chiark / gitweb /
libudev: ctrl - log accept4() errors
[elogind.git] / libudev / libudev-ctrl.c
index af59c36..61e0243 100644 (file)
@@ -16,6 +16,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <sys/types.h>
+#include <sys/poll.h>
 #include <sys/socket.h>
 #include <sys/un.h>
 
@@ -33,7 +34,8 @@ enum udev_ctrl_msg_type {
        UDEV_CTRL_RELOAD_RULES,
        UDEV_CTRL_SET_ENV,
        UDEV_CTRL_SET_CHILDREN_MAX,
-       UDEV_CTRL_SETTLE,
+       UDEV_CTRL_PING,
+       UDEV_CTRL_EXIT,
 };
 
 struct udev_ctrl_msg_wire {
@@ -48,9 +50,8 @@ struct udev_ctrl_msg_wire {
 
 struct udev_ctrl_msg {
        int refcount;
-       struct udev_ctrl *uctrl;
+       struct udev_ctrl_connection *conn;
        struct udev_ctrl_msg_wire ctrl_msg_wire;
-       pid_t pid;
 };
 
 struct udev_ctrl {
@@ -59,9 +60,17 @@ struct udev_ctrl {
        int sock;
        struct sockaddr_un saddr;
        socklen_t addrlen;
+       bool bound;
+       bool connected;
 };
 
-struct udev_ctrl *udev_ctrl_new_from_socket(struct udev *udev, const char *socket_path)
+struct udev_ctrl_connection {
+       int refcount;
+       struct udev_ctrl *uctrl;
+       int sock;
+};
+
+static struct udev_ctrl *udev_ctrl_new(struct udev *udev)
 {
        struct udev_ctrl *uctrl;
 
@@ -70,12 +79,27 @@ struct udev_ctrl *udev_ctrl_new_from_socket(struct udev *udev, const char *socke
                return NULL;
        uctrl->refcount = 1;
        uctrl->udev = udev;
+       return uctrl;
+}
+
+struct udev_ctrl *udev_ctrl_new_from_socket_fd(struct udev *udev, const char *socket_path, int fd)
+{
+       struct udev_ctrl *uctrl;
 
-       uctrl->sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
-       if (uctrl->sock < 0) {
-               err(udev, "error getting socket: %m\n");
-               udev_ctrl_unref(uctrl);
+       uctrl = udev_ctrl_new(udev);
+       if (uctrl == NULL)
                return NULL;
+
+       if (fd < 0) {
+               uctrl->sock = socket(AF_LOCAL, SOCK_SEQPACKET|SOCK_NONBLOCK|SOCK_CLOEXEC, 0);
+               if (uctrl->sock < 0) {
+                       err(udev, "error getting socket: %m\n");
+                       udev_ctrl_unref(uctrl);
+                       return NULL;
+               }
+       } else {
+               uctrl->bound = true;
+               uctrl->sock = fd;
        }
 
        uctrl->saddr.sun_family = AF_LOCAL;
@@ -84,23 +108,35 @@ struct udev_ctrl *udev_ctrl_new_from_socket(struct udev *udev, const char *socke
        /* translate leading '@' to abstract namespace */
        if (uctrl->saddr.sun_path[0] == '@')
                uctrl->saddr.sun_path[0] = '\0';
-
        return uctrl;
 }
 
+struct udev_ctrl *udev_ctrl_new_from_socket(struct udev *udev, const char *socket_path)
+{
+       return udev_ctrl_new_from_socket_fd(udev, socket_path, -1);
+}
+
 int udev_ctrl_enable_receiving(struct udev_ctrl *uctrl)
 {
        int err;
-       const int feature_on = 1;
 
-       err= bind(uctrl->sock, (struct sockaddr *)&uctrl->saddr, uctrl->addrlen);
-       if (err < 0) {
-               err(uctrl->udev, "bind failed: %m\n");
-               return err;
+       if (!uctrl->bound) {
+               err = bind(uctrl->sock, (struct sockaddr *)&uctrl->saddr, uctrl->addrlen);
+               if (err < 0) {
+                       err = -errno;
+                       err(uctrl->udev, "bind failed: %m\n");
+                       return err;
+               }
+
+               err = listen(uctrl->sock, 0);
+               if (err < 0) {
+                       err = -errno;
+                       err(uctrl->udev, "listen failed: %m\n");
+                       return err;
+               }
+
+               uctrl->bound = true;
        }
-
-       /* enable receiving of the sender credentials */
-       setsockopt(uctrl->sock, SOL_SOCKET, SO_PASSCRED, &feature_on, sizeof(feature_on));
        return 0;
 }
 
