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authorPaul Selkirk <paul@psgd.org>2018-02-27 17:51:48 +0100
committerPaul Selkirk <paul@psgd.org>2018-02-27 17:51:48 +0100
commit8529d05262aa636a1bb701e19a34c371d49a6fe4 (patch)
treea8d117f6790945c6d8bc812a9ee47f969291ce44 /xdr.c
parent894181009ad3002d84d2ce6ea74bbd5aea068999 (diff)
Refactor XDR code, add support for fixed-length opaque data.
Diffstat (limited to 'xdr.c')
-rw-r--r--xdr.c222
1 files changed, 90 insertions, 132 deletions
diff --git a/xdr.c b/xdr.c
index e7c81b2..9a958ac 100644
--- a/xdr.c
+++ b/xdr.c
@@ -2,8 +2,9 @@
* xdr.c
* -----
* Serialization/deserialization routines, using XDR (RFC 4506) encoding.
+ * These functions are not part of the public libhal API.
*
- * Copyright (c) 2016, NORDUnet A/S All rights reserved.
+ * Copyright (c) 2016-2018, NORDUnet A/S All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
@@ -38,7 +39,7 @@
#include <string.h> /* memcpy, memset */
#include "hal.h"
-#include "hal_internal.h"
+#include "hal_internal.h" /* htonl/ntohl */
#include "xdr_internal.h"
/* encode/decode_int. This covers int, unsigned int, enum, and bool types,
@@ -61,7 +62,8 @@ hal_error_t hal_xdr_encode_int(uint8_t ** const outbuf, const uint8_t * const li
return HAL_OK;
}
-hal_error_t hal_xdr_decode_int(const uint8_t ** const inbuf, const uint8_t * const limit, uint32_t *value)
+/* decode an integer value without advancing the input pointer */
+hal_error_t hal_xdr_decode_int_peek(const uint8_t ** const inbuf, const uint8_t * const limit, uint32_t *value)
{
/* arg checks */
if (inbuf == NULL || *inbuf == NULL || limit == NULL || value == NULL)
@@ -72,44 +74,38 @@ hal_error_t hal_xdr_decode_int(const uint8_t ** const inbuf, const uint8_t * con
return HAL_ERROR_XDR_BUFFER_OVERFLOW;
*value = ntohl(**(uint32_t **)inbuf);
- *inbuf += sizeof(*value);
return HAL_OK;
}
-/* Undo the last decode_int - roll back the input pointer.
- */
-hal_error_t hal_xdr_undecode_int(const uint8_t ** const inbuf)
+/* decode an integer value the regular way */
+hal_error_t hal_xdr_decode_int(const uint8_t ** const inbuf, const uint8_t * const limit, uint32_t *value)
{
- if (inbuf == NULL || *inbuf == NULL)
- return HAL_ERROR_BAD_ARGUMENTS;
+ hal_error_t err;
- *inbuf -= sizeof(uint32_t);
- return HAL_OK;
+ if ((err = hal_xdr_decode_int_peek(inbuf, limit, value)) == HAL_OK)
+ *inbuf += sizeof(*value);
+
+ return err;
}
-/* encode/decode_buffer. This covers variable-length string and opaque types.
- * The data is preceded by a 4-byte length word (encoded as above), and padded
- * to a multiple of 4 bytes as necessary.
+/* encode/decode_fixed_opaque. This covers fixed-length string and opaque types.
+ * The data is padded to a multiple of 4 bytes as necessary.
*/
-hal_error_t hal_xdr_encode_buffer(uint8_t **outbuf, const uint8_t * const limit, const uint8_t *value, const uint32_t len)
+hal_error_t hal_xdr_encode_fixed_opaque(uint8_t ** const outbuf, const uint8_t * const limit, const uint8_t * const value, const size_t len)
{
- hal_error_t ret;
+ if (len == 0)
+ return HAL_OK;
/* arg checks */
- if (outbuf == NULL || *outbuf == NULL || limit == NULL ||
- (value == NULL && len != 0))
+ if (outbuf == NULL || *outbuf == NULL || limit == NULL || value == NULL)
return HAL_ERROR_BAD_ARGUMENTS;
/* buffer overflow check */
- if (limit - *outbuf < (ptrdiff_t)(((len + 3) & ~3) + sizeof(len)))
+ if (limit - *outbuf < (ptrdiff_t)((len + 3) & ~3))
return HAL_ERROR_XDR_BUFFER_OVERFLOW;
- /* encode length */
- if ((ret = hal_xdr_encode_int(outbuf, limit, len)) != HAL_OK)
- return ret;
-
- /* write the string or opaque data */
+ /* write the data */
memcpy(*outbuf, value, len);
*outbuf += len;
@@ -123,139 +119,101 @@ hal_error_t hal_xdr_encode_buffer(uint8_t **outbuf, const uint8_t * const limit,
return HAL_OK;
}
-/* This version returns a pointer to the data in the input buffer.
