added stack control to PER
diff --git a/skeletons/asn-decoder-template.c b/skeletons/asn-decoder-template.c
index c50d8b9..b428064 100644
--- a/skeletons/asn-decoder-template.c
+++ b/skeletons/asn-decoder-template.c
@@ -19,6 +19,7 @@
#include <errno.h> /* for errno */
#include <asn_application.h>
+#include <asn_internal.h> /* for _ASN_DEFAULT_STACK_MAX */
extern asn_TYPE_descriptor_t asn_DEF; /* ASN.1 type to be decoded */
#ifdef ASN_PDU_COLLECTION /* Generated by asn1c: -pdu=... */
@@ -51,11 +52,17 @@
OUT_NULL /* -onull: No pretty-printing */
} oform; /* -o<format> */
-#define DEBUG(fmt, args...) do { \
- if(!opt_debug) break; \
- fprintf(stderr, fmt, ##args); \
- fprintf(stderr, "\n"); \
-} while(0)
+/* Debug output function */
+static inline void
+DEBUG(const char *fmt, ...) {
+ va_list ap;
+ if(!opt_debug) return;
+ fprintf(stderr, "AD: ");
+ va_start(ap, fmt);
+ vfprintf(stderr, fmt, ap);
+ va_end(ap);
+ fprintf(stderr, "\n");
+}
int
main(int ac, char **av) {
@@ -131,9 +138,9 @@
break;
case 's':
opt_stack = atoi(optarg);
- if(opt_stack <= 0) {
+ if(opt_stack < 0) {
fprintf(stderr,
- "-s %s: Value greater than 0 expected\n",
+ "-s %s: Non-negative value expected\n",
optarg);
exit(EX_UNAVAILABLE);
}
@@ -164,8 +171,8 @@
" -c Check ASN.1 constraints after decoding\n"
" -d Enable debugging (-dd is even better)\n"
" -n <num> Process files <num> times\n"
- " -s <size> Set the stack usage limit\n"
- , (long)suggested_bufsize);
+ " -s <size> Set the stack usage limit (default is %d)\n"
+ , (long)suggested_bufsize, _ASN_DEFAULT_STACK_MAX);
exit(EX_USAGE);
}
@@ -250,11 +257,12 @@
return (fwrite(buffer, 1, size, fp) == size) ? 0 : -1;
}
-static char *buffer;
-static size_t buf_offset; /* Offset from the start */
+static char *buffer;
static size_t buf_len; /* Length of meaningful contents */
-static size_t buf_size; /* Allocated memory */
-static off_t buf_shifted; /* Number of bytes ever shifted */
+static size_t buf_size; /* Allocated memory */
+static size_t buf_offset; /* Offset from the start */
+static off_t buf_shifted; /* Number of bytes ever shifted */
+static int buf_nreallocs; /* Number of reallocations */
#define bufptr (buffer + buf_offset)
#define bufend (buffer + buf_offset + buf_len)
@@ -262,13 +270,13 @@
/*
* Ensure that the buffer contains at least this amount of free space.
*/
-static void buf_extend(size_t bySize) {
+static void buf_extend(const void *data2add, size_t bySize) {
DEBUG("buf_extend(%ld) { o=%ld l=%ld s=%ld }",
(long)bySize, (long)buf_offset, (long)buf_len, (long)buf_size);
if(buf_size >= (buf_offset + buf_len + bySize)) {
- return; /* Nothing to do */
+ /* Nothing to do */
} else if(bySize <= buf_offset) {
DEBUG("\tContents shifted by %ld", (long)buf_offset);
@@ -278,17 +286,22 @@
buf_offset = 0;
} else {
size_t newsize = (buf_size << 2) + bySize;
- void *p = realloc(buffer, newsize);
- if(p) {
- buffer = (char *)p;
- buf_size = newsize;
-
- DEBUG("\tBuffer reallocated to %ld", (long)newsize);
- } else {
+ void *p = malloc(newsize);
+ if(!p) {
perror("realloc()");
exit(EX_OSERR);
}
+ memcpy(p, buffer, buf_len);
+ free(buffer);
+ buffer = (char *)p;
+ buf_size = newsize;
+ buf_offset = 0;
+ DEBUG("\tBuffer reallocated to %ld, %d time",
+ (long)newsize, ++buf_nreallocs);
}
+
+ memcpy(buffer + buf_offset + buf_len, data2add, bySize);
+ buf_len += bySize;
}
static void *data_decode_from_file(asn_TYPE_descriptor_t *pduType, const char *fname, ssize_t suggested_bufsize) {
@@ -310,7 +323,7 @@
DEBUG("Processing file %s", fname);
fp = fopen(fname, "r");
} else {
- DEBUG("Processing standard input");
+ DEBUG("Processing %s", "standard input");
fname = "stdin";
fp = stdin;
}
@@ -330,8 +343,10 @@
fbuf_size = suggested_bufsize;
}
+ buf_nreallocs = 0;
buf_shifted = 0;
buf_offset = 0;
+ buf_size = 0;
buf_len = 0;
/* Pretend immediate EOF */
@@ -339,19 +354,15 @@
rval.consumed = 0;
while((rd = fread(fbuf, 1, fbuf_size, fp)) || !feof(fp)) {
- asn_per_data_t pd;
char *i_bptr;
size_t i_size;
/*
* Copy the data over, or use the original buffer.
