Add helper to truncate the buffer to certain size which might be useful if some earlier part of the buffer can be reused multiple times without copying the whole buffer.
Signed-off-by: Ales Musil <[email protected]> --- v3: Rebase on top of current main. Change the semantics from "truncate by" to "truncate to". Use it in "ofpacts_parse()" function. v2: Rebase on top of current main. Add comment what the function does and test case. Fix the wrong move of data pointer. --- include/openvswitch/ofpbuf.h | 7 +++++++ lib/ofp-actions.c | 2 +- tests/test-ofpbuf.c | 10 ++++++++++ 3 files changed, 18 insertions(+), 1 deletion(-) diff --git a/include/openvswitch/ofpbuf.h b/include/openvswitch/ofpbuf.h index 1fc4a3a7f..0dfa51ecb 100644 --- a/include/openvswitch/ofpbuf.h +++ b/include/openvswitch/ofpbuf.h @@ -292,6 +292,13 @@ static inline bool ofpbuf_oversized(const struct ofpbuf *ofpacts) return (char *)ofpbuf_tail(ofpacts) - (char *)ofpacts->header > UINT16_MAX; } +/* Truncates the buffer to 'new_size' bytes from the tail end of 'b'. */ +static inline void ofpbuf_truncate(struct ofpbuf *b, size_t new_size) +{ + ovs_assert(b->size >= new_size); + b->size = new_size; +} + #ifdef __cplusplus } #endif diff --git a/lib/ofp-actions.c b/lib/ofp-actions.c index 8a05f7c9c..102abbc23 100644 --- a/lib/ofp-actions.c +++ b/lib/ofp-actions.c @@ -9674,7 +9674,7 @@ ofpacts_parse(char *str, const struct ofpact_parse_params *pp, uint32_t orig_size = pp->ofpacts->size; char *error = ofpacts_parse__(str, pp, allow_instructions, outer_action); if (error) { - pp->ofpacts->size = orig_size; + ofpbuf_truncate(pp->ofpacts, orig_size); } CONST_CAST(struct ofpact_parse_params *, pp)->depth--; return error; diff --git a/tests/test-ofpbuf.c b/tests/test-ofpbuf.c index 3d7fab90f..296d308a7 100644 --- a/tests/test-ofpbuf.c +++ b/tests/test-ofpbuf.c @@ -24,6 +24,7 @@ #define BUF_SIZE 100 #define HDR_OFS 10 #define MSG_OFS 50 +#define DATA_SIZE 16 static void test_ofpbuf_main(int argc OVS_UNUSED, char *argv[] OVS_UNUSED) @@ -59,6 +60,15 @@ test_ofpbuf_main(int argc OVS_UNUSED, char *argv[] OVS_UNUSED) ovs_assert(buf->header == (char *) buf->base + BUF_SIZE + HDR_OFS); ovs_assert(buf->msg == (char *) buf->base + BUF_SIZE + MSG_OFS); + size_t prev_size = buf->size; + ofpbuf_put_uninit(buf, DATA_SIZE); + ofpbuf_truncate(buf, prev_size); + /* Check that everything else is unchanged after truncate. */ + ovs_assert(!buf->size); + ovs_assert((char *) buf->base + BUF_SIZE == buf->data); + ovs_assert(buf->header == (char *) buf->base + BUF_SIZE + HDR_OFS); + ovs_assert(buf->msg == (char *) buf->base + BUF_SIZE + MSG_OFS); + ofpbuf_delete(buf); exit(exit_code); } -- 2.47.0 _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
