/*
* libudev - interface to udev device information
*
- * Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
+ * Copyright (C) 2008-2009 Kay Sievers <kay.sievers@vrfy.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
#include <errno.h>
#include <string.h>
#include <dirent.h>
+#include <sys/poll.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/un.h>
+#include <arpa/inet.h>
#include <linux/netlink.h>
+#include <linux/filter.h>
#include "libudev.h"
#include "libudev-private.h"
int refcount;
int sock;
struct sockaddr_nl snl;
- struct sockaddr_nl snl_peer;
+ struct sockaddr_nl snl_trusted_sender;
+ struct sockaddr_nl snl_destination;
struct sockaddr_un sun;
socklen_t addrlen;
+ struct udev_list_node filter_subsystem_list;
};
enum udev_monitor_netlink_group {
- UDEV_MONITOR_KERNEL = 1,
- UDEV_MONITOR_UDEV = 2,
+ UDEV_MONITOR_NONE,
+ UDEV_MONITOR_KERNEL,
+ UDEV_MONITOR_UDEV,
};
+#define UDEV_MONITOR_MAGIC 0xcafe1dea
+struct udev_monitor_netlink_header {
+ /* udev version text */
+ char version[16];
+ /*
+ * magic to protect against daemon <-> library message format mismatch
+ * used in the kernel from socket filter rules; needs to be stored in network order
+ */
+ unsigned int magic;
+ /* properties buffer */
+ unsigned short properties_off;
+ unsigned short properties_len;
+ /*
+ * hashes of some common device properties strings to filter with socket filters in
+ * the client used in the kernel from socket filter rules; needs to be stored in
+ * network order
+ */
+ unsigned int filter_subsystem;
+ unsigned int filter_devtype;
+};
+
+static struct udev_monitor *udev_monitor_new(struct udev *udev)
+{
+ struct udev_monitor *udev_monitor;
+
+ udev_monitor = calloc(1, sizeof(struct udev_monitor));
+ if (udev_monitor == NULL)
+ return NULL;
+ udev_monitor->refcount = 1;
+ udev_monitor->udev = udev;
+ udev_list_init(&udev_monitor->filter_subsystem_list);
+ return udev_monitor;
+}
+
/**
* udev_monitor_new_from_socket:
* @udev: udev library context
return NULL;
if (socket_path == NULL)
return NULL;
- udev_monitor = calloc(1, sizeof(struct udev_monitor));
+ udev_monitor = udev_monitor_new(udev);
if (udev_monitor == NULL)
return NULL;
- udev_monitor->refcount = 1;
- udev_monitor->udev = udev;
udev_monitor->sun.sun_family = AF_LOCAL;
if (socket_path[0] == '@') {
/* translate leading '@' to abstract namespace */
- util_strlcpy(udev_monitor->sun.sun_path, socket_path, sizeof(udev_monitor->sun.sun_path));
+ util_strscpy(udev_monitor->sun.sun_path, sizeof(udev_monitor->sun.sun_path), socket_path);
udev_monitor->sun.sun_path[0] = '\0';
udev_monitor->addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(socket_path);
} else if (stat(socket_path, &statbuf) == 0 && S_ISSOCK(statbuf.st_mode)) {
/* existing socket file */
- util_strlcpy(udev_monitor->sun.sun_path, socket_path, sizeof(udev_monitor->sun.sun_path));
+ util_strscpy(udev_monitor->sun.sun_path, sizeof(udev_monitor->sun.sun_path), socket_path);
udev_monitor->addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(socket_path);
} else {
/* no socket file, assume abstract namespace socket */
- util_strlcpy(&udev_monitor->sun.sun_path[1], socket_path, sizeof(udev_monitor->sun.sun_path)-1);
+ util_strscpy(&udev_monitor->sun.sun_path[1], sizeof(udev_monitor->sun.sun_path)-1, socket_path);
udev_monitor->addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(socket_path)+1;
}
udev_monitor->sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
return NULL;
if (name == NULL)
- return NULL;
- if (strcmp(name, "kernel") == 0)
- group = UDEV_MONITOR_KERNEL;
+ group = UDEV_MONITOR_NONE;
else if (strcmp(name, "udev") == 0)
group = UDEV_MONITOR_UDEV;
