[dpdk-dev] [PATCH 1/2] net/tap: update netlink error code management
Pascal Mazon
pascal.mazon at 6wind.com
Wed Mar 29 11:44:08 CEST 2017
Some errors received from the kernel are acceptable, such as a -ENOENT
for a rule deletion (the rule was already no longer existing in the
kernel). Make sure we consider return codes properly. For that,
nl_recv() has been simplified.
qdisc_exists() function is no longer needed as we can check whether the
kernel returned -EEXIST when requiring the qdisc creation. It's simpler
and faster.
Add a few messages for clarity when a netlink error occurs.
Signed-off-by: Pascal Mazon <pascal.mazon at 6wind.com>
---
drivers/net/tap/tap_flow.c | 22 ++++++++-
drivers/net/tap/tap_netlink.c | 73 +++++++++++++---------------
drivers/net/tap/tap_tcmsgs.c | 107 ++++++++++--------------------------------
drivers/net/tap/tap_tcmsgs.h | 2 -
4 files changed, 80 insertions(+), 124 deletions(-)
diff --git a/drivers/net/tap/tap_flow.c b/drivers/net/tap/tap_flow.c
index 7f1693d40468..514e3fae5c38 100644
--- a/drivers/net/tap/tap_flow.c
+++ b/drivers/net/tap/tap_flow.c
@@ -31,6 +31,8 @@
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
+#include <errno.h>
+#include <string.h>
#include <sys/queue.h>
#include <rte_byteorder.h>
@@ -1165,6 +1167,9 @@ tap_flow_create(struct rte_eth_dev *dev,
}
err = nl_recv_ack(pmd->nlsk_fd);
if (err < 0) {
+ RTE_LOG(ERR, PMD,
+ "Kernel refused TC filter rule creation (%d): %s\n",
+ errno, strerror(errno));
rte_flow_error_set(error, EEXIST, RTE_FLOW_ERROR_TYPE_HANDLE,
NULL, "overlapping rules");
goto fail;
@@ -1206,6 +1211,9 @@ tap_flow_create(struct rte_eth_dev *dev,
}
err = nl_recv_ack(pmd->nlsk_fd);
if (err < 0) {
+ RTE_LOG(ERR, PMD,
+ "Kernel refused TC filter rule creation (%d): %s\n",
+ errno, strerror(errno));
rte_flow_error_set(
error, ENOMEM, RTE_FLOW_ERROR_TYPE_HANDLE,
NULL, "overlapping rules");
@@ -1253,7 +1261,13 @@ tap_flow_destroy_pmd(struct pmd_internals *pmd,
goto end;
}
ret = nl_recv_ack(pmd->nlsk_fd);
+ /* If errno is ENOENT, the rule is already no longer in the kernel. */
+ if (ret < 0 && errno == ENOENT)
+ ret = 0;
if (ret < 0) {
+ RTE_LOG(ERR, PMD,
+ "Kernel refused TC filter rule deletion (%d): %s\n",
+ errno, strerror(errno));
rte_flow_error_set(
error, ENOTSUP, RTE_FLOW_ERROR_TYPE_HANDLE, NULL,
"couldn't receive kernel ack to our request");
@@ -1271,7 +1285,12 @@ tap_flow_destroy_pmd(struct pmd_internals *pmd,
goto end;
}
ret = nl_recv_ack(pmd->nlsk_fd);
+ if (ret < 0 && errno == ENOENT)
+ ret = 0;
if (ret < 0) {
+ RTE_LOG(ERR, PMD,
+ "Kernel refused TC filter rule deletion (%d): %s\n",
+ errno, strerror(errno));
rte_flow_error_set(
error, ENOMEM, RTE_FLOW_ERROR_TYPE_HANDLE,
NULL, "Failure trying to receive nl ack");
@@ -1386,7 +1405,8 @@ int tap_flow_implicit_create(struct pmd_internals *pmd,
err = nl_recv_ack(pmd->nlsk_fd);
if (err < 0) {
RTE_LOG(ERR, PMD,
- "Kernel refused TC filter rule creation");
+ "Kernel refused TC filter rule creation (%d): %s\n",
+ errno, strerror(errno));
goto fail;
}
LIST_INSERT_HEAD(&pmd->implicit_flows, remote_flow, next);
diff --git a/drivers/net/tap/tap_netlink.c b/drivers/net/tap/tap_netlink.c
index 6de896ab17b6..ee92e2e7ed13 100644
--- a/drivers/net/tap/tap_netlink.c
+++ b/drivers/net/tap/tap_netlink.c
@@ -159,7 +159,7 @@ nl_send(int nlsk_fd, struct nlmsghdr *nh)
* The netlink socket file descriptor used for communication.
