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udevd: listen for netlink events 

After the first valid netlink-event all event with a serial number
received on the udevsend socket will be ignored.

Signed-off-by: Kay Sievers <kay.sievers@suse.de>
This commit is contained in:
Kay Sievers 2005-06-05 04:38:10 +02:00
parent 5e65ab9a19
commit 88f4b6485e
2 changed files with 165 additions and 41 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
udev.c
View File

@ -54,8 +54,10 @@ void log_message(int priority, const char *format, ...)
}
#endif
/* decide if we should manage the whole hotplug event
* for now look if the kernel calls udevsend instead of /sbin/hotplug
/* Decide if we should manage the whole uevent, including multiplexing
* of the hotplug directories.
* For now look if the kernel calls udevsend instead of /sbin/hotplug,
* or the uevent-helper in /proc/sys/kernel/hotplug is empty.
*/
static int manage_hotplug_event(void) {
char helper[256];
@ -70,13 +72,15 @@ static int manage_hotplug_event(void) {
if (fd < 0)
return 0;
len = read(fd, helper, 256);
len = read(fd, helper, sizeof(helper)-1);
close(fd);
if (len < 0)
return 0;
helper[len] = '\0';
if (helper[0] == '\0' || helper[0] == '\n')
return 1;
if (strstr(helper, "udevsend"))
return 1;

