Update README.

[stg.git] / libs / smux / per_decoder.c

diff --git a/libs/smux/per_decoder.c b/libs/smux/per_decoder.c
index 16dee369624bbf28bb8957e222abe77059980d9f..a9051fb7981beea276ec9c9a873cb5bbf1115855 100644 (file)
--- a/libs/smux/per_decoder.c
+++ b/libs/smux/per_decoder.c
@@ -2,16 +2,54 @@
 #include <asn_internal.h>
 #include <per_decoder.h>
 
+/*
+ * Decode a "Production of a complete encoding", X.691#10.1.
+ * The complete encoding contains at least one byte, and is an integral
+ * multiple of 8 bytes.
+ */
 asn_dec_rval_t
-uper_decode(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td, void **sptr, const void *buffer, size_t size, int skip_bits, int unused_bits) {
-       asn_codec_ctx_t s_codec_ctx;
+uper_decode_complete(const asn_codec_ctx_t *opt_codec_ctx,
+                     const asn_TYPE_descriptor_t *td, void **sptr,
+                     const void *buffer, size_t size) {
+    asn_dec_rval_t rval;
+
+       rval = uper_decode(opt_codec_ctx, td, sptr, buffer, size, 0, 0);
+       if(rval.consumed) {
+               /*
+                * We've always given 8-aligned data,
+                * so convert bits to integral bytes.
+                */
+               rval.consumed += 7;
+               rval.consumed >>= 3;
+       } else if(rval.code == RC_OK) {
+               if(size) {
+                       if(((const uint8_t *)buffer)[0] == 0) {
+                               rval.consumed = 1;      /* 1 byte */
+                       } else {
+                               ASN_DEBUG("Expecting single zeroed byte");
+                               rval.code = RC_FAIL;
+                       }
+               } else {
+                       /* Must contain at least 8 bits. */
+                       rval.code = RC_WMORE;
+               }
+       }
+
+       return rval;
+}
+
+asn_dec_rval_t
+uper_decode(const asn_codec_ctx_t *opt_codec_ctx,
+            const asn_TYPE_descriptor_t *td, void **sptr, const void *buffer,
+            size_t size, int skip_bits, int unused_bits) {
+    asn_codec_ctx_t s_codec_ctx;
        asn_dec_rval_t rval;
        asn_per_data_t pd;
 
        if(skip_bits < 0 || skip_bits > 7
        || unused_bits < 0 || unused_bits > 7
        || (unused_bits > 0 && !size))
-               _ASN_DECODE_FAILED;
+               ASN__DECODE_FAILED;
 
        /*
         * Stack checker requires that the codec context
@@ -25,27 +63,31 @@ uper_decode(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td, void **sp
        } else {
                /* If context is not given, be security-conscious anyway */
                memset(&s_codec_ctx, 0, sizeof(s_codec_ctx));
-               s_codec_ctx.max_stack_size = _ASN_DEFAULT_STACK_MAX;
+               s_codec_ctx.max_stack_size = ASN__DEFAULT_STACK_MAX;
                opt_codec_ctx = &s_codec_ctx;
        }
 
        /* Fill in the position indicator */
+       memset(&pd, 0, sizeof(pd));
        pd.buffer = (const uint8_t *)buffer;
        pd.nboff = skip_bits;
        pd.nbits = 8 * size - unused_bits; /* 8 is CHAR_BIT from <limits.h> */
        if(pd.nboff > pd.nbits)
-               _ASN_DECODE_FAILED;
+               ASN__DECODE_FAILED;
 
        /*
         * Invoke type-specific decoder.
         */
-       if(!td->uper_decoder)
-               _ASN_DECODE_FAILED;     /* PER is not compiled in */
-       rval = td->uper_decoder(opt_codec_ctx, td, 0, sptr, &pd);
+       if(!td->op->uper_decoder)
+               ASN__DECODE_FAILED;     /* PER is not compiled in */
+       rval = td->op->uper_decoder(opt_codec_ctx, td, 0, sptr, &pd);
        if(rval.code == RC_OK) {
                /* Return the number of consumed bits */
                rval.consumed = ((pd.buffer - (const uint8_t *)buffer) << 3)
                                        + pd.nboff - skip_bits;
+               ASN_DEBUG("PER decoding consumed %ld, counted %ld",
+                       (long)rval.consumed, (long)pd.moved);
+               assert(rval.consumed == pd.moved);
        } else {
                /* PER codec is not a restartable */
                rval.consumed = 0;