+ else if (strcmp(name, "kernel") == 0)
+ group = UDEV_MONITOR_KERNEL;
else
return NULL;
- udev_monitor = calloc(1, sizeof(struct udev_monitor));
+ udev_monitor = udev_monitor_new(udev);
if (udev_monitor == NULL)
return NULL;
- udev_monitor->refcount = 1;
- udev_monitor->udev = udev;
udev_monitor->sock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
if (udev_monitor->sock == -1) {
udev_monitor->snl.nl_family = AF_NETLINK;
udev_monitor->snl.nl_groups = group;
- udev_monitor->snl_peer.nl_family = AF_NETLINK;
- udev_monitor->snl_peer.nl_groups = UDEV_MONITOR_UDEV;
+
+ /* default destination for sending */
+ udev_monitor->snl_destination.nl_family = AF_NETLINK;
+ udev_monitor->snl_destination.nl_groups = UDEV_MONITOR_UDEV;
dbg(udev, "monitor %p created with NETLINK_KOBJECT_UEVENT (%u)\n", udev_monitor, group);
return udev_monitor;
}
+static inline void bpf_stmt(struct sock_filter *inss, unsigned int *i,
+ unsigned short code, unsigned int data)
+{
+ struct sock_filter *ins = &inss[*i];
+
+ ins->code = code;
+ ins->k = data;
+ (*i)++;
+}
+
+static inline void bpf_jmp(struct sock_filter *inss, unsigned int *i,
+ unsigned short code, unsigned int data,
+ unsigned short jt, unsigned short jf)
+{
+ struct sock_filter *ins = &inss[*i];
+
+ ins->code = code;
+ ins->jt = jt;
+ ins->jf = jf;
+ ins->k = data;
+ (*i)++;
+}
+
+int udev_monitor_filter_update(struct udev_monitor *udev_monitor)
+{
+ static struct sock_filter ins[256];
+ static struct sock_fprog filter;
+ unsigned int i;
+ struct udev_list_entry *list_entry;
+ int err;
+
+ if (udev_list_get_entry(&udev_monitor->filter_subsystem_list) == NULL)
+ return 0;
+
+ memset(ins, 0x00, sizeof(ins));
+ i = 0;
+
+ /* load magic in A */
+ bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, magic));
+ /* jump if magic matches */
+ bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, UDEV_MONITOR_MAGIC, 1, 0);
+ /* wrong magic, pass packet */
+ bpf_stmt(ins, &i, BPF_RET|BPF_K, 0xffffffff);
+
+ /* add all subsystem match values */
+ udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_monitor->filter_subsystem_list)) {
+ unsigned int hash;
+
+ /* load filter_subsystem value in A */
+ bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, filter_subsystem));
+ hash = util_string_hash32(udev_list_entry_get_name(list_entry));
+ if (udev_list_entry_get_value(list_entry) == NULL) {
+ /* jump if subsystem does not match */
+ bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, hash, 0, 1);
+ } else {
+ /* jump if subsystem does not match */
+ bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, hash, 0, 3);
+
+ /* load filter_devtype value in A */
+ bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, filter_devtype));
+ /* jump if value does not match */
+ hash = util_string_hash32(udev_list_entry_get_value(list_entry));
+ bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, hash, 0, 1);
+ }
+
+ /* matched, pass packet */
+ bpf_stmt(ins, &i, BPF_RET|BPF_K, 0xffffffff);
+
+ if (i+1 >= ARRAY_SIZE(ins))
+ return -1;
+ }
+ /* nothing matched, drop packet */
+ bpf_stmt(ins, &i, BPF_RET|BPF_K, 0);
+
+ /* install filter */
+ filter.len = i;
+ filter.filter = ins;
+ err = setsockopt(udev_monitor->sock, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter));
+ return err;
+}
+
+int udev_monitor_allow_unicast_sender(struct udev_monitor *udev_monitor, struct udev_monitor *sender)
+{
+ udev_monitor->snl_trusted_sender.nl_pid = sender->snl.nl_pid;
+ return 0;
+}
+
int udev_monitor_enable_receiving(struct udev_monitor *udev_monitor)
{
int err;
const int on = 1;
- if (udev_monitor->sun.sun_family != 0)
+ if (udev_monitor->sun.sun_family != 0) {