196
udevd.c
View File

@ -38,6 +38,7 @@
#include <sys/un.h>
#include <sys/sysinfo.h>
#include <sys/stat.h>
#include <linux/netlink.h>
#include "list.h"
#include "udev_libc_wrapper.h"
@ -49,6 +50,7 @@
/* global variables*/
static int udevsendsock;
static int ueventsock;
static pid_t sid;
static int pipefds[2];
@ -126,7 +128,8 @@ static void msg_queue_insert(struct hotplug_msg *msg)
break;
if (loop_msg->seqnum == msg->seqnum) {
info("ignoring duplicate message seq %llu", msg->seqnum);
dbg("ignoring duplicate message seq %llu", msg->seqnum);
free(msg);
return;
}
}
@ -154,6 +157,8 @@ static void execute_udev(struct hotplug_msg *msg)
switch (pid) {
case 0:
/* child */
if (ueventsock != -1)
close(ueventsock);
close(udevsendsock);
logging_close();
@ -416,13 +421,60 @@ recheck:
}
}
static struct hotplug_msg *get_msg_from_envbuf(const char *buf, int buf_size)
{
int bufpos;
int i;
struct hotplug_msg *msg;
msg = malloc(sizeof(struct hotplug_msg) + buf_size);
if (msg == NULL)
return NULL;
memset(msg, 0x00, sizeof(struct hotplug_msg) + buf_size);
/* copy environment buffer and reconstruct envp */
memcpy(msg->envbuf, buf, buf_size);
bufpos = 0;
for (i = 0; (bufpos < buf_size) && (i < HOTPLUG_NUM_ENVP-2); i++) {
int keylen;
char *key;
key = &msg->envbuf[bufpos];
keylen = strlen(key);
msg->envp[i] = key;
bufpos += keylen + 1;
dbg("add '%s' to msg.envp[%i]", msg->envp[i], i);
/* remember some keys for further processing */
if (strncmp(key, "ACTION=", 7) == 0)
msg->action = &key[7];
if (strncmp(key, "DEVPATH=", 8) == 0)
msg->devpath = &key[8];
if (strncmp(key, "SUBSYSTEM=", 10) == 0)
msg->subsystem = &key[10];
if (strncmp(key, "SEQNUM=", 7) == 0)
msg->seqnum = strtoull(&key[7], NULL, 10);
if (strncmp(key, "PHYSDEVPATH=", 12) == 0)
msg->physdevpath = &key[12];
if (strncmp(key, "TIMEOUT=", 8) == 0)
msg->timeout = strtoull(&key[8], NULL, 10);
}
msg->envp[i++] = "UDEVD_EVENT=1";
msg->envp[i] = NULL;
return msg;
}
/* receive the udevsend message and do some sanity checks */
static struct hotplug_msg *get_udevsend_msg(void)
{
static struct udevsend_msg usend_msg;
struct hotplug_msg *msg;
int bufpos;
int i;
ssize_t size;
struct msghdr smsg;
struct cmsghdr *cmsg;
@ -467,46 +519,60 @@ static struct hotplug_msg *get_udevsend_msg(void)
envbuf_size = size - offsetof(struct udevsend_msg, envbuf);
dbg("envbuf_size=%i", envbuf_size);
msg = malloc(sizeof(struct hotplug_msg) + envbuf_size);
msg = get_msg_from_envbuf(usend_msg.envbuf, envbuf_size);
if (msg == NULL)
return NULL;
memset(msg, 0x00, sizeof(struct hotplug_msg) + envbuf_size);
return msg;
}
/* copy environment buffer and reconstruct envp */
memcpy(msg->envbuf, usend_msg.envbuf, envbuf_size);
bufpos = 0;
for (i = 0; (bufpos < envbuf_size) && (i < HOTPLUG_NUM_ENVP-2); i++) {
int keylen;
char *key;
/* receive the kernel user event message and do some sanity checks */
static struct hotplug_msg *get_uevent_msg(void)
{
struct hotplug_msg *msg;
int bufpos;
ssize_t size;
static char buffer[HOTPLUG_BUFFER_SIZE + 512];
char *pos;
key = &msg->envbuf[bufpos];
keylen = strlen(key);
msg->envp[i] = key;
bufpos += keylen + 1;
dbg("add '%s' to msg.envp[%i]", msg->envp[i], i);
/* remember some keys for further processing */
if (strncmp(key, "ACTION=", 7) == 0)
msg->action = &key[7];
if (strncmp(key, "DEVPATH=", 8) == 0)
msg->devpath = &key[8];
if (strncmp(key, "SUBSYSTEM=", 10) == 0)
msg->subsystem = &key[10];
if (strncmp(key, "SEQNUM=", 7) == 0)
msg->seqnum = strtoull(&key[7], NULL, 10);
if (strncmp(key, "PHYSDEVPATH=", 12) == 0)
msg->physdevpath = &key[12];
if (strncmp(key, "TIMEOUT=", 8) == 0)
msg->timeout = strtoull(&key[8], NULL, 10);
size = recv(ueventsock, &buffer, sizeof(buffer), 0);
if (size < 0) {
if (errno != EINTR)
dbg("unable to receive udevsend message");
return NULL;
}
if ((size_t)size > sizeof(buffer)-1)
size = sizeof(buffer)-1;
buffer[size] = '\0';
dbg("uevent_size=%i", size);
/* start of event payload */
bufpos = strlen(buffer)+1;
msg = get_msg_from_envbuf(&buffer[bufpos], size-bufpos);
if (msg == NULL)
return NULL;
/* validate message */
pos = strchr(buffer, '@');
if (pos == NULL) {
dbg("invalid uevent '%s'", buffer);
free(msg);
return NULL;
}
pos[0] = '\0';
if (msg->action == NULL) {
dbg("no ACTION in payload found, skip event '%s'", buffer);
free(msg);
return NULL;
}
if (strcmp(msg->action, buffer) != 0) {
dbg("ACTION in payload does not match uevent, skip event '%s'", buffer);
free(msg);
return NULL;
}
msg->envp[i++] = "UDEVD_EVENT=1";
msg->envp[i] = NULL;
return msg;
}
@ -622,6 +688,34 @@ static int init_udevsend_socket(void)
return 0;
}
static int init_uevent_socket(void)
{
struct sockaddr_nl snl;
int retval;
memset(&snl, 0x00, sizeof(struct sockaddr_nl));
snl.nl_family = AF_NETLINK;
snl.nl_pid = getpid();
snl.nl_groups = 0xffffffff;
ueventsock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
if (ueventsock == -1) {
dbg("error getting socket, %s", strerror(errno));
return -1;
}
retval = bind(ueventsock, (struct sockaddr *) &snl,
sizeof(struct sockaddr_nl));
if (retval < 0) {
dbg("bind failed, %s", strerror(errno));
close(ueventsock);
ueventsock = -1;
return -1;
}
return 0;
}
int main(int argc, char *argv[], char *envp[])
{
struct sysinfo info;
@ -631,6 +725,7 @@ int main(int argc, char *argv[], char *envp[])
struct sigaction act;
fd_set readfds;
const char *udevd_expected_seqnum;
int uevent_active = 0;
logging_init("udevd");
udev_init_config();
@ -716,6 +811,10 @@ int main(int argc, char *argv[], char *envp[])
sigaction(SIGALRM, &act, NULL);
sigaction(SIGCHLD, &act, NULL);
if (init_uevent_socket() < 0) {
dbg("uevent socket not available");
}
if (init_udevsend_socket() < 0) {
if (errno == EADDRINUSE)
dbg("another udevd running, exit");
@ -745,6 +844,8 @@ int main(int argc, char *argv[], char *envp[])
FD_ZERO(&readfds);
FD_SET(udevsendsock, &readfds);
if (ueventsock != -1)
FD_SET(ueventsock, &readfds);
FD_SET(pipefds[0], &readfds);
maxsockplus = udevsendsock+1;
while (1) {
@ -761,8 +862,27 @@ int main(int argc, char *argv[], char *envp[])
if (FD_ISSET(udevsendsock, &workreadfds)) {
msg = get_udevsend_msg();
if (msg)
if (msg) {
/* discard kernel messages if netlink is active */
if (uevent_active && msg->seqnum != 0) {
dbg("skip kernel udevsend message, netlink is active");
free(msg);
continue;
}
msg_queue_insert(msg);
}
}
if (FD_ISSET(ueventsock, &workreadfds)) {
msg = get_uevent_msg();
if (msg) {
msg_queue_insert(msg);
/* disable udevsend with first netlink message */
if (!uevent_active) {
info("netlink message received, disable kernel udevsend messages");
uevent_active = 1;
}
}
}
if (FD_ISSET(pipefds[0], &workreadfds))