*
* @return
- * 0 on success, -1 otherwise.
+ * 0 on success, -1 otherwise with errno set.
*/
int
nl_recv_ack(int nlsk_fd)
@@ -179,14 +179,13 @@ nl_recv_ack(int nlsk_fd)
* Custom arguments for the callback.
*
* @return
- * 0 on success, -1 otherwise.
+ * 0 on success, -1 otherwise with errno set.
*/
int
nl_recv(int nlsk_fd, int (*cb)(struct nlmsghdr *, void *arg), void *arg)
{
/* man 7 netlink EXAMPLE */
struct sockaddr_nl sa;
- struct nlmsghdr *nh;
char buf[BUF_SIZE];
struct iovec iov = {
.iov_base = buf,
@@ -196,49 +195,43 @@ nl_recv(int nlsk_fd, int (*cb)(struct nlmsghdr *, void *arg), void *arg)
.msg_name = &sa,
.msg_namelen = sizeof(sa),
.msg_iov = &iov,
+ /* One message at a time */
.msg_iovlen = 1,
};
- int recv_bytes = 0, done = 0, multipart = 0, error = 0;
+ int multipart = 0;
+ int ret = 0;
-read:
- recv_bytes = recvmsg(nlsk_fd, &msg, 0);
- if (recv_bytes < 0)
- return -1;
- for (nh = (struct nlmsghdr *)buf;
- NLMSG_OK(nh, (unsigned int)recv_bytes);
- nh = NLMSG_NEXT(nh, recv_bytes)) {
- /*
- * Multi-part messages and their following DONE message have the
- * NLM_F_MULTI flag set. Make note, in order to read the DONE
- * message afterwards.
- */
- if (nh->nlmsg_flags & NLM_F_MULTI)
- multipart = 1;
- if (nh->nlmsg_type == NLMSG_ERROR) {
- struct nlmsgerr *err_data = NLMSG_DATA(nh);
+ do {
+ struct nlmsghdr *nh;
+ int recv_bytes = 0;
+
+ recv_bytes = recvmsg(nlsk_fd, &msg, 0);
+ if (recv_bytes < 0)
+ return -1;
+ for (nh = (struct nlmsghdr *)buf;
+ NLMSG_OK(nh, (unsigned int)recv_bytes);
+ nh = NLMSG_NEXT(nh, recv_bytes)) {
+ if (nh->nlmsg_type == NLMSG_ERROR) {
+ struct nlmsgerr *err_data = NLMSG_DATA(nh);
- if (err_data->error == 0)
- RTE_LOG(DEBUG, PMD, "%s() ack message recvd\n",
- __func__);
- else {
- RTE_LOG(DEBUG, PMD,
- "%s() error message recvd\n", __func__);
- error = 1;
+ if (err_data->error < 0) {
+ errno = -err_data->error;
+ return -1;
+ }
+ /* Ack message. */
+ return 0;
}
+ /* Multi-part msgs and their trailing DONE message. */
+ if (nh->nlmsg_flags & NLM_F_MULTI) {
+ if (nh->nlmsg_type == NLMSG_DONE)
+ return 0;
+ multipart = 1;
+ }
+ if (cb)
+ ret = cb(nh, arg);
}
- /* The end of multipart message. */
- if (nh->nlmsg_type == NLMSG_DONE)
- /* No need to call the callback for a DONE message. */
- done = 1;
- else if (cb)
- if (cb(nh, arg) < 0)
- error = 1;
- }
- if (multipart && !done)
- goto read;
- if (error)
- return -1;
- return 0;
+ } while (multipart);
+ return ret;
}
/**
diff --git a/drivers/net/tap/tap_tcmsgs.c b/drivers/net/tap/tap_tcmsgs.c
index af1c9aec0d22..d74ac805b184 100644
--- a/drivers/net/tap/tap_tcmsgs.c
+++ b/drivers/net/tap/tap_tcmsgs.c
@@ -94,7 +94,7 @@ tc_init_msg(struct nlmsg *msg, uint16_t ifindex, uint16_t type, uint16_t flags)
* Additional info to identify the QDISC (handle and parent).
