/* SPDX-License-Identifier: BSD-3-Clause or GPL-2.0-only */ #include <ctype.h> #include <stdlib.h> #include <stdio.h> #include <string.h> #include <fcntl.h> #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include <sys/mman.h> #include <errno.h> #include <inttypes.h> #include <limits.h> #include <assert.h> #include <commonlib/bsd/sysincludes.h> #include <commonlib/bsd/helpers.h> #include "fmap.h" #include "kv_pair.h" #include "valstr.h" const struct valstr flag_lut[] = { { FMAP_AREA_STATIC, "static" }, { FMAP_AREA_COMPRESSED, "compressed" }, { FMAP_AREA_RO, "ro" }, { FMAP_AREA_PRESERVE, "preserve" }, }; /* returns size of fmap data structure if successful, <0 to indicate error */ int fmap_size(const struct fmap *fmap) { if (!fmap) return -1; return sizeof(*fmap) + (le16toh(fmap->nareas) * sizeof(struct fmap_area)); } /* Make a best-effort assessment if the given fmap is real */ static int is_valid_fmap(const struct fmap *fmap) { if (memcmp(fmap, FMAP_SIGNATURE, strlen(FMAP_SIGNATURE)) != 0) return 0; /* strings containing the magic tend to fail here */ if (fmap->ver_major != FMAP_VER_MAJOR) return 0; /* a basic consistency check: flash should be larger than fmap */ if (le32toh(fmap->size) < sizeof(*fmap) + le16toh(fmap->nareas) * sizeof(struct fmap_area)) return 0; /* fmap-alikes along binary data tend to fail on having a valid, * null-terminated string in the name field.*/ int i = 0; while (i < FMAP_STRLEN) { if (fmap->name[i] == 0) break; if (!isgraph(fmap->name[i])) return 0; if (i == FMAP_STRLEN - 1) { /* name is specified to be null terminated single-word string * without spaces. We did not break in the 0 test, we know it * is a printable spaceless string but we're seeing FMAP_STRLEN * symbols, which is one too many. */ return 0; } i++; } return 1; } /* brute force linear search */ static long int fmap_lsearch(const uint8_t *image, size_t len) { unsigned long int offset; int fmap_found = 0; for (offset = 0; offset < len - strlen(FMAP_SIGNATURE); offset++) { if (is_valid_fmap((const struct fmap *)&image[offset])) { fmap_found = 1; break; } } if (!fmap_found) return -1; if (offset + fmap_size((const struct fmap *)&image[offset]) > len) return -1; return offset; } /* if image length is a power of 2, use binary search */ static long int fmap_bsearch(const uint8_t *image, size_t len) { unsigned long int offset = -1; int fmap_found = 0, stride; /* * For efficient operation, we start with the largest stride possible * and then decrease the stride on each iteration. Also, check for a * remainder when modding the offset with the previous stride. This * makes it so that each offset is only checked once. */ for (stride = len / 2; stride >= 16; stride /= 2) { if (fmap_found) break; for (offset = 0; offset < len - strlen(FMAP_SIGNATURE); offset += stride) { if ((offset % (stride * 2) == 0) && (offset != 0)) continue; if (is_valid_fmap( (const struct fmap *)&image[offset])) { fmap_found = 1; break; } } } if (!fmap_found) return -1; if (offset + fmap_size((const struct fmap *)&image[offset]) > len) return -1; return offset; } static int popcnt(unsigned int u) { int count; /* K&R method */ for (count = 0; u; count++) u &= (u - 1); return count; } long int fmap_find(const uint8_t *image, unsigned int image_len) { long int ret = -1; if ((image == NULL) || (image_len == 0)) return -1; if (popcnt(image_len) == 1) ret = fmap_bsearch(image, image_len); else ret = fmap_lsearch(image, image_len); return ret; } int fmap_print(const struct fmap *fmap) { int i; struct kv_pair *kv = NULL; const uint8_t *tmp; kv = kv_pair_new(); if (!kv) return -1; tmp = fmap->signature; kv_pair_fmt(kv, "fmap_signature", "0x%02x%02x%02x%02x%02x%02x%02x%02x", tmp[0], tmp[1], tmp[2], tmp[3], tmp[4], tmp[5], tmp[6], tmp[7]); kv_pair_fmt(kv, "fmap_ver_major", "%d", fmap->ver_major); kv_pair_fmt(kv, "fmap_ver_minor","%d", fmap->ver_minor); kv_pair_fmt(kv, "fmap_base", "0x%016llx", (unsigned long long)le64toh(fmap->base)); kv_pair_fmt(kv, "fmap_size", "0x%04x", le32toh(fmap->size)); kv_pair_fmt(kv, "fmap_name", "%s", fmap->name); kv_pair_fmt(kv, "fmap_nareas", "%d", le16toh(fmap->nareas)); kv_pair_print(kv); kv_pair_free(kv); for (i = 0; i < le16toh(fmap->nareas); i++) { struct kv_pair *pair; uint16_t flags; char *str; pair = kv_pair_new(); if (!pair) return -1; kv_pair_fmt(pair, "area_offset", "0x%08x", le32toh(fmap->areas[i].offset)); kv_pair_fmt(pair, "area_size", "0x%08x", le32toh(fmap->areas[i].size)); kv_pair_fmt(pair, "area_name", "%s", fmap->areas[i].name); kv_pair_fmt(pair, "area_flags_raw", "0x%02x", le16toh(fmap->areas[i].flags)); /* Print descriptive strings for flags rather than the field */ flags = le16toh(fmap->areas[i].flags); str = fmap_flags_to_string(flags); if (str == NULL) { kv_pair_free(pair); return -1; } kv_pair_fmt(pair, "area_flags", "%s", str); free(str); kv_pair_print(pair); kv_pair_free(pair); } return 0; } /* convert raw flags field to user-friendly string */ char *fmap_flags_to_string(uint16_t flags) { char *str = NULL; unsigned int i, total_size; str = malloc(1); str[0] = '\0'; total_size = 1; for (i = 0; i < sizeof(flags) * CHAR_BIT; i++) { if (!flags) break; if (flags & (1 << i)) { const char *tmp = val2str(1 << i, flag_lut); total_size += strlen(tmp); str = realloc(str, total_size); strcat(str, tmp); flags &= ~(1 << i); if (flags) { total_size++; str = realloc(str, total_size); strcat(str, ","); } } } return str; } /* allocate and initialize a new fmap structure */ struct fmap *fmap_create(uint64_t base, uint32_t size, uint8_t *name) { struct fmap *fmap; fmap = malloc(sizeof(*fmap)); if (!fmap) return NULL; memset(fmap, 0, sizeof(*fmap)); memcpy(&fmap->signature, FMAP_SIGNATURE, strlen(FMAP_SIGNATURE)); fmap->ver_major = FMAP_VER_MAJOR; fmap->ver_minor = FMAP_VER_MINOR; fmap->base = htole64(base); fmap->size = htole32(size); memccpy(&fmap->name, name, '\0', FMAP_STRLEN); return fmap; } /* free memory used by an fmap structure */ void fmap_destroy(struct fmap *fmap) { free(fmap); } /* append area to existing structure, return new total size if successful */ int fmap_append_area(struct fmap **fmap, uint32_t offset, uint32_t size, const uint8_t *name, uint16_t flags) { struct fmap_area *area; int orig_size, new_size; if ((fmap == NULL || *fmap == NULL) || (name == NULL)) return -1; /* too many areas */ if (le16toh((*fmap)->nareas) >= 0xffff) return -1; orig_size = fmap_size(*fmap); new_size = orig_size + sizeof(*area); *fmap = realloc(*fmap, new_size); if (*fmap == NULL) return -1; area = (struct fmap_area *)((uint8_t *)*fmap + orig_size); memset(area, 0, sizeof(*area)); memccpy(&area->name, name, '\0', FMAP_STRLEN); area->offset = htole32(offset); area->size = htole32(size); area->flags = htole16(flags); (*fmap)->nareas = htole16(le16toh((*fmap)->nareas) + 1); return new_size; } const struct fmap_area *fmap_find_area(const struct fmap *fmap, const char *name) { int i; const struct fmap_area *area = NULL; if (!fmap || !name) return NULL; for (i = 0; i < le16toh(fmap->nareas); i++) { if (!strcmp((const char *)fmap->areas[i].name, name)) { area = &fmap->areas[i]; break; } } return area; } /* * LCOV_EXCL_START * Unit testing stuff done here so we do not need to expose