@@ -117,16 +153,17 @@ struct udev_ctrl *udev_ctrl_ref(struct udev_ctrl *uctrl)
        return uctrl;
 }
 
-void udev_ctrl_unref(struct udev_ctrl *uctrl)
+struct udev_ctrl *udev_ctrl_unref(struct udev_ctrl *uctrl)
 {
        if (uctrl == NULL)
-               return;
+               return NULL;
        uctrl->refcount--;
        if (uctrl->refcount > 0)
-               return;
+               return uctrl;
        if (uctrl->sock >= 0)
                close(uctrl->sock);
        free(uctrl);
+       return NULL;
 }
 
 int udev_ctrl_get_fd(struct udev_ctrl *uctrl)
@@ -136,10 +173,57 @@ int udev_ctrl_get_fd(struct udev_ctrl *uctrl)
        return uctrl->sock;
 }
 
-static int ctrl_send(struct udev_ctrl *uctrl, enum udev_ctrl_msg_type type, int intval, const char *buf)
+struct udev_ctrl_connection *udev_ctrl_get_connection(struct udev_ctrl *uctrl)
+{
+       struct udev_ctrl_connection *conn;
+       const int on = 1;
+
+       conn = calloc(1, sizeof(struct udev_ctrl_connection));
+       if (conn == NULL)
+               return NULL;
+       conn->refcount = 1;
+       conn->uctrl = uctrl;
+
+       conn->sock = accept4(uctrl->sock, NULL, NULL, SOCK_CLOEXEC|SOCK_NONBLOCK);
+       if (conn->sock < 0) {
+               if (errno != EINTR)
+                       err(uctrl->udev, "unable to receive ctrl connection: %m\n");
+               free(conn);
+               return NULL;
+       }
+
+       /* enable receiving of the sender credentials */
+       setsockopt(conn->sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
+       udev_ctrl_ref(uctrl);
+       return conn;
+}
+
+struct udev_ctrl_connection *udev_ctrl_connection_ref(struct udev_ctrl_connection *conn)
+{
+       if (conn == NULL)
+               return NULL;
+       conn->refcount++;
+       return conn;
+}
+
+struct udev_ctrl_connection *udev_ctrl_connection_unref(struct udev_ctrl_connection *conn)
+{
+       if (conn == NULL)
+               return NULL;
+       conn->refcount--;
+       if (conn->refcount > 0)
+               return conn;
+       if (conn->sock >= 0)
+               close(conn->sock);
+       udev_ctrl_unref(conn->uctrl);
+       free(conn);
+       return NULL;
+}
+
+static int ctrl_send(struct udev_ctrl *uctrl, enum udev_ctrl_msg_type type, int intval, const char *buf, int timeout)
 {
        struct udev_ctrl_msg_wire ctrl_msg_wire;
-       int err;
+       int err = 0;
 
        memset(&ctrl_msg_wire, 0x00, sizeof(struct udev_ctrl_msg_wire));
        strcpy(ctrl_msg_wire.version, "udev-" VERSION);
@@ -151,51 +235,89 @@ static int ctrl_send(struct udev_ctrl *uctrl, enum udev_ctrl_msg_type type, int
        else
                ctrl_msg_wire.intval = intval;
 
-       err = sendto(uctrl->sock, &ctrl_msg_wire, sizeof(ctrl_msg_wire), 0,
-                    (struct sockaddr *)&uctrl->saddr, uctrl->addrlen);
-       if (err == -1) {
-               err(uctrl->udev, "error sending message: %m\n");
+       if (!uctrl->connected) {
+               if (connect(uctrl->sock, (struct sockaddr *)&uctrl->saddr, uctrl->addrlen) < 0) {
+                       err = -errno;
+                       goto out;
+               }
+               uctrl->connected = true;
+       }
+       if (send(uctrl->sock, &ctrl_msg_wire, sizeof(ctrl_msg_wire), 0) < 0) {
+               err = -errno;
+               goto out;
+       }
+
+       /* wait for peer message handling or disconnect */
+       for (;;) {
+               struct pollfd pfd[1];
+               int r;
+
+               pfd[0].fd = uctrl->sock;
+               pfd[0].events = POLLIN;
+               r = poll(pfd, 1, timeout * 1000);
+               if (r  < 0) {
+                       if (errno == EINTR)
+                               continue;
+                       err = -errno;
+                       break;
+               }
+
+               if (r > 0 && pfd[0].revents & POLLERR) {
+                       err = -EIO;
+                       break;
+               }
+
+               if (r == 0)
+                       err = -ETIMEDOUT;
+               break;
        }
+out:
        return err;
 }
 
