[PATCH v5 10/10] common/dpaxx: replace zero length array

[Stephen Hemminger]

The zero length ip_header is used as an overlay to the
encap IP header. Since the code is already assuming the layout
of the structure, replace the array with direct access.

Signed-off-by: Stephen Hemminger <step...@networkplumber.org>
Acked-by: Hemant Agrawal <hemant.agra...@nxp.com>
---
 drivers/common/dpaax/caamflib/desc/ipsec.h | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/common/dpaax/caamflib/desc/ipsec.h 
b/drivers/common/dpaax/caamflib/desc/ipsec.h
index 95fc3ea5ba3b..d1411cc6aab4 100644
--- a/drivers/common/dpaax/caamflib/desc/ipsec.h
+++ b/drivers/common/dpaax/caamflib/desc/ipsec.h
@@ -334,9 +334,7 @@ struct ipsec_encap_gcm {
  * @seq_num: IPsec sequence number
  * @spi: IPsec SPI (Security Parameters Index)
  * @ip_hdr_len: optional IP Header length (in bytes)
- *  reserved - 16b
- *  Opt. IP Hdr Len - 16b
- * @ip_hdr: optional IP Header content (only for IPsec legacy mode)
+ *  Ip header must follow directly after ipsec_encap_pdb
  */
 struct ipsec_encap_pdb {
        uint32_t options;
@@ -350,7 +348,6 @@ struct ipsec_encap_pdb {
        };
        uint32_t spi;
        uint32_t ip_hdr_len;
-       uint8_t ip_hdr[0];
 };
 
 static inline unsigned int
@@ -776,7 +773,12 @@ cnstr_shdsc_ipsec_encap(uint32_t *descbuf, bool ps, bool 
swap,
                PROGRAM_SET_36BIT_ADDR(p);
        phdr = SHR_HDR(p, share, hdr, 0);
        __rta_copy_ipsec_encap_pdb(p, pdb, cipherdata->algtype);
-       COPY_DATA(p, pdb->ip_hdr, pdb->ip_hdr_len);
+
+       /* ip header if any follows the encap_pdb */
+       if (pdb->ip_hdr_len > 0) {
+               void *ip_hdr = pdb + 1;
+               COPY_DATA(p, ip_hdr, pdb->ip_hdr_len);
+       }
        SET_LABEL(p, hdr);
        pkeyjmp = JUMP(p, keyjmp, LOCAL_JUMP, ALL_TRUE, BOTH|SHRD);
        if (authdata->keylen)
@@ -913,7 +915,13 @@ cnstr_shdsc_ipsec_encap_des_aes_xcbc(uint32_t *descbuf,
        PROGRAM_CNTXT_INIT(p, descbuf, 0);
        phdr = SHR_HDR(p, share, hdr, 0);
        __rta_copy_ipsec_encap_pdb(p, pdb, cipherdata->algtype);
-       COPY_DATA(p, pdb->ip_hdr, pdb->ip_hdr_len);
+
+       /* ip header if any follows the encap_pdb */
+       if (pdb->ip_hdr_len > 0) {
+               void *ip_hdr = pdb + 1;
+               COPY_DATA(p, ip_hdr, pdb->ip_hdr_len);
+       }
+
        SET_LABEL(p, hdr);
        pkeyjump = JUMP(p, keyjump, LOCAL_JUMP, ALL_TRUE, SHRD | SELF);
        /*
-- 
2.42.0