static functions. */ static enum test_status { pass = EXIT_SUCCESS, fail = EXIT_FAILURE } status; static struct fmap *fmap_create_test(void) { struct fmap *fmap; uint64_t base = 0; uint32_t size = 0x100000; char name[] = "test_fmap"; status = fail; fmap = fmap_create(base, size, (uint8_t *)name); if (!fmap) return NULL; if (memcmp(&fmap->signature, FMAP_SIGNATURE, strlen(FMAP_SIGNATURE))) { printf("FAILURE: signature is incorrect\n"); goto fmap_create_test_exit; } if ((fmap->ver_major != FMAP_VER_MAJOR) || (fmap->ver_minor != FMAP_VER_MINOR)) { printf("FAILURE: version is incorrect\n"); goto fmap_create_test_exit; } if (le64toh(fmap->base) != base) { printf("FAILURE: base is incorrect\n"); goto fmap_create_test_exit; } if (le32toh(fmap->size) != 0x100000) { printf("FAILURE: size is incorrect\n"); goto fmap_create_test_exit; } if (strcmp((char *)fmap->name, "test_fmap")) { printf("FAILURE: name is incorrect\n"); goto fmap_create_test_exit; } if (le16toh(fmap->nareas) != 0) { printf("FAILURE: number of areas is incorrect\n"); goto fmap_create_test_exit; } status = pass; fmap_create_test_exit: /* preserve fmap if all went well */ if (status == fail) { fmap_destroy(fmap); fmap = NULL; } return fmap; } static int fmap_print_test(struct fmap *fmap) { return fmap_print(fmap); } static int fmap_size_test(void) { status = fail; if (fmap_size(NULL) >= 0) { printf("FAILURE: failed to abort on NULL pointer input\n"); goto fmap_size_test_exit; } status = pass; fmap_size_test_exit: return status; } /* this test re-allocates the fmap, so it gets a double-pointer */ static int fmap_append_area_test(struct fmap **fmap) { int total_size; uint16_t nareas_orig; /* test_area will be used by fmap_csum_test and find_area_test */ struct fmap_area test_area = { .offset = htole32(0x400), .size = htole32(0x10000), .name = "test_area_1", .flags = htole16(FMAP_AREA_STATIC), }; status = fail; if ((fmap_append_area(NULL, 0, 0, test_area.name, 0) >= 0) || (fmap_append_area(fmap, 0, 0, NULL, 0) >= 0)) { printf("FAILURE: failed to abort on NULL pointer input\n"); goto fmap_append_area_test_exit; } nareas_orig = le16toh((*fmap)->nareas); (*fmap)->nareas = htole16(~(0)); if (fmap_append_area(fmap, 0, 0, (const uint8_t *)"foo", 0) >= 0) { printf("FAILURE: failed to abort with too many areas\n"); goto fmap_append_area_test_exit; } (*fmap)->nareas = htole16(nareas_orig); total_size = sizeof(**fmap) + sizeof(test_area); if (fmap_append_area(fmap, le32toh(test_area.offset), le32toh(test_area.size), test_area.name, le16toh(test_area.flags) ) != total_size) { printf("failed to append area\n"); goto fmap_append_area_test_exit; } if (le16toh((*fmap)->nareas) != 1) { printf("FAILURE: failed to increment number of areas\n"); goto fmap_append_area_test_exit; } status = pass; fmap_append_area_test_exit: return status; } static int fmap_find_area_test(struct fmap *fmap) { status = fail; char area_name[] = "test_area_1"; if (fmap_find_area(NULL, area_name) || fmap_find_area(fmap, NULL)) { printf("FAILURE: failed to abort on NULL pointer input\n"); goto fmap_find_area_test_exit; } if (fmap_find_area(fmap, area_name) == NULL) { printf("FAILURE: failed to find \"%s\"\n", area_name); goto fmap_find_area_test_exit; } status = pass; fmap_find_area_test_exit: return status; } static int fmap_flags_to_string_test(void) { char *str = NULL; char *my_str = NULL; unsigned int i; uint16_t flags; status = fail; /* no area flag */ str = fmap_flags_to_string(0); if (!str || strcmp(str, "")) { printf("FAILURE: failed to return empty string when no flag" "are set"); goto