*/
- if(buf_len) {
+ if(buf_size) {
/* Append the new data into the intermediate buffer */
- buf_extend(rd);
- memcpy(bufend, fbuf, rd);
- buf_len += rd;
-
+ buf_extend(fbuf, rd);
i_bptr = bufptr;
i_size = buf_len;
} else {
@@ -369,36 +380,35 @@
(void **)&structure, i_bptr, i_size);
break;
case INP_PER:
- pd.buffer = (uint8_t *)i_bptr;
- pd.nboff = 0;
- pd.nbits = i_size * 8;
- rval = pduType->uper_decoder(opt_codec_ctx, pduType, 0,
- (void **)&structure, &pd);
+ rval = uper_decode(opt_codec_ctx, pduType,
+ (void **)&structure, i_bptr, i_size);
break;
}
- DEBUG("decode(%ld) consumed %ld, code %d",
- (long)buf_len, (long)rval.consumed, rval.code);
+ DEBUG("decode(%ld) consumed %ld (%ld), code %d",
+ (long)buf_len, (long)rval.consumed, (long)i_size,
+ rval.code);
- if(buf_len == 0) {
+ if(buf_size == 0) {
/*
* Switch the remainder into the intermediate buffer.
*/
if(rval.code != RC_FAIL && rval.consumed < rd) {
- buf_extend(rd - rval.consumed);
- memcpy(bufend,
- fbuf + rval.consumed,
- rd - rval.consumed);
- buf_len = rd - rval.consumed;
+ buf_extend(fbuf + rval.consumed,
+ rd - rval.consumed);
+ rval.consumed = 0;
}
}
switch(rval.code) {
case RC_OK:
- DEBUG("RC_OK, finishing up");
+ DEBUG("RC_OK, finishing up with %ld",
+ (long)rval.consumed);
if(fp != stdin) fclose(fp);
return structure;
case RC_WMORE:
- DEBUG("RC_WMORE, continuing...");
+ DEBUG("RC_WMORE, continuing %ld with %ld..%ld..%ld",
+ (long)rval.consumed, (long)buf_offset,
+ (long)buf_len, (long)buf_size);
/*
* Adjust position inside the source buffer.
*/
diff --git a/skeletons/asn_codecs.h b/skeletons/asn_codecs.h
index f25a797..bd6b946 100644
--- a/skeletons/asn_codecs.h
+++ b/skeletons/asn_codecs.h
@@ -13,11 +13,13 @@
struct asn_TYPE_descriptor_s; /* Forward declaration */
/*
- * This structure defines a context that may be passed to every ASN.1 encoder
- * or decoder function.
+ * This structure defines a set of parameters that may be passed
+ * to every ASN.1 encoder or decoder function.
* WARNING: if max_stack_size member is set, and you are calling the
- * function pointers of the asn_TYPE_descriptor_t directly,
- * this structure must be ALLOCATED ON THE STACK!
+ * function pointers of the asn_TYPE_descriptor_t directly,
+ * this structure must be ALLOCATED ON THE STACK!
+ * If you can't always satisfy this requirement, use ber_decode(),
+ * xer_decode() and uper_decode() functions instead.
