]> git.stg.codes - stg.git/blobdiff - projects/stargazer/plugins/other/snmp/asn1/ber_decoder.c
snma agent -> smux
[stg.git] / projects / stargazer / plugins / other / snmp / asn1 / ber_decoder.c
diff --git a/projects/stargazer/plugins/other/snmp/asn1/ber_decoder.c b/projects/stargazer/plugins/other/snmp/asn1/ber_decoder.c
deleted file mode 100644 (file)
index 601f66c..0000000
+++ /dev/null
@@ -1,283 +0,0 @@
-/*-
- * Copyright (c) 2003, 2004 Lev Walkin <vlm@lionet.info>. All rights reserved.
- * Redistribution and modifications are permitted subject to BSD license.
- */
-#include <asn_internal.h>
-
-#undef ADVANCE
-#define        ADVANCE(num_bytes)      do {                                    \
-               size_t num = num_bytes;                                 \
-               ptr = ((const char *)ptr) + num;                        \
-               size -= num;                                            \
-               consumed_myself += num;                                 \
-       } while(0)
-#undef RETURN
-#define        RETURN(_code)   do {                                            \
-               asn_dec_rval_t rval;                                    \
-               rval.code = _code;                                      \
-               if(opt_ctx) opt_ctx->step = step; /* Save context */    \
-               if(_code == RC_OK || opt_ctx)                           \
-                       rval.consumed = consumed_myself;                \
-               else                                                    \
-                       rval.consumed = 0;      /* Context-free */      \
-               return rval;                                            \
-       } while(0)
-
-/*
- * The BER decoder of any type.
- */
-asn_dec_rval_t
-ber_decode(asn_codec_ctx_t *opt_codec_ctx,
-       asn_TYPE_descriptor_t *type_descriptor,
-       void **struct_ptr, const void *ptr, size_t size) {
-       asn_codec_ctx_t s_codec_ctx;
-
-       /*
-        * Stack checker requires that the codec context
-        * must be allocated on the stack.
-        */
-       if(opt_codec_ctx) {
-               if(opt_codec_ctx->max_stack_size) {
-                       s_codec_ctx = *opt_codec_ctx;
-                       opt_codec_ctx = &s_codec_ctx;
-               }
-       } 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;
-               opt_codec_ctx = &s_codec_ctx;
-       }
-
-       /*
-        * Invoke type-specific decoder.
-        */
-       return type_descriptor->ber_decoder(opt_codec_ctx, type_descriptor,
-               struct_ptr,     /* Pointer to the destination structure */
-               ptr, size,      /* Buffer and its size */
-               0               /* Default tag mode is 0 */
-               );
-}
-
-/*
- * Check the set of <TL<TL<TL...>>> tags matches the definition.
- */
-asn_dec_rval_t
-ber_check_tags(asn_codec_ctx_t *opt_codec_ctx,
-               asn_TYPE_descriptor_t *td, asn_struct_ctx_t *opt_ctx,
-               const void *ptr, size_t size, int tag_mode, int last_tag_form,
-               ber_tlv_len_t *last_length, int *opt_tlv_form) {
-       ssize_t consumed_myself = 0;
-       ssize_t tag_len;
-       ssize_t len_len;
-       ber_tlv_tag_t tlv_tag;
-       ber_tlv_len_t tlv_len;
-       ber_tlv_len_t limit_len = -1;
-       int expect_00_terminators = 0;
-       int tlv_constr = -1;    /* If CHOICE, opt_tlv_form is not given */
-       int step = opt_ctx ? opt_ctx->step : 0; /* Where we left previously */
-       int tagno;
-
-       /*
-        * Make sure we didn't exceed the maximum stack size.
-        */
-       if(_ASN_STACK_OVERFLOW_CHECK(opt_codec_ctx))
-               RETURN(RC_FAIL);
-
-       /*
-        * So what does all this implicit skip stuff mean?
-        * Imagine two types,
-        *      A ::= [5] IMPLICIT      T
-        *      B ::= [2] EXPLICIT      T
-        * Where T is defined as
-        *      T ::= [4] IMPLICIT SEQUENCE { ... }
-        * 
-        * Let's say, we are starting to decode type A, given the
-        * following TLV stream: <5> <0>. What does this mean?
-        * It means that the type A contains type T which is,
-        * in turn, empty.
-        * Remember though, that we are still in A. We cannot
-        * just pass control to the type T decoder. Why? Because
-        * the type T decoder expects <4> <0>, not <5> <0>.
-        * So, we must make sure we are going to receive <5> while
-        * still in A, then pass control to the T decoder, indicating
-        * that the tag <4> was implicitly skipped. The decoder of T
-        * hence will be prepared to treat <4> as valid tag, and decode
-        * it appropriately.
-        */
-
-       tagno = step    /* Continuing where left previously */
-               + (tag_mode==1?-1:0)
-               ;
-       ASN_DEBUG("ber_check_tags(%s, size=%ld, tm=%d, step=%d, tagno=%d)",
-               td->name, (long)size, tag_mode, step, tagno);
-       /* assert(td->tags_count >= 1) May not be the case for CHOICE or ANY */
-
-       if(tag_mode == 0 && tagno == td->tags_count) {
-               /*
-                * This must be the _untagged_ ANY type,
-                * which outermost tag isn't known in advance.
-                * Fetch the tag and length separately.
