otrx: optimize memory usage by function checking TRX CRC

Allocating huge buffer for the whole TRX wasn't too optimal.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
SVN-Revision: 46078

diff --git a/package/utils/otrx/src/otrx.c b/package/utils/otrx/src/otrx.c
index 213f9599476d7331b4d64aa165ed4b34f09e2764..11db426a1df7036c14705f8b931dc9999eda401a 100644 (file)
--- a/package/utils/otrx/src/otrx.c
+++ b/package/utils/otrx/src/otrx.c
@@ -44,6 +44,10 @@ char *trx_path;
 size_t trx_offset = 0;
 char *partition[TRX_MAX_PARTS] = {};
 
+static inline size_t otrx_min(size_t x, size_t y) {
+       return x < y ? x : y;
+}
+
 /**************************************************
  * CRC32
  **************************************************/
@@ -147,8 +151,9 @@ static int otrx_check(int argc, char **argv) {
        FILE *trx;
        struct trx_header hdr;
        size_t bytes, length;
-       uint8_t *buf;
+       uint8_t buf[1024];
        uint32_t crc32;
+       int i;
        int err = 0;
 
        if (argc < 3) {
@@ -189,32 +194,29 @@ static int otrx_check(int argc, char **argv) {
                goto err_close;
        }
 
-       buf = malloc(length);
-       if (!buf) {
-               fprintf(stderr, "Couldn't alloc %zd B buffer\n", length);
-               err =  -ENOMEM;
-               goto err_close;
+       crc32 = 0xffffffff;
+       fseek(trx, trx_offset + TRX_FLAGS_OFFSET, SEEK_SET);
+       length -= TRX_FLAGS_OFFSET;
+       while ((bytes = fread(buf, 1, otrx_min(sizeof(buf), length), trx)) > 0) {
+               for (i = 0; i < bytes; i++)
+                       crc32 = crc32_tbl[(crc32 ^ buf[i]) & 0xff] ^ (crc32 >> 8);
+               length -= bytes;
        }
 
-       fseek(trx, trx_offset, SEEK_SET);
-       bytes = fread(buf, 1, length, trx);
-       if (bytes != length) {
-               fprintf(stderr, "Couldn't read %zd B of data from %s\n", length, trx_path);
-               err =  -ENOMEM;
-               goto err_free_buf;
+       if (length) {
+               fprintf(stderr, "Couldn't read last %zd B of data from %s\n", length, trx_path);
+               err = -EIO;
+               goto err_close;
        }
 
-       crc32 = otrx_crc32(buf + TRX_FLAGS_OFFSET, length - TRX_FLAGS_OFFSET);
        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));
                err =  -EINVAL;
-               goto err_free_buf;
+               goto err_close;
        }
 
        printf("Found a valid TRX version %d\n", le32_to_cpu(hdr.version));
 
-err_free_buf:
-       free(buf);
 err_close:
        fclose(trx);
 out: