OpenWrt – Rev 4
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/*
* oseama
*
* Copyright (C) 2016 Rafał Miłecki <zajec5@gmail.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*/
#include <byteswap.h>
#include <endian.h>
#include <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "md5.h"
#if !defined(__BYTE_ORDER)
#error "Unknown byte order"
#endif
#if __BYTE_ORDER == __BIG_ENDIAN
#define cpu_to_be32(x) (x)
#define be32_to_cpu(x) (x)
#define cpu_to_be16(x) (x)
#define be16_to_cpu(x) (x)
#elif __BYTE_ORDER == __LITTLE_ENDIAN
#define cpu_to_be32(x) bswap_32(x)
#define be32_to_cpu(x) bswap_32(x)
#define cpu_to_be16(x) bswap_16(x)
#define be16_to_cpu(x) bswap_16(x)
#else
#error "Unsupported endianness"
#endif
#define SEAMA_MAGIC 0x5ea3a417
struct seama_seal_header {
uint32_t magic;
uint16_t reserved;
uint16_t metasize;
uint32_t imagesize;
} __attribute__ ((packed));
struct seama_entity_header {
uint32_t magic;
uint16_t reserved;
uint16_t metasize;
uint32_t imagesize;
uint8_t md5[16];
} __attribute__ ((packed));
char *seama_path;
int entity_idx = -1;
char *out_path;
static inline size_t oseama_min(size_t x, size_t y) {
return x < y ? x : y;
}
/**************************************************
* Info
**************************************************/
static void oseama_info_parse_options(int argc, char **argv) {
int c;
while ((c = getopt(argc, argv, "e:")) != -1) {
switch (c) {
case 'e':
entity_idx = atoi(optarg);
break;
}
}
}
static int oseama_info_entities(FILE *seama) {
struct seama_entity_header hdr;
size_t bytes, metasize, imagesize;
uint8_t buf[1024];
char *end, *tmp;
int i = 0;
int err = 0;
while ((bytes = fread(&hdr, 1, sizeof(hdr), seama)) == sizeof(hdr)) {
if (be32_to_cpu(hdr.magic) != SEAMA_MAGIC) {
fprintf(stderr, "Invalid Seama magic: 0x%08x\n", be32_to_cpu(hdr.magic));
err = -EINVAL;
goto err_out;
}
metasize = be16_to_cpu(hdr.metasize);
imagesize = be32_to_cpu(hdr.imagesize);
if (entity_idx >= 0 && i != entity_idx) {
fseek(seama, metasize + imagesize, SEEK_CUR);
i++;
continue;
}
if (metasize >= sizeof(buf)) {
fprintf(stderr, "Too small buffer (%zu B) to read all meta info (%zd B)\n", sizeof(buf), metasize);
err = -EINVAL;
goto err_out;
}
if (entity_idx < 0)
printf("\n");
printf("Entity offset:\t%ld\n", ftell(seama) - sizeof(hdr));
printf("Entity size:\t%zd\n", sizeof(hdr) + metasize + imagesize);
printf("Meta size:\t%zd\n", metasize);
printf("Image size:\t%zd\n", imagesize);
bytes = fread(buf, 1, metasize, seama);
if (bytes != metasize) {
fprintf(stderr, "Couldn't read %zd B of meta\n", metasize);
err = -EIO;
goto err_out;
}
end = (char *)&buf[metasize - 1];
*end = '\0';
for (tmp = (char *)buf; tmp < end && strlen(tmp); tmp += strlen(tmp) + 1) {
printf("Meta entry:\t%s\n", tmp);
}
fseek(seama, imagesize, SEEK_CUR);
i++;
}
err_out:
return err;
}
static int oseama_info(int argc, char **argv) {
FILE *seama;
struct seama_seal_header hdr;
size_t bytes;
uint16_t metasize;
uint32_t imagesize;
uint8_t buf[1024];
int err = 0;
if (argc < 3) {
fprintf(stderr, "No Seama file passed\n");
err = -EINVAL;
goto out;
}
seama_path = argv[2];
optind = 3;
oseama_info_parse_options(argc, argv);
seama = fopen(seama_path, "r");
if (!seama) {
fprintf(stderr, "Couldn't open %s\n", seama_path);
err = -EACCES;
goto out;
}
bytes = fread(&hdr, 1, sizeof(hdr), seama);
if (bytes != sizeof(hdr)) {
fprintf(stderr, "Couldn't read %s header\n", seama_path);
err = -EIO;
goto err_close;
}
metasize = be16_to_cpu(hdr.metasize);
imagesize = be32_to_cpu(hdr.imagesize);
if (be32_to_cpu(hdr.magic) != SEAMA_MAGIC) {
fprintf(stderr, "Invalid Seama magic: 0x%08x\n", be32_to_cpu(hdr.magic));
err = -EINVAL;
goto err_close;
}
if (metasize >= sizeof(buf)) {
fprintf(stderr, "Too small buffer (%zu B) to read all meta info (%d B)\n", sizeof(buf), metasize);
err = -EINVAL;
goto err_close;
}
if (imagesize) {