*/
typedef struct asn_codec_ctx_s {
/*
diff --git a/skeletons/asn_internal.h b/skeletons/asn_internal.h
index 4a86141..89c9c41 100644
--- a/skeletons/asn_internal.h
+++ b/skeletons/asn_internal.h
@@ -82,6 +82,28 @@
if(cb(" ", 4, app_key) < 0) return -1; \
} while(0)
+/*
+ * Check stack against overflow, if limit is set.
+ */
+#define _ASN_DEFAULT_STACK_MAX (30000)
+static inline int
+_ASN_STACK_OVERFLOW_CHECK(asn_codec_ctx_t *ctx) {
+ if(ctx && ctx->max_stack_size) {
+
+ /* ctx MUST be allocated on the stack */
+ ptrdiff_t usedstack = ((char *)ctx - (char *)&ctx);
+ if(usedstack > 0) usedstack = -usedstack; /* grows up! */
+
+ /* double negative required to avoid int wrap-around */
+ if(usedstack < -(ptrdiff_t)ctx->max_stack_size) {
+ ASN_DEBUG("Stack limit %ld reached",
+ (long)ctx->max_stack_size);
+ return -1;
+ }
+ }
+ return 0;
+}
+
#ifdef __cplusplus
}
#endif
diff --git a/skeletons/ber_decoder.c b/skeletons/ber_decoder.c
index bb7a090..601f66c 100644
--- a/skeletons/ber_decoder.c
+++ b/skeletons/ber_decoder.c
@@ -33,11 +33,18 @@
asn_codec_ctx_t s_codec_ctx;
/*
- * Satisfy the requirement that the codec context
+ * Stack checker requires that the codec context
* must be allocated on the stack.
*/
- if(opt_codec_ctx && opt_codec_ctx->max_stack_size) {
- s_codec_ctx = *opt_codec_ctx;
+ 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;
}
@@ -73,17 +80,8 @@
/*
* Make sure we didn't exceed the maximum stack size.
*/
- if(opt_codec_ctx && opt_codec_ctx->max_stack_size) {
- ptrdiff_t usedstack = ((char *)opt_codec_ctx - (char *)&size);
- /* double negative is required to avoid int wrap-around */
- if(usedstack > 0) usedstack = -usedstack;
- ASN_DEBUG("Current stack size %ld", -(long)usedstack);
- if(usedstack < -(ptrdiff_t)opt_codec_ctx->max_stack_size) {
- ASN_DEBUG("Stack limit %ld reached",
- (long)opt_codec_ctx->max_stack_size);
- RETURN(RC_FAIL);
- }
- }
+ if(_ASN_STACK_OVERFLOW_CHECK(opt_codec_ctx))
+ RETURN(RC_FAIL);
/*
* So what does all this implicit skip stuff mean?
diff --git a/skeletons/ber_decoder.h b/skeletons/ber_decoder.h
index fc25984..768133b 100644
--- a/skeletons/ber_decoder.h
+++ b/skeletons/ber_decoder.h
@@ -46,8 +46,8 @@
* head->last_tag_form is non-zero.
*/
asn_dec_rval_t ber_check_tags(
- struct asn_codec_ctx_s *opt_codec_ctx, /* optional context */
- struct asn_TYPE_descriptor_s *type_dsc,
+ struct asn_codec_ctx_s *opt_codec_ctx, /* codec options */
+ struct asn_TYPE_descriptor_s *type_descriptor,
asn_struct_ctx_t *opt_ctx, /* saved decoding context */
const void *ptr, size_t size,
int tag_mode, /* {-1,0,1}: IMPLICIT, no, EXPLICIT */
diff --git a/skeletons/ber_tlv_length.c b/skeletons/ber_tlv_length.c
index 49343d3..f7342e7 100644
--- a/skeletons/ber_tlv_length.c
+++ b/skeletons/ber_tlv_length.c
@@ -84,17 +84,8 @@
/*
* Make sure we didn't exceed the maximum stack size.