-                */
-               tag_len = ber_fetch_tag(ptr, size, &tlv_tag);
-               switch(tag_len) {
-               case -1: RETURN(RC_FAIL);
-               case 0: RETURN(RC_WMORE);
-               }
-               tlv_constr = BER_TLV_CONSTRUCTED(ptr);
-               len_len = ber_fetch_length(tlv_constr,
-                       (const char *)ptr + tag_len, size - tag_len, &tlv_len);
-               switch(len_len) {
-               case -1: RETURN(RC_FAIL);
-               case 0: RETURN(RC_WMORE);
-               }
-               ASN_DEBUG("Advancing %ld in ANY case",
-                       (long)(tag_len + len_len));
-               ADVANCE(tag_len + len_len);
-       } else {
-               assert(tagno < td->tags_count); /* At least one loop */
-       }
-       for((void)tagno; tagno < td->tags_count; tagno++, step++) {
-
-               /*
-                * Fetch and process T from TLV.
-                */
-               tag_len = ber_fetch_tag(ptr, size, &tlv_tag);
-                       ASN_DEBUG("Fetching tag from {%p,%ld}: "
-                               "len %ld, step %d, tagno %d got %s",
-                               ptr, (long)size,
-                               (long)tag_len, step, tagno,
-                               ber_tlv_tag_string(tlv_tag));
-               switch(tag_len) {
-               case -1: RETURN(RC_FAIL);
-               case 0: RETURN(RC_WMORE);
-               }
-
-               tlv_constr = BER_TLV_CONSTRUCTED(ptr);
-
-               /*
-                * If {I}, don't check anything.
-                * If {I,B,C}, check B and C unless we're at I.
-                */
-               if(tag_mode != 0 && step == 0) {
-                       /*
-                        * We don't expect tag to match here.
-                        * It's just because we don't know how the tag
-                        * is supposed to look like.
-                        */
-               } else {
-                   assert(tagno >= 0); /* Guaranteed by the code above */
-                   if(tlv_tag != td->tags[tagno]) {
-                       /*
-                        * Unexpected tag. Too bad.
-                        */
-                       ASN_DEBUG("Expected: %s, "
-                               "expectation failed (tn=%d, tm=%d)",
-                               ber_tlv_tag_string(td->tags[tagno]),
-                               tagno, tag_mode
-                       );
-                       RETURN(RC_FAIL);
-                   }
-               }
-
-               /*
-                * Attention: if there are more tags expected,
-                * ensure that the current tag is presented
-                * in constructed form (it contains other tags!).
-                * If this one is the last one, check that the tag form
-                * matches the one given in descriptor.
-                */
-               if(tagno < (td->tags_count - 1)) {
-                       if(tlv_constr == 0) {
-                               ASN_DEBUG("tlv_constr = %d, expfail",
-                                       tlv_constr);
-                               RETURN(RC_FAIL);
-                       }
-               } else {
-                       if(last_tag_form != tlv_constr
-                       && last_tag_form != -1) {
-                               ASN_DEBUG("last_tag_form %d != %d",
-                                       last_tag_form, tlv_constr);
-                               RETURN(RC_FAIL);
-                       }
-               }
-
-               /*
-                * Fetch and process L from TLV.
-                */
-               len_len = ber_fetch_length(tlv_constr,
-                       (const char *)ptr + tag_len, size - tag_len, &tlv_len);
-               ASN_DEBUG("Fetchinig len = %ld", (long)len_len);
-               switch(len_len) {
-               case -1: RETURN(RC_FAIL);
-               case 0: RETURN(RC_WMORE);
-               }
-
-               /*
-                * FIXME
-                * As of today, the chain of tags
-                * must either contain several indefinite length TLVs,
-                * or several definite length ones.
-                * No mixing is allowed.
-                */
-               if(tlv_len == -1) {
-                       /*
-                        * Indefinite length.
-                        */
-                       if(limit_len == -1) {
-                               expect_00_terminators++;
-                       } else {
-                               ASN_DEBUG("Unexpected indefinite length "
-                                       "in a chain of definite lengths");
-                               RETURN(RC_FAIL);
-                       }
-                       ADVANCE(tag_len + len_len);
-                       continue;
-               } else {
-                       if(expect_00_terminators) {
-                               ASN_DEBUG("Unexpected definite length "
-                                       "in a chain of indefinite lengths");
-                               RETURN(RC_FAIL);
-                       }
-               }
-
-               /*
-                * Check that multiple TLVs specify ever decreasing length,
-                * which is consistent.
-                */
-               if(limit_len == -1) {
-                       limit_len    = tlv_len + tag_len + len_len;
-                       if(limit_len < 0) {
-                               /* Too great tlv_len value? */
-                               RETURN(RC_FAIL);
-                       }
-               } else if(limit_len != tlv_len + tag_len + len_len) {
-                       /*
-                        * Inner TLV specifies length which is inconsistent
-                        * with the outer TLV's length value.
-                        */
-                       ASN_DEBUG("Outer TLV is %ld and inner is %ld",
-                               (long)limit_len, (long)tlv_len);
-                       RETURN(RC_FAIL);
-               }
-
-               ADVANCE(tag_len + len_len);
-
-               limit_len -= (tag_len + len_len);
-               if((ssize_t)size > limit_len) {
-                       /*
-                        * Make sure that we won't consume more bytes
-                        * from the parent frame than the inferred limit.
-                        */
-                       size = limit_len;
-               }
-       }
-
-       if(opt_tlv_form)
-               *opt_tlv_form = tlv_constr;
-       if(expect_00_terminators)
-               *last_length = -expect_00_terminators;
-       else
-               *last_length = tlv_len;
-
-       RETURN(RC_OK);
-}