diff options
Diffstat (limited to 'frida_mode/src/ranges.c')
| -rw-r--r-- | frida_mode/src/ranges.c | 611 |
1 files changed, 611 insertions, 0 deletions
diff --git a/frida_mode/src/ranges.c b/frida_mode/src/ranges.c new file mode 100644 index 00000000..ef25b371 --- /dev/null +++ b/frida_mode/src/ranges.c @@ -0,0 +1,611 @@ +#include "frida-gum.h" + +#include "debug.h" + +#include "lib.h" +#include "ranges.h" +#include "stalker.h" +#include "util.h" + +#define MAX_RANGES 20 + +typedef struct { + + gchar * suffix; + GumMemoryRange *range; + gboolean done; + +} convert_name_ctx_t; + +GArray *module_ranges = NULL; +GArray *libs_ranges = NULL; +GArray *include_ranges = NULL; +GArray *exclude_ranges = NULL; +GArray *ranges = NULL; + +static void convert_address_token(gchar *token, GumMemoryRange *range) { + + gchar **tokens; + int token_count; + tokens = g_strsplit(token, "-", 2); + for (token_count = 0; tokens[token_count] != NULL; token_count++) {} + + if (token_count != 2) { + + FATAL("Invalid range (should have two addresses seperated by a '-'): %s\n", + token); + + } + + gchar *from_str = tokens[0]; + gchar *to_str = tokens[1]; + + if (!g_str_has_prefix(from_str, "0x")) { + + FATAL("Invalid range: %s - Start address should have 0x prefix: %s\n", + token, from_str); + + } + + if (!g_str_has_prefix(to_str, "0x")) { + + FATAL("Invalid range: %s - End address should have 0x prefix: %s\n", token, + to_str); + + } + + from_str = &from_str[2]; + to_str = &to_str[2]; + + for (char *c = from_str; *c != '\0'; c++) { + + if (!g_ascii_isxdigit(*c)) { + + FATAL("Invalid range: %s - Start address not formed of hex digits: %s\n", + token, from_str); + + } + + } + + for (char *c = to_str; *c != '\0'; c++) { + + if (!g_ascii_isxdigit(*c)) { + + FATAL("Invalid range: %s - End address not formed of hex digits: %s\n", + token, to_str); + + } + + } + + guint64 from = g_ascii_strtoull(from_str, NULL, 16); + if (from == 0) { + + FATAL("Invalid range: %s - Start failed hex conversion: %s\n", token, + from_str); + + } + + guint64 to = g_ascii_strtoull(to_str, NULL, 16); + if (to == 0) { + + FATAL("Invalid range: %s - End failed hex conversion: %s\n", token, to_str); + + } + + if (from >= to) { + + FATAL("Invalid range: %s - Start (0x%016" G_GINT64_MODIFIER + "x) must be less than end " + "(0x%016" G_GINT64_MODIFIER "x)\n", + token, from, to); + + } + + range->base_address = from; + range->size = to - from; + + g_strfreev(tokens); + +} + +static gboolean convert_name_token_for_module(const GumModuleDetails *details, + gpointer user_data) { + + convert_name_ctx_t *ctx = (convert_name_ctx_t *)user_data; + if (details->path == NULL) { return true; }; + + if (!g_str_has_suffix(details->path, ctx->suffix)) { return true; }; + + OKF("Found module - prefix: %s, 0x%016" G_GINT64_MODIFIER + "x-0x%016" G_GINT64_MODIFIER "x %s", + ctx->suffix, details->range->base_address, + details->range->base_address + details->range->size, details->path); + + *ctx->range = *details->range; + ctx->done = true; + return false; + +} + +static void convert_name_token(gchar *token, GumMemoryRange *range) { + + gchar * suffix = g_strconcat("/", token, NULL); + convert_name_ctx_t ctx = {.suffix = suffix, .range = range, .done = false}; + + gum_process_enumerate_modules(convert_name_token_for_module, &ctx); + if (!ctx.done) { FATAL("Failed to resolve module: %s\n", token); } + g_free(suffix); + +} + +static void