Make dbuff usage more idiomatic (#3940)

diff --git a/src/protocols/dhcpv6/encode.c b/src/protocols/dhcpv6/encode.c
index 1fa5dc90f3d0e86d90e15fea26347ea006a27637..8a7639a73dba5cbe4e8b016bf092d7aa4cc47c34 100644 (file)
--- a/src/protocols/dhcpv6/encode.c
+++ b/src/protocols/dhcpv6/encode.c
@@ -63,21 +63,19 @@ static ssize_t encode_tlv(fr_dbuff_t *dbuff,
  *   |          option-code          |           option-len          |
  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  *
- * @param[out] dbuff           Where to write the 4 byte option header.
+ * @param[out] m               Where to write the 4 byte option header.
  * @param[in] option           The option number (host byte order).
  * @param[in] data_len         The length of the option (host byte order).
  * @return
  *     - <0    How much data would have been required as a negative value.
  *     - 4     The length of data written.
  */
-static inline ssize_t encode_option_hdr(fr_dbuff_t *dbuff, uint16_t option, size_t data_len)
+static inline ssize_t encode_option_hdr(fr_dbuff_marker_t *m, uint16_t option, size_t data_len)
 {
-       fr_dbuff_t      work_dbuff = FR_DBUFF_NO_ADVANCE(dbuff);
+       FR_DBUFF_IN_RETURN(m, option);
+       FR_DBUFF_IN_RETURN(m, (uint16_t) data_len);
 
-       FR_DBUFF_IN_RETURN(&work_dbuff, option);
-       FR_DBUFF_IN_RETURN(&work_dbuff, (uint16_t) data_len);
-
-       return fr_dbuff_set(dbuff, &work_dbuff);
+       return sizeof(option) + sizeof(uint16_t);
 }
 
 
@@ -156,9 +154,10 @@ static ssize_t encode_value(fr_dbuff_t *dbuff,
                if (!da->flags.extra &&
                    ((da->flags.subtype == FLAG_ENCODE_DNS_LABEL) ||
                     (da->flags.subtype == FLAG_ENCODE_PARTIAL_DNS_LABEL))) {
-                       fr_dbuff_marker_t       p;
+                       fr_dbuff_marker_t       last_byte, src;
 
-                       fr_dbuff_marker(&p, &work_dbuff);
+                       fr_dbuff_marker(&last_byte, &work_dbuff);
+                       fr_dbuff_marker(&src, &work_dbuff);
                        slen = fr_dns_label_from_value_box_dbuff(&work_dbuff, false, &vp->data);
                        if (slen < 0) return slen;
 
@@ -168,10 +167,13 @@ static ssize_t encode_value(fr_dbuff_t *dbuff,
                         *      partial name, and we omit the trailing
                         *      zero.
                         */
-                       if ((da->flags.subtype == FLAG_ENCODE_PARTIAL_DNS_LABEL) &&
-                           (*(fr_dbuff_current(&p) + fr_dbuff_current(&p)[0] + 1) == 0)) {
-                               fr_dbuff_set_to_start(&work_dbuff);
-                               fr_dbuff_advance(&work_dbuff, (size_t)slen - 1);
+                       if ((da->flags.subtype == FLAG_ENCODE_PARTIAL_DNS_LABEL) && slen > 0) {
+                               uint8_t c = 0;
+
+                               fr_dbuff_advance(&last_byte, (size_t)(slen - 1));
+                               fr_dbuff_set(&src, &last_byte);
+                               fr_dbuff_out(&c, &src);
+                               if (!c) fr_dbuff_set(&work_dbuff, &last_byte);
                        }
                        break;
                }
@@ -512,16 +514,18 @@ static ssize_t encode_rfc_hdr(fr_dbuff_t *dbuff,
                              fr_dcursor_t *cursor, void *encoder_ctx)
 {
        fr_dbuff_t              work_dbuff = FR_DBUFF_NO_ADVANCE(dbuff);
-       fr_dbuff_t              hdr_dbuff = FR_DBUFF_NO_ADVANCE(dbuff);
+       fr_dbuff_marker_t       hdr;
        fr_dict_attr_t const    *da = da_stack->da[depth];
        ssize_t                 len;
 
        FR_PROTO_STACK_PRINT(da_stack, depth);
+       fr_dbuff_marker(&hdr, &work_dbuff);
 
        /*
         *      Make space for the header...
         */
-       FR_DBUFF_ADVANCE_RETURN(&work_dbuff, DHCPV6_OPT_HDR_LEN);
+       FR_DBUFF_EXTEND_LOWAT_OR_RETURN(&work_dbuff, DHCPV6_OPT_HDR_LEN);
+       fr_dbuff_advance(&work_dbuff, DHCPV6_OPT_HDR_LEN);
 
