[dpdk-dev] [PATCH V16 3/4] eal/linux: uevent parse and process

[Jeff Guo]

In order to handle the uevent which have been detected from the kernel
side, add uevent parse and process function to translate the uevent into
device event, which user has subscribe to monitor.

Signed-off-by: Jeff Guo <jia.guo at intel.com>
---
1.move all linux specific together
---
 lib/librte_eal/linuxapp/eal/eal_dev.c | 214 +++++++++++++++++++++++++++++++++-
 1 file changed, 211 insertions(+), 3 deletions(-)

diff --git a/lib/librte_eal/linuxapp/eal/eal_dev.c b/lib/librte_eal/linuxapp/eal/eal_dev.c
index 5ab5830..90094c0 100644
--- a/lib/librte_eal/linuxapp/eal/eal_dev.c
+++ b/lib/librte_eal/linuxapp/eal/eal_dev.c
@@ -2,19 +2,227 @@
  * Copyright(c) 2018 Intel Corporation
  */
 
-#include <rte_log.h>
+#include <stdio.h>
+#include <string.h>
+#include <inttypes.h>
+#include <sys/queue.h>
+#include <sys/signalfd.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <linux/netlink.h>
+#include <sys/epoll.h>
+#include <unistd.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <fcntl.h>
+
+#include <rte_malloc.h>
+#include <rte_bus.h>
 #include <rte_dev.h>
+#include <rte_devargs.h>
+#include <rte_debug.h>
+#include <rte_log.h>
+#include <rte_interrupts.h>
+
+#include "eal_private.h"
+#include "eal_thread.h"
+
+static struct rte_intr_handle intr_handle = {.fd = -1 };
+static bool monitor_not_started = true;
+
+#define EAL_UEV_MSG_LEN 4096
+#define EAL_UEV_MSG_ELEM_LEN 128
+
+/* identify the system layer which event exposure from */
+enum eal_dev_event_subsystem {
+	EAL_DEV_EVENT_SUBSYSTEM_PCI, /* PCI bus device event */
+	EAL_DEV_EVENT_SUBSYSTEM_UIO, /* UIO driver device event */
+	EAL_DEV_EVENT_SUBSYSTEM_MAX
+};
+
+static int
+dev_uev_monitor_fd_new(void)
+{
+	int uevent_fd;
+
+	uevent_fd = socket(PF_NETLINK, SOCK_RAW | SOCK_CLOEXEC |
+			SOCK_NONBLOCK,
+			NETLINK_KOBJECT_UEVENT);
+	if (uevent_fd < 0) {
+		RTE_LOG(ERR, EAL, "create uevent fd failed\n");
+		return -1;
+	}
+	return uevent_fd;
+}
+
+static int
+dev_uev_monitor_create(int netlink_fd)
+{
+	struct sockaddr_nl addr;
+	int ret;
+	int size = 64 * 1024;
+	int nonblock = 1;
+
+	memset(&addr, 0, sizeof(addr));
+	addr.nl_family = AF_NETLINK;
+	addr.nl_pid = 0;
+	addr.nl_groups = 0xffffffff;
+
+	if (bind(netlink_fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
+		RTE_LOG(ERR, EAL, "bind failed\n");
+		goto err;
+	}
+
+	setsockopt(netlink_fd, SOL_SOCKET, SO_PASSCRED, &size, sizeof(size));
+
+	ret = ioctl(netlink_fd, FIONBIO, &nonblock);
+	if (ret != 0) {
+		RTE_LOG(ERR, EAL, "ioctl(FIONBIO) failed\n");
+		goto err;
+	}
+	return 0;
+err:
+	close(netlink_fd);
+	return -1;
+}
+
+static void
+dev_uev_parse(const char *buf, struct rte_dev_event *event, int length)
+{
+	char action[EAL_UEV_MSG_ELEM_LEN];
+	char subsystem[EAL_UEV_MSG_ELEM_LEN];
+	char dev_path[EAL_UEV_MSG_ELEM_LEN];
+	char pci_slot_name[EAL_UEV_MSG_ELEM_LEN];
+	int i = 0;
+
+	memset(action, 0, EAL_UEV_MSG_ELEM_LEN);
+	memset(subsystem, 0, EAL_UEV_MSG_ELEM_LEN);
+	memset(dev_path, 0, EAL_UEV_MSG_ELEM_LEN);
+	memset(pci_slot_name, 0, EAL_UEV_MSG_ELEM_LEN);
+
+	while (i < length) {
+		for (; i < length; i++) {
+			if (*buf)
+				break;
+			buf++;
+		}
+		if (!strncmp(buf, "ACTION=", 7)) {
+			buf += 7;
+			i += 7;
+			snprintf(action, sizeof(action), "%s", buf);
+		} else if (!strncmp(buf, "DEVPATH=", 8)) {
+			buf += 8;
+			i += 8;
+			snprintf(dev_path, sizeof(dev_path), "%s", buf);
+		} else if (!strncmp(buf, "SUBSYSTEM=", 10)) {
+			buf += 10;
+			i += 10;
+			snprintf(subsystem, sizeof(subsystem), "%s", buf);
+		} else if (!strncmp(buf, "PCI_SLOT_NAME=", 14)) {
+			buf += 14;
+			i += 14;
+			snprintf(pci_slot_name, sizeof(subsystem), "%s", buf);
+			event->devname = pci_slot_name;
+		}
+		for (; i < length; i++) {
+			if (*buf == '\0')
+				break;
+			buf++;
+		}
+	}
+
+	if (!strncmp(subsystem, "uio", 3))
+		event->subsystem = EAL_DEV_EVENT_SUBSYSTEM_UIO;
+	else if (!strncmp(subsystem, "pci", 3))
+		event->subsystem = EAL_DEV_EVENT_SUBSYSTEM_PCI;
+	if (!strncmp(action, "add", 3))
+		event->type = RTE_DEV_EVENT_ADD;
+	if (!strncmp(action, "remove", 6))
+		event->type = RTE_DEV_EVENT_REMOVE;
+}
+
+static int
+dev_uev_receive(int fd, struct rte_dev_event *uevent)
+{
+	int ret;
+	char buf[EAL_UEV_MSG_LEN];
+
+	memset(uevent, 0, sizeof(struct rte_dev_event));
+	memset(buf, 0, EAL_UEV_MSG_LEN);
+
+	ret = recv(fd, buf, EAL_UEV_MSG_LEN, MSG_DONTWAIT);
+	if (ret < 0) {
+		RTE_LOG(ERR, EAL,
+		"Socket read error(%d): %s\n",
+		errno, strerror(errno));
+		return -1;
+	} else if (ret == 0)
+		/* connection closed */
+		return -1;
+
+	dev_uev_parse(buf, uevent, EAL_UEV_MSG_LEN);
+
+	return 0;
+}
+
+static void
+dev_uev_process(__rte_unused void *param)
+{
+	struct rte_dev_event uevent;
+
+	if (dev_uev_receive(intr_handle.fd, &uevent))
+		return;
+
+	if (uevent.devname)
+		dev_callback_process(uevent.devname, uevent.type, NULL);
+}
 