*
* @return
- * 0 on success, -1 otherwise.
+ * 0 on success, -1 otherwise with errno set.
*/
static int
qdisc_del(int nlsk_fd, uint16_t ifindex, struct qdisc *qinfo)
@@ -117,12 +117,16 @@ qdisc_del(int nlsk_fd, uint16_t ifindex, struct qdisc *qinfo)
fd = nlsk_fd;
}
if (nl_send(fd, &msg.nh) < 0)
- return -1;
+ goto error;
if (nl_recv_ack(fd) < 0)
- return -1;
+ goto error;
if (!nlsk_fd)
return nl_final(fd);
return 0;
+error:
+ if (!nlsk_fd)
+ nl_final(fd);
+ return -1;
}
/**
@@ -134,7 +138,7 @@ qdisc_del(int nlsk_fd, uint16_t ifindex, struct qdisc *qinfo)
* The netdevice ifindex where to add the multiqueue QDISC.
*
* @return
- * -1 if the qdisc cannot be added, and 0 otherwise.
+ * 0 on success, -1 otherwise with errno set.
*/
int
qdisc_add_multiq(int nlsk_fd, uint16_t ifindex)
@@ -164,7 +168,7 @@ qdisc_add_multiq(int nlsk_fd, uint16_t ifindex)
* The netdevice ifindex where the QDISC will be added.
*
* @return
- * -1 if the qdisc cannot be added, and 0 otherwise.
+ * 0 on success, -1 otherwise with errno set.
*/
int
qdisc_add_ingress(int nlsk_fd, uint16_t ifindex)
@@ -184,34 +188,6 @@ qdisc_add_ingress(int nlsk_fd, uint16_t ifindex)
}
/**
- * Callback function to check for QDISC existence.
- * If the QDISC is found to exist, increment "exists" in the custom arg.
- *
- * @param[in] nh
- * The netlink message to parse, received from the kernel.
- * @param[in, out] arg
- * Custom arguments for the callback.
- *
- * @return
- * 0.
- */
-static int
-qdisc_exist_cb(struct nlmsghdr *nh, void *arg)
-{
- struct list_args *args = (struct list_args *)arg;
- struct qdisc_custom_arg *custom = args->custom_arg;
- struct tcmsg *t = NLMSG_DATA(nh);
-
- /* filter by request iface */
- if (args->ifindex != (unsigned int)t->tcm_ifindex)
- return 0;
- if (t->tcm_handle != custom->handle || t->tcm_parent != custom->parent)
- return 0;
- custom->exists++;
- return 0;
-}
-
-/**
* Callback function to delete a QDISC.
*
* @param[in] nh
@@ -220,7 +196,7 @@ qdisc_exist_cb(struct nlmsghdr *nh, void *arg)
* Custom arguments for the callback.
*
* @return
- * 0.
+ * 0 on success, -1 otherwise with errno set.
*/
static int
qdisc_del_cb(struct nlmsghdr *nh, void *arg)
@@ -256,10 +232,7 @@ qdisc_del_cb(struct nlmsghdr *nh, void *arg)
* The arguments to provide the callback function with.
*
* @return
- * -1 if either sending the netlink message failed, or if receiving the answer
- * failed, or finally if the callback returned a negative value for that
- * answer.
- * 0 is returned otherwise.
+ * 0 on success, -1 otherwise with errno set.
