[PATCH] pass the whole event environment to udevd

Make _all_ hotplug variables available to the forked udev,
the udev callouts and the udev dev.d/ scripts. We put the
whole environment into a buffer and send it over the udevd
socket. udevd recreates *envp[] and passes it to the exec().
This commit is contained in:
kay.sievers@vrfy.org 2004-11-06 14:30:15 +01:00 committed by Greg KH
parent 04b49aab9a
commit 4a231017ff
3 changed files with 112 additions and 91 deletions

94
udevd.c
View File

@ -86,16 +86,6 @@ static void msg_dump_queue(void)
#endif
}
static struct hotplug_msg *msg_create(void)
{
struct hotplug_msg *new_msg;
new_msg = malloc(sizeof(struct hotplug_msg));
if (new_msg == NULL)
dbg("error malloc");
return new_msg;
}
static void run_queue_delete(struct hotplug_msg *msg)
{
list_del(&msg->list);
@ -132,22 +122,12 @@ static void msg_queue_insert(struct hotplug_msg *msg)
static void udev_run(struct hotplug_msg *msg)
{
pid_t pid;
char action[ACTION_SIZE];
char devpath[DEVPATH_SIZE];
char seqnum[SEQNUM_SIZE];
char *env[] = { action, devpath, seqnum, NULL };
snprintf(action, ACTION_SIZE-1, "ACTION=%s", msg->action);
action[ACTION_SIZE-1] = '\0';
snprintf(devpath, DEVPATH_SIZE-1, "DEVPATH=%s", msg->devpath);
devpath[DEVPATH_SIZE-1] = '\0';
sprintf(seqnum, "SEQNUM=%llu", msg->seqnum);
pid = fork();
switch (pid) {
case 0:
/* child */
execle(udev_bin, "udev", msg->subsystem, NULL, env);
execle(udev_bin, "udev", msg->subsystem, NULL, msg->envp);
dbg("exec of child failed");
_exit(1);
break;
@ -245,24 +225,23 @@ recheck:
}
/* receive the msg, do some basic sanity checks, and queue it */
static void handle_msg(int sock)
static void handle_udevsend_msg(int sock)
{
static struct udevsend_msg usend_msg;
struct hotplug_msg *msg;
int retval;
int bufpos;
int i;
ssize_t size;
struct msghdr smsg;
struct cmsghdr *cmsg;
struct iovec iov;
struct ucred *cred;
char cred_msg[CMSG_SPACE(sizeof(struct ucred))];
int envbuf_size;
msg = msg_create();
if (msg == NULL) {
dbg("unable to store message");
return;
}
iov.iov_base = msg;
iov.iov_len = sizeof(struct hotplug_msg);
memset(&usend_msg, 0x00, sizeof(struct udevsend_msg));
iov.iov_base = &usend_msg;
iov.iov_len = sizeof(struct udevsend_msg);
memset(&smsg, 0x00, sizeof(struct msghdr));
smsg.msg_iov = &iov;
@ -270,8 +249,8 @@ static void handle_msg(int sock)
smsg.msg_control = cred_msg;
smsg.msg_controllen = sizeof(cred_msg);
retval = recvmsg(sock, &smsg, 0);
if (retval < 0) {
size = recvmsg(sock, &smsg, 0);
if (size < 0) {
if (errno != EINTR)
dbg("unable to receive message");
return;
@ -281,19 +260,52 @@ static void handle_msg(int sock)
if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) {
dbg("no sender credentials received, message ignored");
goto skip;
goto exit;
}
if (cred->uid != 0) {
dbg("sender uid=%i, message ignored", cred->uid);
goto skip;
goto exit;
}
if (strncmp(msg->magic, UDEV_MAGIC, sizeof(UDEV_MAGIC)) != 0 ) {
dbg("message magic '%s' doesn't match, ignore it", msg->magic);
goto skip;
if (strncmp(usend_msg.magic, UDEV_MAGIC, sizeof(UDEV_MAGIC)) != 0 ) {
dbg("message magic '%s' doesn't match, ignore it", usend_msg.magic);
goto exit;
}
envbuf_size = size - offsetof(struct udevsend_msg, envbuf);
dbg("envbuf_size=%i", envbuf_size);
msg = malloc(sizeof(struct hotplug_msg) + envbuf_size);
memset(msg, 0x00, sizeof(struct hotplug_msg) + envbuf_size);
/* 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-1); 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);
}
msg->envp[i] = NULL;
/* if no seqnum is given, we move straight to exec queue */
if (msg->seqnum == 0) {
list_add(&msg->list, &exec_list);
@ -301,10 +313,8 @@ static void handle_msg(int sock)
} else {
msg_queue_insert(msg);
}
return;
skip:
free(msg);
exit:
return;
}
@ -511,7 +521,7 @@ int main(int argc, char *argv[], char *envp[])
}
if (FD_ISSET(ssock, &workreadfds))
handle_msg(ssock);
handle_udevsend_msg(ssock);
if (FD_ISSET(pipefds[0], &workreadfds))
user_sighandler();