- * It is used in the rpc server.
- */
-hal_error_t hal_xdr_decode_buffer_in_place(const uint8_t **inbuf, const uint8_t * const limit, const uint8_t ** const value, uint32_t * const len)
+hal_error_t hal_xdr_decode_fixed_opaque_ptr(const uint8_t ** const inbuf, const uint8_t * const limit, const uint8_t ** const value, const size_t len)
{
- hal_error_t ret;
- uint32_t xdr_len;
- const uint8_t *orig_inbuf = *inbuf;
-
/* arg checks */
- if (inbuf == NULL || *inbuf == NULL || limit == NULL || value == NULL || len == NULL)
+ if (inbuf == NULL || *inbuf == NULL || limit == NULL || value == NULL)
return HAL_ERROR_BAD_ARGUMENTS;
- /* decode the length */
- if ((ret = hal_xdr_decode_int(inbuf, limit, &xdr_len)) != HAL_OK)
- return ret;
-
- /* input and output buffer overflow checks vs decoded length */
-
- /* decoded length is past the end of the input buffer;
- * we're probably out of sync, but nothing we can do now
- */
- if (limit - *inbuf < (ptrdiff_t)xdr_len) {
- /* undo read of length */
- *inbuf = orig_inbuf;
+ /* buffer overflow check */
+ if (limit - *inbuf < (ptrdiff_t)len)
return HAL_ERROR_XDR_BUFFER_OVERFLOW;
- }
- /* return a pointer to the string or opaque data */
+ /* return a pointer to the data */
*value = *inbuf;
- *len = xdr_len;
/* update the buffer pointer, skipping any padding bytes */
- *inbuf += (xdr_len + 3) & ~3;
+ *inbuf += ((len + 3) & ~3);
return HAL_OK;
}
-/* This version copies the data to the user-supplied buffer.
- * It is used in the rpc client.
- */
-hal_error_t hal_xdr_decode_buffer(const uint8_t **inbuf, const uint8_t * const limit, uint8_t * const value, uint32_t * const len)
+hal_error_t hal_xdr_decode_fixed_opaque(const uint8_t ** const inbuf, const uint8_t * const limit, uint8_t * const value, const size_t len)
{
- if (inbuf == NULL || value == NULL || len == NULL)
- return HAL_ERROR_BAD_ARGUMENTS;
+ const uint8_t *p;
+ hal_error_t err;
- hal_error_t ret;
- const uint8_t *vptr;
- const uint8_t *orig_inbuf = *inbuf;
- uint32_t xdr_len;
+ /* get and advance the input data pointer */
+ if ((err = hal_xdr_decode_fixed_opaque_ptr(inbuf, limit, &p, len)) == HAL_OK)
+ /* read the data */
+ memcpy(value, p, len);
+
+ return err;
+}
- if ((ret = hal_xdr_decode_buffer_in_place(inbuf, limit, &vptr, &xdr_len)) != HAL_OK)
- return ret;
+/* encode/decode_variable_opaque. This covers variable-length string and opaque types.
+ * The data is preceded by a 4-byte length word (encoded as above), and padded
+ * to a multiple of 4 bytes as necessary.
+ */
- if (*len < xdr_len) {
- /* user buffer is too small, undo read of length */
- *inbuf = orig_inbuf;
- ret = HAL_ERROR_XDR_BUFFER_OVERFLOW;
- }
- else {
- memcpy(value, vptr, xdr_len);
- }
+hal_error_t hal_xdr_encode_variable_opaque(uint8_t ** const outbuf, const uint8_t * const limit, const uint8_t * const value, const size_t len)
+{
+ hal_error_t err;
- *len = xdr_len;
+ /* encode length */
+ if ((err = hal_xdr_encode_int(outbuf, limit, (uint32_t)len)) == HAL_OK) {
+ /* encode data */
+ if ((err = hal_xdr_encode_fixed_opaque(outbuf, limit, value, len)) != HAL_OK)
+ /* undo write of length */
+ *outbuf -= 4;
+ }
- return ret;
+ return err;
}
-/* ---------------------------------------------------------------- */
-
-#ifdef TEST
-static void hexdump(uint8_t *buf, uint32_t len)
+/* This version returns a pointer to the data in the input buffer.
