otrx: extract shared code opening & parsing TRX format

This avoids some code duplication.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>

diff --git a/src/otrx.c b/src/otrx.c
index af6e905cdc815bb3a88fbfc7d4125cbc516d718e..7f661cacdc7db3039a412e6420c5a298a17d01c0 100644 (file)
--- a/src/otrx.c
+++ b/src/otrx.c
@@ -42,6 +42,11 @@ struct trx_header {
        uint32_t offset[3];
 };
 
+struct otrx_ctx {
+       FILE *fp;
+       struct trx_header hdr;
+};
+
 char *trx_path;
 size_t trx_offset = 0;
 char *partition[TRX_MAX_PARTS] = {};
@@ -169,6 +174,54 @@ static void otrx_close(FILE *fp) {
                fclose(fp);
 }
 
+static int otrx_open_parse(const char *pathname, const char *mode,
+                          struct otrx_ctx *otrx)
+{
+       size_t length;
+       size_t bytes;
+       int err;
+
+       otrx->fp = otrx_open(pathname, mode);
+       if (!otrx->fp) {
+               fprintf(stderr, "Couldn't open %s\n", pathname);
+               err = -EACCES;
+               goto err_out;
+       }
+
+       if (trx_offset && otrx_skip(otrx->fp, trx_offset)) {
+               fprintf(stderr, "Couldn't skip first %zd B\n", trx_offset);
+               err = -EIO;
+               goto err_close;
+       }
+
+       bytes = fread(&otrx->hdr, 1, sizeof(otrx->hdr), otrx->fp);
+       if (bytes != sizeof(otrx->hdr)) {
+               fprintf(stderr, "Couldn't read %s header\n", pathname);
+               err = -EIO;
+               goto err_close;
+       }
+
+       if (le32_to_cpu(otrx->hdr.magic) != TRX_MAGIC) {
+               fprintf(stderr, "Invalid TRX magic: 0x%08x\n", le32_to_cpu(otrx->hdr.magic));
+               err =  -EINVAL;
+               goto err_close;
+       }
+
+       length = le32_to_cpu(otrx->hdr.length);
+       if (length < sizeof(otrx->hdr)) {
+               fprintf(stderr, "Length read from TRX too low (%zu B)\n", length);
+               err = -EINVAL;
+               goto err_close;
+       }
+
+       return 0;
+
+err_close:
+       otrx_close(otrx->fp);
+err_out:
+       return err;
+}
+
 /**************************************************
  * Check
  **************************************************/
@@ -186,8 +239,7 @@ static void otrx_check_parse_options(int argc, char **argv) {
 }
 
 static int otrx_check(int argc, char **argv) {
-       FILE *trx;
-       struct trx_header hdr;
+       struct otrx_ctx otrx = { };
        size_t bytes, length;
        uint8_t buf[1024];
        uint32_t crc32;
@@ -203,43 +255,17 @@ static int otrx_check(int argc, char **argv) {
        optind = 3;
        otrx_check_parse_options(argc, argv);
 
-       trx = otrx_open(trx_path, "r");
-       if (!trx) {
-               fprintf(stderr, "Couldn't open %s\n", trx_path);
+       err = otrx_open_parse(trx_path, "r", &otrx);
+       if (err) {
+               fprintf(stderr, "Couldn't open & parse %s: %d\n", trx_path, err);
                err = -EACCES;
                goto out;
        }
 
-       if (trx_offset && otrx_skip(trx, trx_offset)) {
-               fprintf(stderr, "Couldn't skip first %zd B\n", trx_offset);
-               err =  -EIO;
-               goto err_close;
-       }
-
-       bytes = fread(&hdr, 1, sizeof(hdr), trx);
-       if (bytes != sizeof(hdr)) {
-               fprintf(stderr, "Couldn't read %s header\n", trx_path);
-               err =  -EIO;
-               goto err_close;
-       }
-
-       if (le32_to_cpu(hdr.magic) != TRX_MAGIC) {
-               fprintf(stderr, "Invalid TRX magic: 0x%08x\n", le32_to_cpu(hdr.magic));
-               err =  -EINVAL;
-               goto err_close;
-       }
-
-       length = le32_to_cpu(hdr.length);
-       if (length < sizeof(hdr)) {
-               fprintf(stderr, "Length read from TRX too low (%zu B)\n", length);
-               err = -EINVAL;
-               goto err_close;
-       }
-
        crc32 = 0xffffffff;
-       crc32 = otrx_crc32(crc32, (uint8_t *)&hdr + TRX_FLAGS_OFFSET, sizeof(hdr) - TRX_FLAGS_OFFSET);
-       length -= sizeof(hdr);
-       while ((bytes = fread(buf, 1, otrx_min(sizeof(buf), length), trx)) > 0) {
+       crc32 = otrx_crc32(crc32, (uint8_t *)&otrx.hdr + TRX_FLAGS_OFFSET, sizeof(otrx.hdr) - TRX_FLAGS_OFFSET);
+       length = le32_to_cpu(otrx.hdr.length) - sizeof(otrx.hdr);
+       while ((bytes = fread(buf, 1, otrx_min(sizeof(buf), length), otrx.fp)) > 0) {
                crc32 = otrx_crc32(crc32, buf, bytes);
                length -= bytes;
        }
@@ -250,16 +276,16 @@ static int otrx_check(int argc, char **argv) {
                goto err_close;
        }
 