*/
static int
qdisc_iterate(int nlsk_fd, uint16_t ifindex,
@@ -281,36 +254,6 @@ qdisc_iterate(int nlsk_fd, uint16_t ifindex,
}
/**
- * Check whether a given QDISC already exists for the netdevice.
- *
- * @param[in] nlsk_fd
- * The netlink socket file descriptor used for communication.
- * @param[in] ifindex
- * The netdevice ifindex to check QDISC existence for.
- * @param[in] callback
- * The function to call for each QDISC.
- * @param[in, out] arg
- * The arguments to provide the callback function with.
- *
- * @return
- * 1 if the qdisc exists, 0 otherwise.
- */
-int
-qdisc_exists(int nlsk_fd, uint16_t ifindex, uint32_t handle, uint32_t parent)
-{
- struct qdisc_custom_arg arg = {
- .handle = handle,
- .parent = parent,
- .exists = 0,
- };
-
- qdisc_iterate(nlsk_fd, ifindex, qdisc_exist_cb, &arg);
- if (arg.exists)
- return 1;
- return 0;
-}
-
-/**
* Delete all QDISCs for a given netdevice.
*
* @param[in] nlsk_fd
@@ -319,7 +262,7 @@ qdisc_exists(int nlsk_fd, uint16_t ifindex, uint32_t handle, uint32_t parent)
* The netdevice ifindex where to find QDISCs.
*
* @return
- * -1 if the lookup failed, 0 otherwise.
+ * 0 on success, -1 otherwise with errno set.
*/
int
qdisc_flush(int nlsk_fd, uint16_t ifindex)
@@ -342,12 +285,13 @@ qdisc_flush(int nlsk_fd, uint16_t ifindex)
int
qdisc_create_multiq(int nlsk_fd, uint16_t ifindex)
{
- if (!qdisc_exists(nlsk_fd, ifindex,
- TC_H_MAKE(MULTIQ_MAJOR_HANDLE, 0), TC_H_ROOT)) {
- if (qdisc_add_multiq(nlsk_fd, ifindex) < 0) {
- RTE_LOG(ERR, PMD, "Could not add multiq qdisc\n");
- return -1;
- }
+ int err = 0;
+
+ err = qdisc_add_multiq(nlsk_fd, ifindex);
+ if (err < 0 && errno != -EEXIST) {
+ RTE_LOG(ERR, PMD, "Could not add multiq qdisc (%d): %s\n",
+ errno, strerror(errno));
+ return -1;
}
return 0;
}
@@ -367,12 +311,13 @@ qdisc_create_multiq(int nlsk_fd, uint16_t ifindex)
int
qdisc_create_ingress(int nlsk_fd, uint16_t ifindex)
{
- if (!qdisc_exists(nlsk_fd, ifindex,
- TC_H_MAKE(TC_H_INGRESS, 0), TC_H_INGRESS)) {
- if (qdisc_add_ingress(nlsk_fd, ifindex) < 0) {
- RTE_LOG(ERR, PMD, "Could not add ingress qdisc\n");
- return -1;
- }
+ int err = 0;
+
+ err = qdisc_add_ingress(nlsk_fd, ifindex);
+ if (err < 0 && errno != -EEXIST) {
+ RTE_LOG(ERR, PMD, "Could not add ingress qdisc (%d): %s\n",
+ errno, strerror(errno));
+ return -1;
}
return 0;
}
diff --git a/drivers/net/tap/tap_tcmsgs.h b/drivers/net/tap/tap_tcmsgs.h
index a571a56d6964..789595771d63 100644
--- a/drivers/net/tap/tap_tcmsgs.h
+++ b/drivers/net/tap/tap_tcmsgs.h
@@ -50,8 +50,6 @@
void tc_init_msg(struct nlmsg *msg, uint16_t ifindex, uint16_t type,
uint16_t flags);
-int qdisc_exists(int nlsk_fd, uint16_t ifindex, uint32_t handle,
- uint32_t parent);
int qdisc_list(int nlsk_fd, uint16_t ifindex);
int qdisc_flush(int nlsk_fd, uint16_t ifindex);
int qdisc_create_ingress(int nlsk_fd, uint16_t ifindex);
--
2.12.0.306.g4a9b9b3
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