fmap_flags_to_string_test_exit; } free(str); /* single area flags */ for (i = 0; i < ARRAY_SIZE(flag_lut); i++) { if (!flag_lut[i].str) continue; if ((str = fmap_flags_to_string(flag_lut[i].val)) == NULL) { printf("FAILURE: failed to translate flag to string"); goto fmap_flags_to_string_test_exit; } free(str); } /* construct our own flags field and string using all available flags * and compare output with fmap_flags_to_string() */ my_str = calloc(256, 1); flags = 0; for (i = 0; i < ARRAY_SIZE(flag_lut); i++) { if (!flag_lut[i].str) continue; else if (i > 0) strcat(my_str, ","); flags |= flag_lut[i].val; strcat(my_str, flag_lut[i].str); } str = fmap_flags_to_string(flags); if (strcmp(str, my_str)) { printf("FAILURE: bad result from fmap_flags_to_string\n"); goto fmap_flags_to_string_test_exit; } status = pass; fmap_flags_to_string_test_exit: free(str); free(my_str); return status; } static int fmap_find_test(struct fmap *fmap) { uint8_t *buf; size_t total_size, offset; status = fail; /* * Note: In these tests, we'll use fmap_find() and control usage of * lsearch and bsearch by using a power-of-2 total_size. For lsearch, * use total_size - 1. For bsearch, use total_size. */ total_size = 0x100000; buf = calloc(total_size, 1); /* test if image length is zero */ if (fmap_find(buf, 0) >= 0) { printf("FAILURE: failed to abort on zero-length image\n"); goto fmap_find_test_exit; } /* test if no fmap exists */ if (fmap_find(buf, total_size - 1) >= 0) { printf("FAILURE: lsearch returned false positive\n"); goto fmap_find_test_exit; } if (fmap_find(buf, total_size) >= 0) { printf("FAILURE: bsearch returned false positive\n"); goto fmap_find_test_exit; } /* simple test case: fmap at (total_size / 2) + 1 */ offset = (total_size / 2) + 1; memcpy(&buf[offset], fmap, fmap_size(fmap)); if ((unsigned)fmap_find(buf, total_size - 1) != offset) { printf("FAILURE: lsearch failed to find fmap\n"); goto fmap_find_test_exit; } if ((unsigned)fmap_find(buf, total_size) != offset) { printf("FAILURE: bsearch failed to find fmap\n"); goto fmap_find_test_exit; } /* test bsearch if offset is at 0 */ offset = 0; memset(buf, 0, total_size); memcpy(buf, fmap, fmap_size(fmap)); if ((unsigned)fmap_find(buf, total_size) != offset) { printf("FAILURE: bsearch failed to find fmap at offset 0\n"); goto fmap_find_test_exit; } /* test overrun detection */ memset(buf, 0, total_size); memcpy(&buf[total_size - fmap_size(fmap) + 1], fmap, fmap_size(fmap) + 1); if (fmap_find(buf, total_size - 1) >= 0) { printf("FAILURE: lsearch failed to catch overrun\n"); goto fmap_find_test_exit; } if (fmap_find(buf, total_size) >= 0) { printf("FAILURE: bsearch failed to catch overrun\n"); goto fmap_find_test_exit; } status = pass; fmap_find_test_exit: free(buf); return status; } int fmap_test(void) { int rc = EXIT_SUCCESS; struct fmap *my_fmap; /* * This test has two parts: Creation of an fmap with one or more * area(s), and other stuff. Since a valid fmap is required to run * many tests, we abort if fmap creation fails in any way. * * Also, fmap_csum_test() makes some assumptions based on the areas * appended. See fmap_append_area_test() for details. */ if ((my_fmap = fmap_create_test()) == NULL) { rc = EXIT_FAILURE; goto fmap_test_exit; } if (fmap_find_test(my_fmap)) { rc = EXIT_FAILURE; goto fmap_test_exit; } if (fmap_append_area_test(&my_fmap)) { rc = EXIT_FAILURE; goto fmap_test_exit; } rc |= fmap_find_area_test(my_fmap); rc |= fmap_size_test(); rc |= fmap_flags_to_string_test(); rc |= fmap_print_test(my_fmap); fmap_test_exit: fmap_destroy(my_fmap); if (rc) printf("FAILED\n"); return rc; } /* LCOV_EXCL_STOP */