-       if (crc32 != le32_to_cpu(hdr.crc32)) {
-               fprintf(stderr, "Invalid data crc32: 0x%08x instead of 0x%08x\n", crc32, le32_to_cpu(hdr.crc32));
+       if (crc32 != le32_to_cpu(otrx.hdr.crc32)) {
+               fprintf(stderr, "Invalid data crc32: 0x%08x instead of 0x%08x\n", crc32, le32_to_cpu(otrx.hdr.crc32));
                err =  -EINVAL;
                goto err_close;
        }
 
-       printf("Found a valid TRX version %d\n", le32_to_cpu(hdr.version));
+       printf("Found a valid TRX version %d\n", le32_to_cpu(otrx.hdr.version));
 
 err_close:
-       otrx_close(trx);
+       otrx_close(otrx.fp);
 out:
        return err;
 }
@@ -541,41 +567,25 @@ out:
 }
 
 static int otrx_extract(int argc, char **argv) {
-       FILE *trx;
-       struct trx_header hdr;
-       size_t bytes;
+       struct otrx_ctx otrx = { };
        int i;
        int err = 0;
 
        if (argc < 3) {
                fprintf(stderr, "No TRX file passed\n");
                err = -EINVAL;
-               goto out;
+               goto err_out;
        }
        trx_path = argv[2];
 
        optind = 3;
        otrx_extract_parse_options(argc, argv);
 
-       trx = fopen(trx_path, "r");
-       if (!trx) {
-               fprintf(stderr, "Couldn't open %s\n", trx_path);
+       err = otrx_open_parse(trx_path, "r", &otrx);
+       if (err) {
+               fprintf(stderr, "Couldn't open & parse %s: %d\n", trx_path, err);
                err = -EACCES;
-               goto out;
-       }
-
-       fseek(trx, trx_offset, SEEK_SET);
-       bytes = fread(&hdr, 1, sizeof(hdr), trx);
-       if (bytes != sizeof(hdr)) {
-               fprintf(stderr, "Couldn't read %s header\n", trx_path);
-               err =  -EIO;
-               goto err_close;
-       }
-
-       if (le32_to_cpu(hdr.magic) != TRX_MAGIC) {
-               fprintf(stderr, "Invalid TRX magic: 0x%08x\n", le32_to_cpu(hdr.magic));
-               err =  -EINVAL;
-               goto err_close;
+               goto err_out;
        }
 
        for (i = 0; i < TRX_MAX_PARTS; i++) {
@@ -583,22 +593,21 @@ static int otrx_extract(int argc, char **argv) {
 
                if (!partition[i])
                        continue;
-               if (!hdr.offset[i]) {
+               if (!otrx.hdr.offset[i]) {
                        printf("TRX doesn't contain partition %d, can't extract %s\n", i + 1, partition[i]);
                        continue;
                }
 
-               if (i + 1 >= TRX_MAX_PARTS || !hdr.offset[i + 1])
-                       length = le32_to_cpu(hdr.length) - le32_to_cpu(hdr.offset[i]);
+               if (i + 1 >= TRX_MAX_PARTS || !otrx.hdr.offset[i + 1])
+                       length = le32_to_cpu(otrx.hdr.length) - le32_to_cpu(otrx.hdr.offset[i]);
                else
-                       length = le32_to_cpu(hdr.offset[i + 1]) - le32_to_cpu(hdr.offset[i]);
+                       length = le32_to_cpu(otrx.hdr.offset[i + 1]) - le32_to_cpu(otrx.hdr.offset[i]);
 
-               otrx_extract_copy(trx, trx_offset + le32_to_cpu(hdr.offset[i]), length, partition[i]);
+               otrx_extract_copy(otrx.fp, trx_offset + le32_to_cpu(otrx.hdr.offset[i]), length, partition[i]);
        }
 
-err_close:
-       fclose(trx);
-out:
+       otrx_close(otrx.fp);
+err_out:
        return err;
 }