MINOR: ssl: reach a ckch_store from a sni_ctx

It was only possible to go down from the ckch_store to the sni_ctx but
not to go up from the sni_ctx to the ckch_store.

To allow that, 2 pointers were added:

- a ckch_inst pointer in the struct sni_ctx
- a ckckh_store pointer in the struct ckch_inst

include/types/ssl_sock.h

@@ -42,6 +42,7 @@ struct sni_ctx {
 	struct pkey_info kinfo;   /* pkey info */
 	struct ssl_bind_conf *conf; /* ssl "bind" conf for the certificate */
 	struct list by_ckch_inst; /* chained in ckch_inst's list of sni_ctx */
+	struct ckch_inst *ckch_inst; /* instance used to create this sni_ctx */
 	struct ebmb_node name;    /* node holding the servername value */
 };
 
@@ -126,6 +127,7 @@ struct ckch_store {
 struct ckch_inst {
 	struct bind_conf *bind_conf; /* pointer to the bind_conf that uses this ckch_inst */
 	struct ssl_bind_conf *ssl_conf; /* pointer to the ssl_conf which is used by every sni_ctx of this inst */
+	struct ckch_store *ckch_store; /* pointer to the store used to generate this inst */
 	int is_default;      /* This instance is used as the default ctx for this bind_conf */
 	struct list sni_ctx; /* list of sni_ctx using this ckch_inst */
 	struct list by_ckchs; /* chained in ckch_store's list of ckch_inst */

src/ssl_sock.c

@@ -2949,6 +2949,7 @@ static int ckch_inst_add_cert_sni(SSL_CTX *ctx, struct ckch_inst *ckch_inst,
 		sc->neg = neg;
 		sc->wild = wild;
 		sc->name.node.leaf_p = NULL;
+		sc->ckch_inst = ckch_inst;
 		LIST_ADDQ(&ckch_inst->sni_ctx, &sc->by_ckch_inst);
 	}
 	return order;
@@ -4186,6 +4187,7 @@ static int ckch_inst_new_load_multi_store(const char *path, struct ckch_store *c
 
 	ckch_inst->bind_conf = bind_conf;
 	ckch_inst->ssl_conf = ssl_conf;
+	ckch_inst->ckch_store = ckchs;
 end:
 
 	if (names)
@@ -4374,6 +4376,7 @@ static int ckch_inst_new_load_store(const char *path, struct ckch_store *ckchs,
 	/* everything succeed, the ckch instance can be used */
 	ckch_inst->bind_conf = bind_conf;
 	ckch_inst->ssl_conf = ssl_conf;
+	ckch_inst->ckch_store = ckchs;
 
 	*ckchi = ckch_inst;
 	return errcode;