fprintf(stderr, "Invalid Seama image size: 0x%08x (should be 0)\n", imagesize);
err = -EINVAL;
goto err_close;
}
bytes = fread(buf, 1, metasize, seama);
if (bytes != metasize) {
fprintf(stderr, "Couldn't read %d B of meta\n", metasize);
err = -EIO;
goto err_close;
}
if (entity_idx < 0) {
char *end, *tmp;
printf("Meta size:\t%d\n", metasize);
printf("Image size:\t%d\n", imagesize);
end = (char *)&buf[metasize - 1];
*end = '\0';
for (tmp = (char *)buf; tmp < end && strlen(tmp); tmp += strlen(tmp) + 1) {
printf("Meta entry:\t%s\n", tmp);
}
}
oseama_info_entities(seama);
err_close:
fclose(seama);
out:
return err;
}
/**************************************************
* Create
**************************************************/
static ssize_t oseama_entity_append_file(FILE *seama, const char *in_path) {
FILE *in;
size_t bytes;
ssize_t length = 0;
uint8_t buf[128];
in = fopen(in_path, "r");
if (!in) {
fprintf(stderr, "Couldn't open %s\n", in_path);
return -EACCES;
}
while ((bytes = fread(buf, 1, sizeof(buf), in)) > 0) {
if (fwrite(buf, 1, bytes, seama) != bytes) {
fprintf(stderr, "Couldn't write %zu B to %s\n", bytes, seama_path);
length = -EIO;
break;
}
length += bytes;
}
fclose(in);
return length;
}
static ssize_t oseama_entity_append_zeros(FILE *seama, size_t length) {
uint8_t *buf;
buf = malloc(length);
if (!buf)
return -ENOMEM;
memset(buf, 0, length);
if (fwrite(buf, 1, length, seama) != length) {
fprintf(stderr, "Couldn't write %zu B to %s\n", length, seama_path);
return -EIO;
}
return length;
}
static ssize_t oseama_entity_align(FILE *seama, size_t curr_offset, size_t alignment) {
if (curr_offset & (alignment - 1)) {
size_t length = alignment - (curr_offset % alignment);
return oseama_entity_append_zeros(seama, length);
}
return 0;
}
static int oseama_entity_write_hdr(FILE *seama, size_t metasize, size_t imagesize) {
struct seama_entity_header hdr = {};
uint8_t buf[128];
size_t length = imagesize;
size_t bytes;
MD5_CTX ctx;
fseek(seama, sizeof(hdr) + metasize, SEEK_SET);
MD5_Init(&ctx);
while ((bytes = fread(buf, 1, oseama_min(sizeof(buf), length), seama)) > 0) {
MD5_Update(&ctx, buf, bytes);
length -= bytes;
}
MD5_Final(hdr.md5, &ctx);
hdr.magic = cpu_to_be32(SEAMA_MAGIC);
hdr.metasize = cpu_to_be16(metasize);
hdr.imagesize = cpu_to_be32(imagesize);
fseek(seama, 0, SEEK_SET);
bytes = fwrite(&hdr, 1, sizeof(hdr), seama);
if (bytes != sizeof(hdr)) {
fprintf(stderr, "Couldn't write Seama entity header to %s\n", seama_path);
return -EIO;
}
return 0;
}
static int oseama_entity(int argc, char **argv) {
FILE *seama;
ssize_t sbytes;
size_t curr_offset = sizeof(struct seama_entity_header);
size_t metasize = 0, imagesize = 0;
int c;
int err = 0;
if (argc < 3) {
fprintf(stderr, "No Seama file passed\n");
err = -EINVAL;
goto out;
}
seama_path = argv[2];
seama = fopen(seama_path, "w+");
if (!seama) {
fprintf(stderr, "Couldn't open %s\n", seama_path);
err = -EACCES;
goto out;
}
fseek(seama, curr_offset, SEEK_SET);
optind = 3;
while ((c = getopt(argc, argv, "m:f:b:")) != -1) {
switch (c) {
case 'm':
sbytes = fwrite(optarg, 1, strlen(optarg) + 1, seama);
if (sbytes < 0) {
fprintf(stderr, "Failed to write meta %s\n", optarg);
} else {
curr_offset += sbytes;
metasize += sbytes;
}
sbytes = oseama_entity_align(seama, curr_offset, 4);
if (sbytes < 0) {
fprintf(stderr, "Failed to append zeros\n");
} else {
curr_offset += sbytes;
metasize += sbytes;
}
break;
case 'f':
case 'b':
break;
}
}
optind = 3;
while ((c = getopt(argc, argv, "m:f:b:")) != -1) {
switch (c) {
case 'm':
break;
case 'f':
sbytes = oseama_entity_append_file(seama, optarg);
if (sbytes < 0) {
fprintf(stderr, "Failed to append file %s\n", optarg);
} else {
curr_offset += sbytes;
imagesize += sbytes;
}
break;
case 'b':
sbytes = strtol(optarg, NULL, 0) - curr_offset;
if (sbytes < 0) {
fprintf(stderr, "Current Seama entity length is 0x%zx, can't pad it with zeros to 0x%lx\n", curr_offset, strtol(optarg, NULL, 0));