19
udevd.h
View File

@ -30,14 +30,23 @@
#define SEND_WAIT_MAX_SECONDS 3
#define SEND_WAIT_LOOP_PER_SECOND 10
/* environment buffer, should match the kernel's size in lib/kobject_uevent.h */
#define HOTPLUG_BUFFER_SIZE 1024
#define HOTPLUG_NUM_ENVP 32
struct udevsend_msg {
char magic[20];
char envbuf[HOTPLUG_BUFFER_SIZE];
};
struct hotplug_msg {
char magic[20];
struct list_head list;
pid_t pid;
unsigned long long seqnum;
long queue_time;
char action[ACTION_SIZE];
char devpath[DEVPATH_SIZE];
char subsystem[SUBSYSTEM_SIZE];
char *action;
char *devpath;
char *subsystem;
unsigned long long seqnum;
char *envp[HOTPLUG_NUM_ENVP];
char envbuf[];
};

View File

@ -70,7 +70,7 @@ static int start_daemon(void)
chdir("/");
execl(UDEVD_BIN, "udevd", NULL);
dbg("exec of daemon failed");
exit(1);
_exit(1);
case -1:
dbg("fork of daemon failed");
return -1;
@ -107,51 +107,29 @@ static void run_udev(const char *subsystem)
}
}
int main(int argc, char* argv[])
int main(int argc, char *argv[], char *envp[])
{
struct hotplug_msg msg;
char *action;
char *devpath;
char *subsystem;
char *seqnum;
unsigned long long seq;
int retval = 1;
static struct udevsend_msg usend_msg;
int usend_msg_len;
int i;
int loop;
int sock = -1;
struct sockaddr_un saddr;
socklen_t addrlen;
const char *subsystem_argv;
int subsystem_env = 0;
int bufpos = 0;
int retval = 1;
int sock = -1;
int started_daemon = 0;
logging_init("udevsend");
dbg("version %s", UDEV_VERSION);
subsystem = get_subsystem(argv[1]);
if (subsystem == NULL) {
subsystem_argv = argv[1];
if (subsystem_argv == NULL) {
dbg("no subsystem");
goto exit;
}
dbg("subsystem = '%s'", subsystem);
devpath = get_devpath();
if (devpath == NULL) {
dbg("no devpath");
goto exit;
}
dbg("DEVPATH = '%s'", devpath);
action = get_action();
if (action == NULL) {
dbg("no action");
goto exit;
}
dbg("ACTION = '%s'", action);
seqnum = get_seqnum();
if (seqnum == NULL)
seq = 0;
else
seq = strtoull(seqnum, NULL, 10);
dbg("SEQNUM = '%llu'", seq);
sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
if (sock == -1) {
@ -167,25 +145,49 @@ int main(int argc, char* argv[])
strcpy(&saddr.sun_path[1], UDEVD_SOCK_PATH);
addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;
memset(&msg, 0x00, sizeof(struct hotplug_msg));
strcpy(msg.magic, UDEV_MAGIC);
msg.seqnum = seq;
strfieldcpy(msg.action, action);
strfieldcpy(msg.devpath, devpath);
strfieldcpy(msg.subsystem, subsystem);
memset(&usend_msg, 0x00, sizeof(struct udevsend_msg));
strcpy(usend_msg.magic, UDEV_MAGIC);
/* copy all keys to send buffer */
for (i = 0; envp[i]; i++) {
const char *key;
int keylen;
key = envp[i];
keylen = strlen(key);
if (bufpos + keylen >= HOTPLUG_BUFFER_SIZE-1) {
dbg("environment buffer too small, probably not called by the kernel");
continue;
}
/* older kernels do not have the SUBSYSTEM in the environment */
if (strncmp(key, "SUBSYSTEM=", 10) == 0)
subsystem_env = 1;
dbg("add '%s' to env[%i] buffer", key, i);
strcpy(&usend_msg.envbuf[bufpos], key);
bufpos += keylen + 1;
}
if (!subsystem_env) {
bufpos += sprintf(&usend_msg.envbuf[bufpos], "SUBSYSTEM=%s", subsystem_argv) + 1;
dbg("add 'SUBSYSTEM=%s' to env[%i] buffer from argv", subsystem_argv, i);
}
usend_msg_len = offsetof(struct udevsend_msg, envbuf) + bufpos;
dbg("usend_msg_len=%i", usend_msg_len);
/* If we can't send, try to start daemon and resend message */
loop = SEND_WAIT_MAX_SECONDS * SEND_WAIT_LOOP_PER_SECOND;
while (--loop) {
retval = sendto(sock, &msg, sizeof(struct hotplug_msg), 0,
(struct sockaddr *)&saddr, addrlen);
retval = sendto(sock, &usend_msg, usend_msg_len, 0, (struct sockaddr *)&saddr, addrlen);
if (retval != -1) {
retval = 0;
goto exit;
}
if (errno != ECONNREFUSED) {
dbg("error sending message");
dbg("error sending message (%s)", strerror(errno));
goto fallback;
}
@ -206,7 +208,7 @@ int main(int argc, char* argv[])
fallback:
info("unable to connect to event daemon, try to call udev directly");
run_udev(subsystem);
run_udev(subsystem_argv);
exit:
if (sock != -1)