+ * It is used in the rpc server.
+ */
+hal_error_t hal_xdr_decode_variable_opaque_ptr(const uint8_t ** const inbuf, const uint8_t * const limit, const uint8_t ** const value, size_t * const len)
{
- for (uint32_t i = 0; i < len; ++i)
- printf("%02x%c", buf[i], ((i & 0x07) == 0x07) ? '\n' : ' ');
- if ((len & 0x07) != 0)
- printf("\n");
+ hal_error_t err;
+ uint32_t xdr_len;
+
+ /* arg checks */
+ if (len == NULL)
+ return HAL_ERROR_BAD_ARGUMENTS;
+
+ /* read length */
+ if ((err = hal_xdr_decode_int(inbuf, limit, &xdr_len)) == HAL_OK) {
+ /* get the data pointer */
+ if ((err = hal_xdr_decode_fixed_opaque_ptr(inbuf, limit, value, xdr_len)) == HAL_OK)
+ *len = xdr_len;
+ else
+ /* undo read of length */
+ *inbuf -= 4;
+ }
+
+ return err;
}
-int main(int argc, char *argv[])
+/* This version copies the data to the user-supplied buffer.
+ * It is used in the rpc client.
+ */
+hal_error_t hal_xdr_decode_variable_opaque(const uint8_t ** const inbuf, const uint8_t * const limit, uint8_t * const value, size_t * const len)
{
- uint32_t i;
- uint8_t buf[64] = {0};
- uint8_t *bufptr = buf, *readptr;
- uint8_t *limit = buf + sizeof(buf);
- hal_error_t ret;
- uint8_t alphabet[] = "abcdefghijklmnopqrstuvwxyz";
- uint8_t readbuf[64] = {0};
-
- printf("hal_xdr_encode_int: work to failure\n");
- for (i = 1; i < 100; ++i) {
- if ((ret = hal_xdr_encode_int(&bufptr, limit, i)) != HAL_OK) {
- printf("%d: %s\n", i, hal_error_string(ret));
- break;
- }
- }
- hexdump(buf, ((uint8_t *)bufptr - buf));
-
- printf("\nhal_xdr_decode_int:\n");
- readptr = buf;
- while (readptr < bufptr) {
- if ((ret = hal_xdr_decode_int(&readptr, limit, &i)) != HAL_OK) {
- printf("%s\n", hal_error_string(ret));
- break;
- }
- printf("%u ", i);
- }
- printf("\n");
-
- printf("\nhal_xdr_encode_buffer: work to failure\n");
- memset(buf, 0, sizeof(buf));
- bufptr = buf;
- for (i = 1; i < 10; ++i) {
- if ((ret = hal_xdr_encode_buffer(&bufptr, limit, alphabet, i)) != HAL_OK) {
- printf("%d: %s\n", i, hal_error_string(ret));
- break;
- }
- }
- hexdump(buf, ((uint8_t *)bufptr - buf));
-
- printf("\nhal_xdr_decode_buffer:\n");
- readptr = buf;
- i = sizeof(readbuf);
- while (readptr < bufptr) {
- if ((ret = hal_xdr_decode_buffer(&readptr, limit, readbuf, &i)) != HAL_OK) {
- printf("%s\n", hal_error_string(ret));
- break;
- }
- printf("%u: ", i); for (int j = 0; j < i; ++j) putchar(readbuf[j]); putchar('\n');
- i = sizeof(readbuf);
- memset(readbuf, 0, sizeof(readbuf));
+ hal_error_t err;
+ size_t xdr_len;
+ const uint8_t *p;
+
+ /* read data pointer and length */
+ if ((err = hal_xdr_decode_variable_opaque_ptr(inbuf, limit, &p, &xdr_len)) == HAL_OK) {
+ /* user buffer overflow check */
+ if (*len < xdr_len)
+ return HAL_ERROR_XDR_BUFFER_OVERFLOW;
+ /* read the data */
+ memcpy(value, p, xdr_len);
+ *len = xdr_len;
}
- return 0;
+ return err;
}
-#endif