convert_token(gchar *token, GumMemoryRange *range) { + + if (g_strrstr(token, "-")) { + + convert_address_token(token, range); + + } else { + + convert_name_token(token, range); + + } + + OKF("Converted token: %s -> 0x%016" G_GINT64_MODIFIER + "x-0x%016" G_GINT64_MODIFIER "x\n", + token, range->base_address, range->base_address + range->size); + +} + +gint range_sort(gconstpointer a, gconstpointer b) { + + return ((GumMemoryRange *)a)->base_address - + ((GumMemoryRange *)b)->base_address; + +} + +static gboolean print_ranges_callback(const GumRangeDetails *details, + gpointer user_data) { + + UNUSED_PARAMETER(user_data); + if (details->file == NULL) { + + OKF("MAP - 0x%016" G_GINT64_MODIFIER "x - 0x%016" G_GINT64_MODIFIER "X", + details->range->base_address, + details->range->base_address + details->range->size); + + } else { + + OKF("MAP - 0x%016" G_GINT64_MODIFIER "x - 0x%016" G_GINT64_MODIFIER + "X %s(0x%016" G_GINT64_MODIFIER "x)", + details->range->base_address, + details->range->base_address + details->range->size, + details->file->path, details->file->offset); + + } + + return true; + +} + +static void print_ranges(char *key, GArray *ranges) { + + OKF("Range: %s Length: %d", key, ranges->len); + for (guint i = 0; i < ranges->len; i++) { + + GumMemoryRange *curr = &g_array_index(ranges, GumMemoryRange, i); + GumAddress curr_limit = curr->base_address + curr->size; + OKF("Range: %s Idx: %3d - 0x%016" G_GINT64_MODIFIER + "x-0x%016" G_GINT64_MODIFIER "x", + key, i, curr->base_address, curr_limit); + + } + +} + +static gboolean collect_module_ranges_callback(const GumRangeDetails *details, + gpointer user_data) { + + GArray * ranges = (GArray *)user_data; + GumMemoryRange range = *details->range; + g_array_append_val(ranges, range); + return TRUE; + +} + +static GArray *collect_module_ranges(void) { + + GArray *result; + result = g_array_new(false, false, sizeof(GumMemoryRange)); + gum_process_enumerate_ranges(GUM_PAGE_NO_ACCESS, + collect_module_ranges_callback, result); + print_ranges("Modules", result); + return result; + +} + +static GArray *collect_ranges(char *env_key) { + + char * env_val; + gchar ** tokens; + int token_count; + GumMemoryRange range; + int i; + GArray * result; + + result = g_array_new(false, false, sizeof(GumMemoryRange)); + + env_val = getenv(env_key); + if (env_val == NULL) return result; + + tokens = g_strsplit(env_val, ",", MAX_RANGES); + + for (token_count = 0; tokens[token_count] != NULL; token_count++) + ; + + for (i = 0; i < token_count; i++) { + + convert_token(tokens[i], &range); + g_array_append_val(result, range); + + } + + g_array_sort(result, range_sort); + + /* Check for overlaps */ + for (i = 1; i < token_count; i++) { + + GumMemoryRange *prev = &g_array_index(result, GumMemoryRange, i - 1); + GumMemoryRange *curr = &g_array_index(result, GumMemoryRange, i); + GumAddress prev_limit = prev->base_address + prev->size; + GumAddress curr_limit = curr->base_address + curr->size; + if (prev_limit > curr->base_address) { + + FATAL("OVerlapping ranges 0x%016" G_GINT64_MODIFIER + "x-0x%016" G_GINT64_MODIFIER "x 0x%016" G_GINT64_MODIFIER + "x-0x%016" G_GINT64_MODIFIER "x", + prev->base_address, prev_limit, curr->base_address, curr_limit); + + } + + } + + print_ranges(env_key, result); + + g_strfreev(tokens); + + return result; + +} + +static GArray *collect_libs_ranges(void) { + + GArray * result; + GumMemoryRange range; + result = g_array_new(false, false, sizeof(GumMemoryRange)); + + if (getenv("AFL_INST_LIBS") == NULL) { + + range.base_address = lib_get_text_base(); + range.size = lib_get_text_limit() - lib_get_text_base(); + + } else { + + range.base_address = 0; + range.size = G_MAXULONG; + + } + + g_array_append_val(result, range); + + print_ranges("AFL_INST_LIBS", result); + + return result; + +} + +static gboolean intersect_range(GumMemoryRange *rr, GumMemoryRange *ra, + GumMemoryRange *rb) { + + GumAddress rab = ra->base_address; + GumAddress ral = rab + ra->size; + + GumAddress rbb = rb->base_address; + GumAddress rbl = rbb + rb->size; + + GumAddress rrb = 0; + GumAddress rrl = 0; + + rr->base_address = 0; + rr->size = 0; + + /* ra is before rb */ + if (ral < rbb) { return false; } + + /* ra is after rb */ + if (rab > rbl) { return true; } + + /* The largest of the two base addresses */ + rrb = rab > rbb ? rab : rbb; + + /* The smallest of the two limits */ + rrl = ral < rbl ? ral : rbl; + + rr->base_address = rrb; + rr->size = rrl - rrb; + return true; + +} + +static GArray *intersect_ranges(GArray *a, GArray *b) { + + GArray * result; + GumMemoryRange *ra; + GumMemoryRange *rb; + GumMemoryRange ri; + + result = g_array_new(false, false, sizeof(GumMemoryRange)); + + for (guint i = 0; i < a->len; i++) { + + ra = &g_array_index(a, GumMemoryRange, i); + for (guint j = 0; j < b->len; j++) { + + rb = &g_array_index(b, GumMemoryRange, j); + + if (!intersect_range(&ri, ra, rb)) { break; } + + if (ri.size == 0) { continue; } + + g_array_append_val(result, ri); + + } + + } + + return result; + +} + +static GArray *subtract_ranges(GArray *a, GArray *b) { + + GArray * result; + GumMemoryRange *ra; + GumAddress ral; + GumMemoryRange *rb; + GumMemoryRange ri; + GumMemoryRange rs; + + result = g_array_new(false, false, sizeof(GumMemoryRange)); + + for (guint i = 0; i < a->len; i++) { + + ra = &g_array_index(a, GumMemoryRange, i); + ral = ra->base_address + ra->size; + for (guint j = 0; j < b->len; j++) { + + rb = &g_array_index(b, GumMemoryRange, j); + + /* + * If rb is after ra, we have no more possible intersections and we can + * simply keep the remaining range + */ + if (!intersect_range(&ri, ra, rb)) { break; } + + /* + * If there is no intersection, then rb must be before ra, so we must + * continue + */ + if (ri.size == 0) { continue; } + + /* + * If the intersection is part way through the range, then we keep the + * start of the range + */ + if (ra->base_address < ri.base_address) { + + rs.base_address = ra->base_address; + rs.size = ri.base_address - ra->base_address; + g_array_append_val(result, rs); + + } + + /* + * If the intersection extends past the limit of the range, then we should + * continue with the next range + */ + if ((ri.base_address + ri.size) > ral) { + + ra->base_address = ral; + ra->size = 0; + break; + + } + + /* + * Otherwise we advance the base of the range to the end of the + * intersection and continue with the remainder of the range + */ + ra->base_address = ri.base_address + ri.size; + ra->size = ral - ra->base_address; + + } + + /* + * When we have processed all the possible intersections, we add what is + * left + */ + if (ra->size != 0) g_array_append_val(result, *ra); + + } + + return result; + +} + +static GArray *merge_ranges(GArray *a) { + + GArray * result; + GumMemoryRange rp; + GumMemoryRange *r; + + result = g_array_new(false, false, sizeof(GumMemoryRange)); + if (a->len == 0) return result; + + rp = g_array_index(a, GumMemoryRange, 0); + + for (guint i = 1; i < a->len; i++) { + + r = &g_array_index(a, GumMemoryRange, i); + + if (rp.base_address + rp.size == r->base_address) { + + rp.size += r->size; + + } else { + + g_array_append_val(result, rp); + rp.base_address = r->base_address; + rp.size = r->size; + continue; + + } + + } + + g_array_append_val(result, rp); + + return result; + +} + +static gboolean exclude_ranges_callback(const GumRangeDetails *details, + gpointer user_data) { + + UNUSED_PARAMETER(user_data); + gchar * name; + gboolean found; + GumStalker *stalker; + if (details->file == NULL) { return TRUE; } + name = g_path_get_basename(details->file->path); + + found = (g_strcmp0(name, "afl-frida-trace.so") == 0); + g_free(name); + if (!found) { return TRUE; } + + stalker = stalker_get(); + gum_stalker_exclude(stalker, details->range); + + return FALSE; + +} + +static void ranges_exclude_self(void) { + + gum_process_enumerate_ranges(GUM_PAGE_EXECUTE, exclude_ranges_callback, NULL); + +} + +void ranges_init(void) { + + GumMemoryRange ri; + GArray * step1; + GArray * step2; + GArray * step3; + GArray * step4; + + if (getenv("AFL_FRIDA_DEBUG_MAPS") != NULL) { + + gum_process_enumerate_ranges(GUM_PAGE_NO_ACCESS, print_ranges_callback, + NULL); + + } + + module_ranges = collect_module_ranges(); + libs_ranges = collect_libs_ranges(); + include_ranges = collect_ranges("AFL_FRIDA_INST_RANGES"); + + /* If include ranges is empty, then assume everything is included */ + if (include_ranges->len == 0) { + + ri.base_address = 0; + ri.size = G_MAXULONG; + g_array_append_val(include_ranges, ri); + + } + + exclude_ranges = collect_ranges("AFL_FRIDA_EXCLUDE_RANGES"); + + /* Intersect with .text section of main executable unless AFL_INST_LIBS */ + step1 = intersect_ranges(module_ranges, libs_ranges); + print_ranges("step1", step1); + + /* Intersect with AFL_FRIDA_INST_RANGES */ + step2 = intersect_ranges(step1, include_ranges); + print_ranges("step2", step2); + + /* Subtract AFL_FRIDA_EXCLUDE_RANGES */ + step3 = subtract_ranges(step2, exclude_ranges); + print_ranges("step3", step3); + + /* + * After step3, we have the total ranges to be instrumented, we now subtract + * that from the original ranges of the modules to configure stalker. + */ + + step4 = subtract_ranges(module_ranges, step3); + print_ranges("step4", step4); + + ranges = merge_ranges(step4); + print_ranges("final", ranges); + + g_array_free(step4, TRUE); + g_array_free(step3, TRUE); + g_array_free(step2, TRUE); + g_array_free(step1, TRUE); + + /* *NEVER* stalk the stalker, only bad things will ever come of this! */ + ranges_exclude_self(); + + ranges_exclude(); + +} + +gboolean range_is_excluded(gpointer address) { + + GumAddress test = GUM_ADDRESS(address); + + if (ranges == NULL) { return false; } + + for (guint i = 0; i < ranges->len; i++) { + + GumMemoryRange *curr = &g_array_index(ranges, GumMemoryRange, i); + GumAddress curr_limit = curr->base_address + curr->size; + + if (test < curr->base_address) { return false; } + + if (test < curr_limit) { return true; } + + } + + return false; + +} + +void ranges_exclude() { + + GumMemoryRange *r; + GumStalker * stalker = stalker_get(); + + OKF("Excluding ranges"); + + for (guint i = 0; i < ranges->len; i++) { + + r = &g_array_index(ranges, GumMemoryRange, i); + gum_stalker_exclude(stalker, r); + + } + +} + |