The tx rekey operation creates a new psp_assoc with the same rx state, but with new tx state. The new psp_assoc will reference the current assocs 'prev' assoc as its own. The assoc referenced by 'sk->psp_assoc' will have its reference dropped and be freed.
Signed-off-by: Daniel Zahka <[email protected]> --- net/psp/psp_sock.c | 51 +++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 45 insertions(+), 6 deletions(-) diff --git a/net/psp/psp_sock.c b/net/psp/psp_sock.c index 9b0ecce8350f..f429b8b2d8f2 100644 --- a/net/psp/psp_sock.c +++ b/net/psp/psp_sock.c @@ -215,6 +215,47 @@ psp_pas_set_tx_key(struct psp_dev *psd, struct psp_assoc *pas, return rc; } +static int +psp_sock_tx_rekey(struct sock *sk, struct psp_dev *psd, struct psp_assoc *pas, + struct psp_key_parsed *key, struct netlink_ext_ack *extack) +{ + struct psp_assoc *new; + size_t pas_sz; + int err; + + pas_sz = struct_size(new, drv_data, psd->caps->assoc_drv_spc); + new = kzalloc(pas_sz, GFP_KERNEL_ACCOUNT); + if (!new) + return -ENOMEM; + + /* don't increase refcounts until we know we won't fail */ + new->psd = pas->psd; + new->dev_id = pas->dev_id; + new->generation = pas->generation; + new->version = pas->version; + new->peer_tx = pas->peer_tx; + new->upgrade_seq = pas->upgrade_seq; + new->prev = pas->prev; + refcount_set(&new->refcnt, 1); + memcpy(&new->rx, &pas->rx, sizeof(new->rx)); + + err = psp_pas_set_tx_key(psd, new, key, extack); + if (err) { + kfree(new); + return err; + } + + psp_dev_get(new->psd); + if (new->prev) + refcount_inc(&new->prev->refcnt); + list_add_tail(&new->assocs_list, &psd->active_assocs); + + rcu_assign_pointer(sk->psp_assoc, new); + psp_assoc_put(pas); + + return 0; +} + static int psp_sock_set_tx_key(struct sock *sk, struct psp_dev *psd, struct psp_assoc *pas, struct psp_key_parsed *key, struct netlink_ext_ack *extack) @@ -269,13 +310,11 @@ int psp_sock_assoc_set_tx(struct sock *sk, struct psp_dev *psd, err = -EINVAL; goto exit_unlock; } - if (pas->tx.spi) { - NL_SET_ERR_MSG(extack, "Tx key already set"); - err = -EBUSY; - goto exit_unlock; - } + if (pas->tx.spi) + err = psp_sock_tx_rekey(sk, psd, pas, key, extack); + else + err = psp_sock_set_tx_key(sk, psd, pas, key, extack); - err = psp_sock_set_tx_key(sk, psd, pas, key, extack); exit_unlock: release_sock(sk); return err; -- 2.47.3