*/
- if(opt_codec_ctx && opt_codec_ctx->max_stack_size) {
- ptrdiff_t usedstack = ((char *)opt_codec_ctx - (char *)&size);
- /* double negative is required to avoid int wrap-around */
- if(usedstack > 0) usedstack = -usedstack;
- ASN_DEBUG("Current stack size %ld", -(long)usedstack);
- if(usedstack < -(ptrdiff_t)opt_codec_ctx->max_stack_size) {
- ASN_DEBUG("Stack limit %ld reached",
- (long)opt_codec_ctx->max_stack_size);
- return -1;
- }
- }
+ if(_ASN_STACK_OVERFLOW_CHECK(opt_codec_ctx))
+ return -1;
/*
* Determine the size of L in TLV.
diff --git a/skeletons/ber_tlv_length.h b/skeletons/ber_tlv_length.h
index d912706..3496802 100644
--- a/skeletons/ber_tlv_length.h
+++ b/skeletons/ber_tlv_length.h
@@ -31,7 +31,6 @@
* RETURN VALUES:
* Standard {-1,0,>0} convention.
*/
-struct asn_codec_ctx_s; /* Forward declaration */
ssize_t ber_skip_length(
struct asn_codec_ctx_s *opt_codec_ctx, /* optional context */
int _is_constructed, const void *bufptr, size_t size);
diff --git a/skeletons/constr_CHOICE.c b/skeletons/constr_CHOICE.c
index d3738df..33cec7e 100644
--- a/skeletons/constr_CHOICE.c
+++ b/skeletons/constr_CHOICE.c
@@ -827,6 +827,9 @@
void *st = *sptr;
int value;
+ if(_ASN_STACK_OVERFLOW_CHECK(opt_codec_ctx))
+ _ASN_DECODE_FAILED;
+
/*
* Create the target structure if it is not present already.
*/
diff --git a/skeletons/constr_SEQUENCE.c b/skeletons/constr_SEQUENCE.c
index decc56d..e4a5b08 100644
--- a/skeletons/constr_SEQUENCE.c
+++ b/skeletons/constr_SEQUENCE.c
@@ -703,7 +703,8 @@
}
tcv = xer_check_tag(buf_ptr, ch_size, xml_tag);
- ASN_DEBUG("XER/SEQUENCE: tcv = %d, ph=%d", tcv, ctx->phase);
+ ASN_DEBUG("XER/SEQUENCE: tcv = %d, ph=%d [%s]",
+ tcv, ctx->phase, xml_tag);
/* Skip the extensions section */
if(ctx->phase == 3) {
@@ -829,7 +830,13 @@
break;
}
- ASN_DEBUG("Unexpected XML tag in SEQUENCE");
+ ASN_DEBUG("Unexpected XML tag in SEQUENCE [%c%c%c%c%c%c]",
+ size>0?((const char *)buf_ptr)[0]:'.',
+ size>1?((const char *)buf_ptr)[1]:'.',
+ size>2?((const char *)buf_ptr)[2]:'.',
+ size>3?((const char *)buf_ptr)[3]:'.',
+ size>4?((const char *)buf_ptr)[4]:'.',
+ size>5?((const char *)buf_ptr)[5]:'.');
break;
}
@@ -1028,6 +1035,9 @@
(void)constraints;
+ if(_ASN_STACK_OVERFLOW_CHECK(opt_codec_ctx))
+ _ASN_DECODE_FAILED;
+
if(!st) {
st = *sptr = CALLOC(1, specs->struct_size);
if(!st) _ASN_DECODE_FAILED;
diff --git a/skeletons/constr_SET_OF.c b/skeletons/constr_SET_OF.c
index 103817b..e93c70c 100644
--- a/skeletons/constr_SET_OF.c
+++ b/skeletons/constr_SET_OF.c
@@ -864,6 +864,9 @@
int repeat = 0;
ssize_t nelems;
+ if(_ASN_STACK_OVERFLOW_CHECK(opt_codec_ctx))
+ _ASN_DECODE_FAILED;
+
/*
* Create the target structure if it is not present already.
*/
diff --git a/skeletons/per_decoder.c b/skeletons/per_decoder.c
index 55c04cb..506ad67 100644
--- a/skeletons/per_decoder.c
+++ b/skeletons/per_decoder.c
@@ -1,2 +1,38 @@
#include <asn_application.h>
+#include <asn_internal.h>
#include <per_decoder.h>
+
+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) {
+ asn_codec_ctx_t s_codec_ctx;
+ asn_per_data_t pd;
+
+ /*
+ * 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;
+ }
+
+ /* Fill in the position indicator */
+ pd.buffer = (const uint8_t *)buffer;
+ pd.nboff = 0;
+ pd.nbits = 8 * size; /* 8 is CHAR_BIT from <limits.h> */
+
+ /*
+ * Invoke type-specific decoder.