 int __rte_experimental
 rte_dev_event_monitor_start(void)
 {
-	/* TODO: start uevent monitor for linux */
+	int ret;
+
+	if (!monitor_not_started)
+		return 0;
+
+	intr_handle.fd = dev_uev_monitor_fd_new();
+	intr_handle.type = RTE_INTR_HANDLE_DEV_EVENT;
+
+	ret = dev_uev_monitor_create(intr_handle.fd);
+
+	if (ret) {
+		RTE_LOG(ERR, EAL, "error create device event monitor\n");
+		return -1;
+	}
+
+	ret = rte_intr_callback_register(&intr_handle, dev_uev_process, NULL);
+
+	if (ret) {
+		RTE_LOG(ERR, EAL, "fail to register uevent callback\n");
+		return -1;
+	}
+
+	monitor_not_started = false;
+
 	return 0;
 }
 
 int __rte_experimental
 rte_dev_event_monitor_stop(void)
 {
-	/* TODO: stop uevent monitor for linux */
+	int ret;
+
+	if (monitor_not_started)
+		return 0;
+
+	ret = rte_intr_callback_unregister(&intr_handle, dev_uev_process, NULL);
+	if (ret) {
+		RTE_LOG(ERR, EAL, "fail to unregister uevent callback");
+		return ret;
+	}
+
+	close(intr_handle.fd);
+	intr_handle.fd = -1;
+	monitor_not_started = true;
 	return 0;
 }
-- 
2.7.4