err = bind(udev_monitor->sock,
(struct sockaddr *)&udev_monitor->sun, udev_monitor->addrlen);
- else if (udev_monitor->snl.nl_family != 0)
+ } else if (udev_monitor->snl.nl_family != 0) {
+ udev_monitor_filter_update(udev_monitor);
err = bind(udev_monitor->sock,
(struct sockaddr *)&udev_monitor->snl, sizeof(struct sockaddr_nl));
- else
+ if (err == 0) {
+ struct sockaddr_nl snl;
+ socklen_t addrlen;
+
+ /*
+ * get the address the kernel has assigned us
+ * it is usually, but not neccessarily the pid
+ */
+ addrlen = sizeof(struct sockaddr_nl);
+ err = getsockname(udev_monitor->sock, (struct sockaddr *)&snl, &addrlen);
+ if (err == 0)
+ udev_monitor->snl.nl_pid = snl.nl_pid;
+ }
+ } else {
return -EINVAL;
+ }
if (err < 0) {
err(udev_monitor->udev, "bind failed: %m\n");
return setsockopt(udev_monitor->sock, SOL_SOCKET, SO_RCVBUFFORCE, &size, sizeof(size));
}
+int udev_monitor_disconnect(struct udev_monitor *udev_monitor)
+{
+ int err;
+
+ err = close(udev_monitor->sock);
+ udev_monitor->sock = -1;
+ return err;
+}
+
/**
* udev_monitor_ref:
* @udev_monitor: udev monitor
return;
if (udev_monitor->sock >= 0)
close(udev_monitor->sock);
+ udev_list_cleanup_entries(udev_monitor->udev, &udev_monitor->filter_subsystem_list);
dbg(udev_monitor->udev, "monitor %p released\n", udev_monitor);
free(udev_monitor);
}
return udev_monitor->sock;
}
+static int passes_filter(struct udev_monitor *udev_monitor, struct udev_device *udev_device)
+{
+ struct udev_list_entry *list_entry;
+
+ if (udev_list_get_entry(&udev_monitor->filter_subsystem_list) == NULL)
+ return 1;
+
+ udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_monitor->filter_subsystem_list)) {
+ const char *subsys = udev_list_entry_get_name(list_entry);
+ const char *dsubsys = udev_device_get_subsystem(udev_device);
+ const char *devtype;
+ const char *ddevtype;
+
+ if (strcmp(dsubsys, subsys) != 0)
+ continue;
+
+ devtype = udev_list_entry_get_value(list_entry);
+ if (devtype == NULL)
+ return 1;
+ ddevtype = udev_device_get_devtype(udev_device);
+ if (ddevtype == NULL)
+ continue;
+ if (strcmp(ddevtype, devtype) == 0)
+ return 1;
+ }
+ return 0;
+}
+
/**
* udev_monitor_receive_device:
* @udev_monitor: udev monitor
struct cmsghdr *cmsg;
struct sockaddr_nl snl;
struct ucred *cred;
- char buf[4096];
- size_t bufpos;
+ char buf[8192];
+ ssize_t buflen;
+ ssize_t bufpos;
+ struct udev_monitor_netlink_header *nlh;
int devpath_set = 0;
int subsystem_set = 0;
int action_set = 0;
int maj = 0;
int min = 0;
+ int is_kernel = 0;
+retry:
if (udev_monitor == NULL)
return NULL;
memset(buf, 0x00, sizeof(buf));
if (udev_monitor->snl.nl_family != 0) {
smsg.msg_name = &snl;
- smsg.msg_namelen = sizeof snl;
+ smsg.msg_namelen = sizeof(snl);
}
- if (recvmsg(udev_monitor->sock, &smsg, 0) < 0) {
+ buflen = recvmsg(udev_monitor->sock, &smsg, 0);
+ if (buflen < 0) {
if (errno != EINTR)
info(udev_monitor->udev, "unable to receive message\n");
return NULL;
}
+ if (buflen < 32 || (size_t)buflen >= sizeof(buf)) {
+ info(udev_monitor->udev, "invalid message length\n");
+ return NULL;
+ }
+
if (udev_monitor->snl.nl_family != 0) {
if (snl.nl_groups == 0) {
- info(udev_monitor->udev, "unicast netlink message ignored\n");
- return NULL;
- }
- if ((snl.nl_groups == UDEV_MONITOR_KERNEL) && (snl.nl_pid > 0)) {
- info(udev_monitor->udev, "multicast kernel netlink message from pid %d ignored\n", snl.nl_pid);
- return NULL;
+ /* unicast message, check if we trust the sender */
+ if (udev_monitor->snl_trusted_sender.nl_pid == 0 ||
+ snl.nl_pid != udev_monitor->snl_trusted_sender.nl_pid) {
+ info(udev_monitor->udev, "unicast netlink message ignored\n");
+ return NULL;
+ }