+ */
+ if(!td->uper_decoder)
+ _ASN_DECODE_FAILED; /* PER is not compiled in */
+ return td->uper_decoder(opt_codec_ctx, td, 0, sptr, &pd);
+}
+
diff --git a/skeletons/per_decoder.h b/skeletons/per_decoder.h
index 6303b3c..97eef14 100644
--- a/skeletons/per_decoder.h
+++ b/skeletons/per_decoder.h
@@ -12,6 +12,18 @@
extern "C" {
#endif
+struct asn_TYPE_descriptor_s; /* Forward declaration */
+
+/*
+ * Unaligned PER decoder of any ASN.1 type. May be invoked by the application.
+ */
+asn_dec_rval_t uper_decode(struct asn_codec_ctx_s *opt_codec_ctx,
+ struct asn_TYPE_descriptor_s *type_descriptor, /* Type to decode */
+ void **struct_ptr, /* Pointer to a target structure's pointer */
+ const void *buffer, /* Data to be decoded */
+ size_t size /* Size of data buffer */
+ );
+
/*
* Pre-computed PER constraints.
@@ -23,7 +35,6 @@
APC_EXTENSIBLE = 0x4 /* May have extension */
};
typedef struct asn_per_constraint_s {
-
enum asn_per_constraint_flags flags;
int range_bits; /* Full number of bits in the range */
int effective_bits; /* Effective bits */
@@ -35,9 +46,6 @@
asn_per_constraint_t size;
} asn_per_constraints_t;
-
-struct asn_TYPE_descriptor_s; /* Forward declaration */
-
/*
* Type of the type-specific PER decoder function.
*/
diff --git a/skeletons/per_support.c b/skeletons/per_support.c
index 9b048f0..63b39d0 100644
--- a/skeletons/per_support.c
+++ b/skeletons/per_support.c
@@ -12,7 +12,7 @@
per_get_few_bits(asn_per_data_t *pd, int nbits) {
size_t off; /* Next after last bit offset */
uint32_t accum;
- uint8_t *buf;
+ const uint8_t *buf;
if(nbits < 0 || pd->nboff + nbits > pd->nbits)
return -1;
diff --git a/skeletons/per_support.h b/skeletons/per_support.h
index a8f15fb..44f0bb4 100644
--- a/skeletons/per_support.h
+++ b/skeletons/per_support.h
@@ -15,9 +15,9 @@
* This structure describes a position inside a PER bit stream.
*/
typedef struct asn_per_data_s {
- uint8_t *buffer; /* Pointer to the octet stream */
- size_t nboff; /* Bit offset to the meaningful bit */
- size_t nbits; /* Number of bits in the stream */
+ const uint8_t *buffer; /* Pointer to the octet stream */
+ size_t nboff; /* Bit offset to the meaningful bit */
+ size_t nbits; /* Number of bits in the stream */
} asn_per_data_t;
/*
diff --git a/skeletons/xer_decoder.c b/skeletons/xer_decoder.c
index e48a5ed..2b3f16a 100644
--- a/skeletons/xer_decoder.c
+++ b/skeletons/xer_decoder.c
@@ -16,11 +16,18 @@
asn_codec_ctx_t s_codec_ctx;
/*
- * Satisfy the requirement that the codec context
+ * Stack checker requires that the codec context
* must be allocated on the stack.
*/
- if(opt_codec_ctx && opt_codec_ctx->max_stack_size) {
- s_codec_ctx = *opt_codec_ctx;
+ 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;
}
diff --git a/skeletons/xer_decoder.h b/skeletons/xer_decoder.h
index 349f349..cf0d846 100644
--- a/skeletons/xer_decoder.h
+++ b/skeletons/xer_decoder.h
@@ -14,13 +14,13 @@
struct asn_TYPE_descriptor_s; /* Forward declaration */
/*
- * The XER decoder of any type. May be invoked by the application.
+ * The XER decoder of any ASN.1 type. May be invoked by the application.
*/
asn_dec_rval_t xer_decode(struct asn_codec_ctx_s *opt_codec_ctx,
struct asn_TYPE_descriptor_s *type_descriptor,
void **struct_ptr, /* Pointer to a target structure's pointer */
const void *buffer, /* Data to be decoded */
- size_t size /* Size of that buffer */
+ size_t size /* Size of data buffer */
);
/*