtypes); return 0; error: for (i = 0; i < nargs; i++) free(values[i]); free(values); free(argtypes); return 1; }
// Usage: // // dlsym $RTLD_DEFAULT "errno" // static int get_symbol_address(WORD_LIST *list) { int opt; void *handle; void *symbol; char *resultname; char *format; char *retval; ffi_type *rettype; handle = RTLD_DEFAULT; resultname = "DLRETVAL"; rettype = NULL; reset_internal_getopt(); // $ dlsym [-n name] [-h handle] symbol while ((opt = internal_getopt(list, "d:h:n:")) != -1) { switch (opt) { case 'd': if (decode_type_prefix(list_optarg, NULL, &rettype, NULL, &format) != true) { builtin_warning("failed to parse dereference type"); return 1; } break; case 'n': resultname = list_optarg; break; case 'h': if (check_parse_ulong(list_optarg, (void *) &handle) == 0) { builtin_warning("handle %s %p is not well-formed", list_optarg, handle); return EXECUTION_FAILURE; } break; default: builtin_usage(); return EX_USAGE; } } // Skip past any options. if ((list = loptend) == NULL) { builtin_usage(); return EX_USAGE; } if (!(symbol = dlsym(handle, list->word->word))) { builtin_warning("failed to resolve symbol %s, %s", list->word->word, dlerror()); return EXECUTION_FAILURE; } if (rettype == NULL) { asprintf(&retval, "pointer:%p", symbol); } else { retval = encode_primitive_type(format, rettype, symbol); } if (interactive_shell) { fprintf(stderr, "%s\n", retval); } bind_variable(resultname, retval, 0); free(retval); return EXECUTION_SUCCESS; }
static int generate_native_callback(WORD_LIST *list) { int nargs; void *callback; ffi_cif *cif; ffi_closure *closure; ffi_type **argtypes; ffi_type *rettype; char **proto; char *resultname = "DLRETVAL"; char opt; reset_internal_getopt(); // $ dlcall [-a abi] [-r type] [-n name] while ((opt = internal_getopt(list, "a:r:n:")) != -1) { switch (opt) { case 'n': resultname = list_optarg; break; default: builtin_usage(); return EX_USAGE; } } // Skip past any options. if ((list = loptend) == NULL || !list->next) { builtin_usage(); return EX_USAGE; } closure = ffi_closure_alloc(sizeof(ffi_closure), &callback); cif = malloc(sizeof(ffi_cif)); argtypes = NULL; proto = malloc(sizeof(char *)); proto[0] = strdup(list->word->word); nargs = 0; list = list->next; // Second parameter must be the return type if (decode_type_prefix(list->word->word, NULL, &rettype, NULL, NULL) != true) { builtin_warning("couldnt parse the return type %s", list->word->word); return EXECUTION_FAILURE; } // Skip past return type list = list->next; while (list) { argtypes = realloc(argtypes, (nargs + 1) * sizeof(ffi_type *)); proto = realloc(proto, (nargs + 1 + 1) * sizeof(char *)); if (decode_type_prefix(list->word->word, NULL, &argtypes[nargs], NULL, &proto[nargs+1]) != true) { builtin_error("failed to decode type from parameter %s", list->word->word); goto error; } list = list->next; nargs++; } if (ffi_prep_cif(cif, FFI_DEFAULT_ABI, nargs, rettype, argtypes) == FFI_OK) { // Initialize the closure. if (ffi_prep_closure_loc(closure, cif, execute_bash_trampoline, proto, callback) == FFI_OK) { char retval[1024]; snprintf(retval, sizeof retval, "pointer:%p", callback); fprintf(stderr, "%s\n", retval); bind_variable(resultname, retval, 0); } } //free(argtypes); return 0; error: //free(argtypes); return 1; }