+ } else if (snl.nl_groups == UDEV_MONITOR_KERNEL) {
+ if (snl.nl_pid > 0) {
+ info(udev_monitor->udev, "multicast kernel netlink message from pid %d ignored\n", snl.nl_pid);
+ return NULL;
+ }
+ is_kernel = 1;
}
}
return NULL;
}
- /* skip header */
- bufpos = strlen(buf) + 1;
- if (bufpos < sizeof("a@/d") || bufpos >= sizeof(buf)) {
- info(udev_monitor->udev, "invalid message length\n");
- return NULL;
- }
+ if (strncmp(buf, "udev-", 5) == 0) {
+ /* udev message needs proper version magic */
+ nlh = (struct udev_monitor_netlink_header *) buf;
+ if (nlh->magic != htonl(UDEV_MONITOR_MAGIC))
+ return NULL;
+ if (nlh->properties_off < sizeof(struct udev_monitor_netlink_header))
+ return NULL;
+ if (nlh->properties_off+32 > buflen)
+ return NULL;
+ bufpos = nlh->properties_off;
+ } else {
+ /* kernel message with header */
+ bufpos = strlen(buf) + 1;
+ if ((size_t)bufpos < sizeof("a@/d") || bufpos >= buflen) {
+ info(udev_monitor->udev, "invalid message length\n");
+ return NULL;
+ }
- /* check message header */
- if (strstr(buf, "@/") == NULL) {
- info(udev_monitor->udev, "unrecognized message header\n");
- return NULL;
+ /* check message header */
+ if (strstr(buf, "@/") == NULL) {
+ info(udev_monitor->udev, "unrecognized message header\n");
+ return NULL;
+ }
}
udev_device = device_new(udev_monitor->udev);
return NULL;
}
- while (bufpos < sizeof(buf)) {
+ while (bufpos < buflen) {
char *key;
size_t keylen;
if (strncmp(key, "DEVPATH=", 8) == 0) {
char path[UTIL_PATH_SIZE];
- util_strlcpy(path, udev_get_sys_path(udev_monitor->udev), sizeof(path));
- util_strlcat(path, &key[8], sizeof(path));
+ util_strscpyl(path, sizeof(path), udev_get_sys_path(udev_monitor->udev), &key[8], NULL);
udev_device_set_syspath(udev_device, path);
devpath_set = 1;
} else if (strncmp(key, "SUBSYSTEM=", 10) == 0) {
} else if (strncmp(key, "DEVTYPE=", 8) == 0) {
udev_device_set_devtype(udev_device, &key[8]);
} else if (strncmp(key, "DEVNAME=", 8) == 0) {
- udev_device_set_devnode(udev_device, &key[8]);
+ if (is_kernel)
+ udev_device_set_knodename(udev_device, &key[8]);
+ else
+ udev_device_set_devnode(udev_device, &key[8]);
} else if (strncmp(key, "DEVLINKS=", 9) == 0) {
char devlinks[UTIL_PATH_SIZE];
char *slink;
char *next;
- util_strlcpy(devlinks, &key[9], sizeof(devlinks));
+ util_strscpy(devlinks, sizeof(devlinks), &key[9]);
slink = devlinks;
next = strchr(slink, ' ');
while (next != NULL) {
min = strtoull(&key[6], NULL, 10);
} else if (strncmp(key, "DEVPATH_OLD=", 12) == 0) {
udev_device_set_devpath_old(udev_device, &key[12]);
- } else if (strncmp(key, "PHYSDEVPATH=", 12) == 0) {
- udev_device_set_physdevpath(udev_device, &key[12]);
} else if (strncmp(key, "SEQNUM=", 7) == 0) {
udev_device_set_seqnum(udev_device, strtoull(&key[7], NULL, 10));
} else if (strncmp(key, "TIMEOUT=", 8) == 0) {
udev_device_set_timeout(udev_device, strtoull(&key[8], NULL, 10));
- } else if (strncmp(key, "PHYSDEV", 7) == 0) {
- /* skip deprecated values */
- continue;
} else {
udev_device_add_property_from_string(udev_device, key);
}
udev_device_unref(udev_device);
return NULL;
}
+
+ /* skip device, if it does not pass the current filter */
+ if (!passes_filter(udev_monitor, udev_device)) {
+ struct pollfd pfd[1];
+ int rc;
+
+ udev_device_unref(udev_device);
+
+ /* if something is queued, get next device */
+ pfd[0].fd = udev_monitor->sock;
+ pfd[0].events = POLLIN;
+ rc = poll(pfd, 1, 0);
+ if (rc > 0)
+ goto retry;
+ return NULL;
+ }
+
if (maj > 0)
udev_device_set_devnum(udev_device, makedev(maj, min));
udev_device_set_info_loaded(udev_device);
return udev_device;
}
-int udev_monitor_send_device(struct udev_monitor *udev_monitor, struct udev_device *udev_device)