} else {
sbytes = oseama_entity_append_zeros(seama, sbytes);
if (sbytes < 0) {
fprintf(stderr, "Failed to append zeros\n");
} else {
curr_offset += sbytes;
imagesize += sbytes;
}
}
break;
}
if (err)
break;
}
oseama_entity_write_hdr(seama, metasize, imagesize);
fclose(seama);
out:
return err;
}
/**************************************************
* Extract
**************************************************/
static void oseama_extract_parse_options(int argc, char **argv) {
int c;
while ((c = getopt(argc, argv, "e:o:")) != -1) {
switch (c) {
case 'e':
entity_idx = atoi(optarg);
break;
case 'o':
out_path = optarg;
break;
}
}
}
static int oseama_extract_entity(FILE *seama, FILE *out) {
struct seama_entity_header hdr;
size_t bytes, metasize, imagesize, length;
uint8_t buf[1024];
int i = 0;
int err = 0;
while ((bytes = fread(&hdr, 1, sizeof(hdr), seama)) == sizeof(hdr)) {
if (be32_to_cpu(hdr.magic) != SEAMA_MAGIC) {
fprintf(stderr, "Invalid Seama magic: 0x%08x\n", be32_to_cpu(hdr.magic));
err = -EINVAL;
break;
}
metasize = be16_to_cpu(hdr.metasize);
imagesize = be32_to_cpu(hdr.imagesize);
if (i != entity_idx) {
fseek(seama, metasize + imagesize, SEEK_CUR);
i++;
continue;
}
fseek(seama, -sizeof(hdr), SEEK_CUR);
length = sizeof(hdr) + metasize + imagesize;
while ((bytes = fread(buf, 1, oseama_min(sizeof(buf), length), seama)) > 0) {
if (fwrite(buf, 1, bytes, out) != bytes) {
fprintf(stderr, "Couldn't write %zu B to %s\n", bytes, out_path);
err = -EIO;
break;
}
length -= bytes;
}
if (length) {
fprintf(stderr, "Couldn't extract whole entity %d from %s (%zu B left)\n", entity_idx, seama_path, length);
err = -EIO;
break;
}
break;
}
return err;
}
static int oseama_extract(int argc, char **argv) {
FILE *seama;
FILE *out;
struct seama_seal_header hdr;
size_t bytes;
uint16_t metasize;
int err = 0;
if (argc < 3) {
fprintf(stderr, "No Seama file passed\n");
err = -EINVAL;
goto out;
}
seama_path = argv[2];
optind = 3;
oseama_extract_parse_options(argc, argv);
if (entity_idx < 0) {
fprintf(stderr, "No entity specified\n");
err = -EINVAL;
goto out;
} else if (!out_path) {
fprintf(stderr, "No output file specified\n");
err = -EINVAL;
goto out;
}
seama = fopen(seama_path, "r");
if (!seama) {
fprintf(stderr, "Couldn't open %s\n", seama_path);
err = -EACCES;
goto out;
}
out = fopen(out_path, "w");
if (!out) {
fprintf(stderr, "Couldn't open %s\n", out_path);
err = -EACCES;
goto err_close_seama;
}
bytes = fread(&hdr, 1, sizeof(hdr), seama);
if (bytes != sizeof(hdr)) {
fprintf(stderr, "Couldn't read %s header\n", seama_path);
err = -EIO;
goto err_close_out;
}
metasize = be16_to_cpu(hdr.metasize);
fseek(seama, metasize, SEEK_CUR);
oseama_extract_entity(seama, out);
err_close_out:
fclose(out);
err_close_seama:
fclose(seama);
out:
return err;
}
/**************************************************
* Start
**************************************************/
static void usage() {
printf("Usage:\n");
printf("\n");
printf("Info about Seama seal (container):\n");
printf("\toseama info <file> [options]\n");
printf("\t-e\t\t\t\tprint info about specified entity only\n");
printf("\n");
printf("Create Seama entity:\n");
printf("\toseama entity <file> [options]\n");
printf("\t-m meta\t\t\t\tmeta into to put in header\n");
printf("\t-f file\t\t\t\tappend content from file\n");
printf("\t-b offset\t\t\tappend zeros till reaching absolute offset\n");
printf("\n");
printf("Extract from Seama seal (container):\n");
printf("\toseama extract <file> [options]\n");
printf("\t-e\t\t\t\tindex of entity to extract\n");
printf("\t-o file\t\t\t\toutput file\n");
}
int main(int argc, char **argv) {
if (argc > 1) {
if (!strcmp(argv[1], "info"))
return oseama_info(argc, argv);
else if (!strcmp(argv[1], "entity"))
return oseama_entity(argc, argv);
else if (!strcmp(argv[1], "extract"))
return oseama_extract(argc, argv);
}
usage();
return 0;
}