OpenWrt – Rev 1

Subversion Repositories:
Rev:
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>
#include <libgen.h>
#include <stdarg.h>
#include <getopt.h>
#include <string.h>
#include <errno.h>

#include <netinet/in.h> // htonl

// Usage: mkdapimg [-p] [-m <model>] -s <sig> -i <input> -o <output>
//
// e.g.: mkdapimg -s RT3052-AP-DAP1350-3 -i sysupgrade.bin -o factory.bin
//
// If the model string <model> is not given, we will assume that
// the leading characters upto the first "-" is the model.
//
// The "-p" (patch) option is used to patch the exisiting image with the
// specified model and signature.
// The "-x" (fix) option will recalculate the payload size and checksum
// during the patch mode operation.

// The img_hdr_struct was taken from the D-Link SDK:
// DAP-1350_A1_FW1.11NA_GPL/GPL_Source_Code/Uboot/DAP-1350/httpd/header.h

#define MAX_MODEL_NAME_LEN      20
#define MAX_SIG_LEN             30
#define MAX_REGION_LEN          4
#define MAX_VERSION_LEN         12

struct img_hdr_struct {
        uint32_t checksum;
        char model[MAX_MODEL_NAME_LEN];
        char sig[MAX_SIG_LEN];
        uint8_t partition;       
        uint8_t hdr_len;
        uint8_t rsv1;
        uint8_t rsv2;    
        uint32_t flash_byte_cnt;  
} imghdr ;

char *progname;

void
perrexit(int code, char *msg)
{
        fprintf(stderr, "%s: %s: %s\n", progname, msg, strerror(errno));
        exit(code);
}

void
usage()
{
        fprintf(stderr, "usage: %s [-p] [-m model] [-r region] [-v version] -s signature -i input -o output\n", progname);
        exit(1);
}

int
main(int ac, char *av[])
{
        char model[MAX_MODEL_NAME_LEN+1];
        char signature[MAX_SIG_LEN+1];
        char region[MAX_REGION_LEN+1];
        char version[MAX_VERSION_LEN+1];
        int patchmode = 0;
        int fixmode = 0;
        int have_regionversion = 0;

        FILE *ifile, *ofile;
        int c;
        uint32_t cksum;
        uint32_t bcnt;

        progname = basename(av[0]);
        memset(model, 0, sizeof(model));
        memset(signature, 0, sizeof(signature));
        memset(region, 0, sizeof(region));
        memset(version, 0, sizeof(version));

        while ( 1 ) {
                int c;

                c = getopt(ac, av, "pxm:r:v:s:i:o:");
                if (c == -1)
                        break;

                switch (c) {
                case 'p':
                        patchmode = 1;
                        break;
                case 'x':
                        fixmode = 1;
                        break;
                case 'm':
                        if (strlen(optarg) > MAX_MODEL_NAME_LEN) {
                                fprintf(stderr, "%s: model name exceeds %d chars\n",
                                        progname, MAX_MODEL_NAME_LEN);
                                exit(1);
                        }
                        strcpy(model, optarg);
                        break;
                case 'r':
                        if (strlen(optarg) > MAX_REGION_LEN) {
                                fprintf(stderr, "%s: region exceeds %d chars\n",
                                        progname, MAX_REGION_LEN);
                                exit(1);
                        }
                        have_regionversion = 1;
                        strcpy(region, optarg);
                        break;
                case 'v':
                        if (strlen(optarg) > MAX_VERSION_LEN) {
                                fprintf(stderr, "%s: version exceeds %d chars\n",
                                        progname, MAX_VERSION_LEN);
                                exit(1);
                        }
                        have_regionversion = 1;
                        strcpy(version, optarg);
                        break;
                case 's':
                        if (strlen(optarg) > MAX_SIG_LEN) {
                                fprintf(stderr, "%s: signature exceeds %d chars\n",
                                        progname, MAX_SIG_LEN);
                                exit(1);
                        }
                        strcpy(signature, optarg);
                        break;
                case 'i':
                        if ((ifile = fopen(optarg, "r")) == NULL)
                                perrexit(1, optarg);
                        break;
                case 'o':
                        if ((ofile = fopen(optarg, "w")) == NULL)
                                perrexit(1, optarg);
                        break;
                default:
                        usage();
                }
        }

        if (signature[0] == 0 || ifile == NULL || ofile == NULL) {
                usage();
        }

        if (model[0] == 0) {
                char *p = strchr(signature, '-');
                if (p == NULL) {
                        fprintf(stderr, "%s: model name unknown\n", progname);
                        exit(1);
                }
                if (p - signature > MAX_MODEL_NAME_LEN) {
                        *p = 0;
                        fprintf(stderr, "%s: auto model name failed, string %s too long\n", progname, signature);
                        exit(1);
                }
                strncpy(model, signature, p - signature);
        }

        if (patchmode) {
                if (fread(&imghdr, sizeof(imghdr), 1, ifile) < 0)
                        perrexit(2, "fread on input");
        }

        for (bcnt = 0, cksum = 0 ; (c = fgetc(ifile)) != EOF ; bcnt++)
                cksum += c & 0xff;

        if (fseek(ifile, patchmode ? sizeof(imghdr) : 0, SEEK_SET) < 0)
                perrexit(2, "fseek on input");

        if (patchmode == 0) {
                // Fill in the header
                memset(&imghdr, 0, sizeof(imghdr));
                imghdr.checksum = htonl(cksum);
                imghdr.partition = 0 ; // don't care?
                imghdr.hdr_len = sizeof(imghdr);
                if (have_regionversion) {
                        imghdr.hdr_len += MAX_REGION_LEN;
                        imghdr.hdr_len += MAX_VERSION_LEN;
                }
                imghdr.flash_byte_cnt = htonl(bcnt);
        } else {
                if (ntohl(imghdr.checksum) != cksum) {
                        fprintf(stderr, "%s: patch mode, checksum mismatch\n",
                                progname);
                        if (fixmode) {
                                fprintf(stderr, "%s: fixing\n", progname);
                                imghdr.checksum = htonl(cksum);
                        } else
                                exit(3);
                } else if (ntohl(imghdr.flash_byte_cnt) != bcnt) {
                        fprintf(stderr, "%s: patch mode, size mismatch\n",
                                progname);
                        if (fixmode) {
                                fprintf(stderr, "%s: fixing\n", progname);
                                imghdr.flash_byte_cnt = htonl(bcnt);
                        } else
                                exit(3);
                }
        }

        strncpy(imghdr.model, model, MAX_MODEL_NAME_LEN);
        strncpy(imghdr.sig, signature, MAX_SIG_LEN);

        if (fwrite(&imghdr, sizeof(imghdr), 1, ofile) < 0)
                perrexit(2, "fwrite header on output");
        if (have_regionversion) {
                if (fwrite(&region, MAX_REGION_LEN, 1, ofile) < 0)
                        perrexit(2, "fwrite header on output");
                if (fwrite(&version, MAX_VERSION_LEN, 1, ofile) < 0)
                        perrexit(2, "fwrite header on output");
        }

        while ((c = fgetc(ifile)) != EOF) {
                if (fputc(c, ofile) == EOF)
                        perrexit(2, "fputc on output");
        }

        if (ferror(ifile))
                perrexit(2, "fgetc on input");


        fclose(ofile);
        fclose(ifile);
}