+int udev_monitor_send_device(struct udev_monitor *udev_monitor,
+ struct udev_monitor *destination, struct udev_device *udev_device)
{
+ struct msghdr smsg;
+ struct iovec iov[2];
const char *buf;
- ssize_t len;
+ ssize_t blen;
ssize_t count;
- len = udev_device_get_properties_monitor_buf(udev_device, &buf);
- if (len < 32)
+ blen = udev_device_get_properties_monitor_buf(udev_device, &buf);
+ if (blen < 32)
return -1;
- if (udev_monitor->sun.sun_family != 0)
- count = sendto(udev_monitor->sock,
- buf, len, 0,
- (struct sockaddr *)&udev_monitor->sun,
- udev_monitor->addrlen);
- else if (udev_monitor->snl.nl_family != 0)
- /* no destination besides the muticast group, we will always get ECONNREFUSED */
- count = sendto(udev_monitor->sock,
- buf, len, 0,
- (struct sockaddr *)&udev_monitor->snl_peer,
- sizeof(struct sockaddr_nl));
- else
+
+ if (udev_monitor->sun.sun_family != 0) {
+ const char *action;
+ char header[2048];
+ char *s;
+
+ /* header <action>@<devpath> */
+ action = udev_device_get_action(udev_device);
+ if (action == NULL)
+ return -EINVAL;
+ s = header;
+ if (util_strpcpyl(&s, sizeof(header), action, "@", udev_device_get_devpath(udev_device), NULL) == 0)
+ return -EINVAL;
+ iov[0].iov_base = header;
+ iov[0].iov_len = (s - header)+1;
+
+ /* add properties list */
+ iov[1].iov_base = (char *)buf;
+ iov[1].iov_len = blen;
+
+ memset(&smsg, 0x00, sizeof(struct msghdr));
+ smsg.msg_iov = iov;
+ smsg.msg_iovlen = 2;
+ smsg.msg_name = &udev_monitor->sun;
+ smsg.msg_namelen = udev_monitor->addrlen;
+ } else if (udev_monitor->snl.nl_family != 0) {
+ const char *val;
+ struct udev_monitor_netlink_header nlh;
+
+
+ /* add versioned header */
+ memset(&nlh, 0x00, sizeof(struct udev_monitor_netlink_header));
+ util_strscpy(nlh.version, sizeof(nlh.version), "udev-" VERSION);
+ nlh.magic = htonl(UDEV_MONITOR_MAGIC);
+ val = udev_device_get_subsystem(udev_device);
+ nlh.filter_subsystem = htonl(util_string_hash32(val));
+ val = udev_device_get_devtype(udev_device);
+ if (val != NULL)
+ nlh.filter_devtype = htonl(util_string_hash32(val));
+ iov[0].iov_base = &nlh;
+ iov[0].iov_len = sizeof(struct udev_monitor_netlink_header);
+
+ /* add properties list */
+ nlh.properties_off = iov[0].iov_len;
+ nlh.properties_len = blen;
+ iov[1].iov_base = (char *)buf;
+ iov[1].iov_len = blen;
+
+ memset(&smsg, 0x00, sizeof(struct msghdr));
+ smsg.msg_iov = iov;
+ smsg.msg_iovlen = 2;
+ /*
+ * Use custom address for target, or the default one.
+ *
+ * If we send to a muticast group, we will get
+ * ECONNREFUSED, which is expected.
+ */
+ if (destination != NULL)
+ smsg.msg_name = &destination->snl;
+ else
+ smsg.msg_name = &udev_monitor->snl_destination;
+ smsg.msg_namelen = sizeof(struct sockaddr_nl);
+ } else {
return -1;
+ }
+ count = sendmsg(udev_monitor->sock, &smsg, 0);
info(udev_monitor->udev, "passed %zi bytes to monitor %p\n", count, udev_monitor);
return count;
}
+
+int udev_monitor_filter_add_match_subsystem_devtype(struct udev_monitor *udev_monitor, const char *subsystem, const char *devtype)
+{
+ if (udev_monitor == NULL)
+ return -EINVAL;
+ if (subsystem == NULL)
+ return 0;
+ if (udev_list_entry_add(udev_monitor->udev,
+ &udev_monitor->filter_subsystem_list, subsystem, devtype, 0, 0) == NULL)
+ return -ENOMEM;
+ return 0;
+}
+
+int udev_monitor_filter_remove(struct udev_monitor *udev_monitor)
+{
+ static struct sock_fprog filter = { 0, NULL };
+
+ udev_list_cleanup_entries(udev_monitor->udev, &udev_monitor->filter_subsystem_list);
+ return setsockopt(udev_monitor->sock, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter));
+}
~ianmdlvl / elogind.git / blobdiff