        /*
         *      Write out the option's value
@@ -536,7 +540,7 @@ static ssize_t encode_rfc_hdr(fr_dbuff_t *dbuff,
        /*
         *      Write out the option number and length (before the value we just wrote)
         */
-       encode_option_hdr(&hdr_dbuff, (uint16_t)da->attr, (uint16_t) (fr_dbuff_used(&work_dbuff) - DHCPV6_OPT_HDR_LEN));
+       (void) encode_option_hdr(&hdr, (uint16_t)da->attr, (uint16_t) (fr_dbuff_used(&work_dbuff) - DHCPV6_OPT_HDR_LEN));
 
        FR_PROTO_HEX_DUMP(fr_dbuff_start(&work_dbuff), fr_dbuff_used(&work_dbuff), "Done RFC header");
 
@@ -548,10 +552,11 @@ static ssize_t encode_tlv_hdr(fr_dbuff_t *dbuff,
                              fr_dcursor_t *cursor, void *encoder_ctx)
 {
        fr_dbuff_t              work_dbuff = FR_DBUFF_NO_ADVANCE(dbuff);
-       fr_dbuff_t              hdr_dbuff = FR_DBUFF_NO_ADVANCE(dbuff);
+       fr_dbuff_marker_t       hdr;
        fr_dict_attr_t const    *da = da_stack->da[depth];
        ssize_t                 len;
 
+       fr_dbuff_marker(&hdr, &work_dbuff);
        VP_VERIFY(fr_dcursor_current(cursor));
        FR_PROTO_STACK_PRINT(da_stack, depth);
 
@@ -578,7 +583,7 @@ static ssize_t encode_tlv_hdr(fr_dbuff_t *dbuff,
         *   |          option-code          |           option-len          |
         *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
         */
-       encode_option_hdr(&hdr_dbuff, (uint16_t)da->attr, (uint16_t) (fr_dbuff_used(&work_dbuff) - DHCPV6_OPT_HDR_LEN));
+       (void) encode_option_hdr(&hdr, (uint16_t)da->attr, (uint16_t) (fr_dbuff_used(&work_dbuff) - DHCPV6_OPT_HDR_LEN));
 
        FR_PROTO_HEX_DUMP(fr_dbuff_start(&work_dbuff), fr_dbuff_used(&work_dbuff), "Done TLV header");
 
@@ -603,11 +608,12 @@ static ssize_t encode_vsio_hdr(fr_dbuff_t *dbuff,
                               fr_dcursor_t *cursor, void *encoder_ctx)
 {
        fr_dbuff_t              work_dbuff = FR_DBUFF_NO_ADVANCE(dbuff);
-       fr_dbuff_t              hdr_dbuff = FR_DBUFF_NO_ADVANCE(dbuff);
+       fr_dbuff_marker_t       hdr;
        fr_dict_attr_t const    *da = da_stack->da[depth];
        fr_dict_attr_t const    *dv;
        ssize_t                 len;
 
+       fr_dbuff_marker(&hdr, &work_dbuff);
        FR_PROTO_STACK_PRINT(da_stack, depth);
 
        /*
@@ -631,7 +637,8 @@ static ssize_t encode_vsio_hdr(fr_dbuff_t *dbuff,
                return PAIR_ENCODE_FATAL_ERROR;
        }
 
-       FR_DBUFF_ADVANCE_RETURN(&work_dbuff, DHCPV6_OPT_HDR_LEN);
+       FR_DBUFF_EXTEND_LOWAT_OR_RETURN(&work_dbuff, DHCPV6_OPT_HDR_LEN);
+       fr_dbuff_advance(&work_dbuff, DHCPV6_OPT_HDR_LEN);
        FR_DBUFF_IN_RETURN(&work_dbuff, dv->attr);
 
        /*
@@ -667,7 +674,7 @@ static ssize_t encode_vsio_hdr(fr_dbuff_t *dbuff,
        }
        if (len < 0) return len;
 
-       encode_option_hdr(&hdr_dbuff, da->attr, fr_dbuff_used(&work_dbuff) - DHCPV6_OPT_HDR_LEN);
+       (void) encode_option_hdr(&hdr, da->attr, fr_dbuff_used(&work_dbuff) - DHCPV6_OPT_HDR_LEN);
 
        FR_PROTO_HEX_DUMP(fr_dbuff_start(&work_dbuff), fr_dbuff_used(&work_dbuff), "Done VSIO header");