> Removed VLA for compatibility with MSVC (which does not support VLAs).
> Used alloca when a constant fixed length that can be used instead is
> not known.
>
...
> Signed-off-by: Andre Muezerie <andre...@linux.microsoft.com>
> ---
...
> diff --git a/lib/ipsec/esp_inb.c b/lib/ipsec/esp_inb.c
> index f159bf7460..305ac48dc5 100644
> --- a/lib/ipsec/esp_inb.c
> +++ b/lib/ipsec/esp_inb.c
> @@ -370,8 +370,9 @@ esp_inb_pkt_prepare(const struct rte_ipsec_session *ss,
> struct rte_mbuf *mb[],
> struct rte_cryptodev_sym_session *cs;
> struct replay_sqn *rsn;
> union sym_op_data icv;
> - uint32_t dr[num];
> + uint32_t *dr;
I understand the intention, but obviously as the lib maintainer, I am no
very happy with mechanic replacement of VLAs with alloca() calls.
Again, while it helps to make MSVC happy, it doesn't really solve a potential
problem
with using VLAs here - I we can end-up with stack overflowed if someone will
call
one of these functions with input arrays of huge size.
It would be much better to re-work the internal functions to work over
fixed-size array
an then call them in a loop.
The main issue here is that by API convention we need to re-arrange input array
by
moving bad (not processed) mbuf after the good ones.
But even with that splitting processing into multiple iterations over small
chunks
might help I think.
> + dr = alloca(sizeof(uint32_t) * num);
> sa = ss->sa;
> cs = ss->crypto.ses;
> rsn = rsn_acquire(sa);
> @@ -576,12 +577,16 @@ tun_process(struct rte_ipsec_sa *sa, struct rte_mbuf
> *mb[],
> uint32_t sqn[], uint32_t dr[], uint16_t num, uint8_t sqh_len)
> {
> uint32_t adj, i, k, tl, bytes;
> - uint32_t hl[num], to[num];
> - struct rte_esp_tail espt[num];
> - struct rte_mbuf *ml[num];
> + uint32_t *hl, *to;
> + struct rte_esp_tail *espt;
> + struct rte_mbuf **ml;
> const void *outh;
> void *inh;
>
> + hl = alloca(sizeof(uint32_t) * num);
> + to = alloca(sizeof(uint32_t) * num);
> + espt = alloca(sizeof(struct rte_esp_tail) * num);
> + ml = alloca(sizeof(struct rte_mbuf *) * num);
> /*
> * remove icv, esp trailer and high-order
> * 32 bits of esn from packet length
