A callback parameter to process replies will be useful for subsequent work
in this area. It implies the following:
- Replies may be much larger than requests. In fact their size cannot
really be known in advance. Using MNL_SOCKET_BUFFER_SIZE (at least 8192
bytes) is the recommended approach to make truncation less likely (look
for NLMSG_GOODSIZE in Linux).
- Multipart replies are made of several messages. A loop is needed to
process these.
- In case of truncated message (since one cannot really be sure),
its remaining parts must be flushed to prevent their reception by
subsequent queries.
- Using rte_get_tsc_cycles() instead of random() for message sequence
numbers is faster yet unlikely to pick the same number twice in a row.
- mlx5_nl_flow_init() can be simplified since the query message is never
written over (it was already the case actually).
Signed-off-by: Adrien Mazarguil <adrien.mazarg...@6wind.com>
---
drivers/net/mlx5/mlx5_nl_flow.c | 73 ++++++++++++++++++++++++------------
1 file changed, 48 insertions(+), 25 deletions(-)
diff --git a/drivers/net/mlx5/mlx5_nl_flow.c b/drivers/net/mlx5/mlx5_nl_flow.c
index 9ea2a1b55..e720728b7 100644
--- a/drivers/net/mlx5/mlx5_nl_flow.c
+++ b/drivers/net/mlx5/mlx5_nl_flow.c
@@ -22,6 +22,7 @@
#include <sys/socket.h>
#include <rte_byteorder.h>
+#include <rte_cycles.h>
#include <rte_errno.h>
#include <rte_ether.h>
#include <rte_flow.h>
@@ -1050,38 +1051,63 @@ mlx5_nl_flow_brand(void *buf, uint32_t handle)
}
/**
- * Send Netlink message with acknowledgment.
+ * Send Netlink message with acknowledgment and process reply.
*
* @param nl
* Libmnl socket to use.
* @param nlh
- * Message to send. This function always raises the NLM_F_ACK flag before
- * sending.
+ * Message to send. This function always raises the NLM_F_ACK flag and
+ * sets its sequence number before sending.
+ * @param cb
+ * Callback handler for received message.
+ * @param arg
+ * Data pointer for callback handler.
*
* @return
* 0 on success, a negative errno value otherwise and rte_errno is set.
*/
static int
-mlx5_nl_flow_nl_ack(struct mnl_socket *nl, struct nlmsghdr *nlh)
+mlx5_nl_flow_chat(struct mnl_socket *nl, struct nlmsghdr *nlh,
+ mnl_cb_t cb, void *arg)
{
alignas(struct nlmsghdr)
- uint8_t ans[mnl_nlmsg_size(sizeof(struct nlmsgerr)) +
- nlh->nlmsg_len - sizeof(*nlh)];
- uint32_t seq = random();
+ uint8_t ans[MNL_SOCKET_BUFFER_SIZE];
+ unsigned int portid = mnl_socket_get_portid(nl);
+ uint32_t seq = rte_get_tsc_cycles();
+ int err = 0;
int ret;
nlh->nlmsg_flags |= NLM_F_ACK;
nlh->nlmsg_seq = seq;
ret = mnl_socket_sendto(nl, nlh, nlh->nlmsg_len);
- if (ret != -1)
+ nlh = (void *)ans;
+ /*
+ * The following loop postpones non-fatal errors until multipart
+ * messages are complete.
+ */
+ while (ret > 0) {
ret = mnl_socket_recvfrom(nl, ans, sizeof(ans));
- if (ret != -1)
- ret = mnl_cb_run
- (ans, ret, seq, mnl_socket_get_portid(nl), NULL, NULL);
- if (!ret)
+ if (ret == -1) {
+ err = errno;
+ if (err != ENOSPC)
+ break;
+ ret = sizeof(*nlh);
+ }
+ if (!err) {
+ ret = mnl_cb_run(nlh, ret, seq, portid, cb, arg);
+ if (ret < 0)
+ err = -ret;
+ }
+ if (!(nlh->nlmsg_flags & NLM_F_MULTI) ||
+ nlh->nlmsg_type == NLMSG_DONE)
+ ret = -err;
+ else
+ ret = 1;
+ }
+ if (!err)
return 0;
- rte_errno = errno;
- return -rte_errno;
+ rte_errno = err;
+ return -err;
}
/**
@@ -1105,7 +1131,7 @@ mlx5_nl_flow_create(struct mnl_socket *nl, void *buf,
nlh->nlmsg_type = RTM_NEWTFILTER;
nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL;
- if (!mlx5_nl_flow_nl_ack(nl, nlh))
+ if (!mlx5_nl_flow_chat(nl, nlh, NULL, NULL))
return 0;
return rte_flow_error_set
(error, rte_errno, RTE_FLOW_ERROR_TYPE_UNSPECIFIED, NULL,
@@ -1133,7 +1159,7 @@ mlx5_nl_flow_destroy(struct mnl_socket *nl, void *buf,
nlh->nlmsg_type = RTM_DELTFILTER;
nlh->nlmsg_flags = NLM_F_REQUEST;
- if (!mlx5_nl_flow_nl_ack(nl, nlh))
+ if (!mlx5_nl_flow_chat(nl, nlh, NULL, NULL))
return 0;
return rte_flow_error_set
(error, errno, RTE_FLOW_ERROR_TYPE_UNSPECIFIED, NULL,
@@ -1171,23 +1197,20 @@ mlx5_nl_flow_ifindex_init(struct mnl_socket *nl,
unsigned int ifindex,
tcm->tcm_ifindex = ifindex;
tcm->tcm_handle = TC_H_MAKE(TC_H_INGRESS, 0);
tcm->tcm_parent = TC_H_INGRESS;
+ if (!mnl_attr_put_strz_check(nlh, sizeof(buf), TCA_KIND, "ingress"))
+ return rte_flow_error_set
+ (error, ENOBUFS, RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
+ NULL, "netlink: not enough space for message");
/* Ignore errors when qdisc is already absent. */
- if (mlx5_nl_flow_nl_ack(nl, nlh) &&
+ if (mlx5_nl_flow_chat(nl, nlh, NULL, NULL) &&
rte_errno != EINVAL && rte_errno != ENOENT)
return rte_flow_error_set
(error, rte_errno, RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
NULL, "netlink: failed to remove ingress qdisc");
/* Create fresh ingress qdisc. */
- nlh = mnl_nlmsg_put_header(buf);
nlh->nlmsg_type = RTM_NEWQDISC;
nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL;
- tcm = mnl_nlmsg_put_extra_header(nlh, sizeof(*tcm));
- tcm->tcm_family = AF_UNSPEC;
- tcm->tcm_ifindex = ifindex;
- tcm->tcm_handle = TC_H_MAKE(TC_H_INGRESS, 0);
- tcm->tcm_parent = TC_H_INGRESS;
- mnl_attr_put_strz_check(nlh, sizeof(buf), TCA_KIND, "ingress");
- if (mlx5_nl_flow_nl_ack(nl, nlh))
+ if (mlx5_nl_flow_chat(nl, nlh, NULL, NULL))
return rte_flow_error_set
(error, rte_errno, RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
NULL, "netlink: failed to create ingress qdisc");
--
2.11.0