-int udev_ctrl_send_set_log_level(struct udev_ctrl *uctrl, int priority)
+int udev_ctrl_send_set_log_level(struct udev_ctrl *uctrl, int priority, int timeout)
 {
-       return ctrl_send(uctrl, UDEV_CTRL_SET_LOG_LEVEL, priority, NULL);
+       return ctrl_send(uctrl, UDEV_CTRL_SET_LOG_LEVEL, priority, NULL, timeout);
 }
 
-int udev_ctrl_send_stop_exec_queue(struct udev_ctrl *uctrl)
+int udev_ctrl_send_stop_exec_queue(struct udev_ctrl *uctrl, int timeout)
 {
-       return ctrl_send(uctrl, UDEV_CTRL_STOP_EXEC_QUEUE, 0, NULL);
+       return ctrl_send(uctrl, UDEV_CTRL_STOP_EXEC_QUEUE, 0, NULL, timeout);
 }
 
-int udev_ctrl_send_start_exec_queue(struct udev_ctrl *uctrl)
+int udev_ctrl_send_start_exec_queue(struct udev_ctrl *uctrl, int timeout)
 {
-       return ctrl_send(uctrl, UDEV_CTRL_START_EXEC_QUEUE, 0, NULL);
+       return ctrl_send(uctrl, UDEV_CTRL_START_EXEC_QUEUE, 0, NULL, timeout);
 }
 
-int udev_ctrl_send_reload_rules(struct udev_ctrl *uctrl)
+int udev_ctrl_send_reload_rules(struct udev_ctrl *uctrl, int timeout)
 {
-       return ctrl_send(uctrl, UDEV_CTRL_RELOAD_RULES, 0, NULL);
+       return ctrl_send(uctrl, UDEV_CTRL_RELOAD_RULES, 0, NULL, timeout);
 }
 
-int udev_ctrl_send_set_env(struct udev_ctrl *uctrl, const char *key)
+int udev_ctrl_send_set_env(struct udev_ctrl *uctrl, const char *key, int timeout)
 {
-       return ctrl_send(uctrl, UDEV_CTRL_SET_ENV, 0, key);
+       return ctrl_send(uctrl, UDEV_CTRL_SET_ENV, 0, key, timeout);
 }
 
-int udev_ctrl_send_set_children_max(struct udev_ctrl *uctrl, int count)
+int udev_ctrl_send_set_children_max(struct udev_ctrl *uctrl, int count, int timeout)
 {
-       return ctrl_send(uctrl, UDEV_CTRL_SET_CHILDREN_MAX, count, NULL);
+       return ctrl_send(uctrl, UDEV_CTRL_SET_CHILDREN_MAX, count, NULL, timeout);
 }
 
-int udev_ctrl_send_settle(struct udev_ctrl *uctrl)
+int udev_ctrl_send_ping(struct udev_ctrl *uctrl, int timeout)
 {
-       return ctrl_send(uctrl, UDEV_CTRL_SETTLE, 0, NULL);
+       return ctrl_send(uctrl, UDEV_CTRL_PING, 0, NULL, timeout);
 }
 
-struct udev_ctrl_msg *udev_ctrl_receive_msg(struct udev_ctrl *uctrl)
+int udev_ctrl_send_exit(struct udev_ctrl *uctrl, int timeout)
 {
+       return ctrl_send(uctrl, UDEV_CTRL_EXIT, 0, NULL, timeout);
+}
+
+struct udev_ctrl_msg *udev_ctrl_receive_msg(struct udev_ctrl_connection *conn)
+{
+       struct udev *udev = conn->uctrl->udev;
        struct udev_ctrl_msg *uctrl_msg;
        ssize_t size;
        struct msghdr smsg;
@@ -208,43 +330,40 @@ struct udev_ctrl_msg *udev_ctrl_receive_msg(struct udev_ctrl *uctrl)
        if (uctrl_msg == NULL)
                return NULL;
        uctrl_msg->refcount = 1;
-       uctrl_msg->uctrl = uctrl;
+       uctrl_msg->conn = conn;
+       udev_ctrl_connection_ref(conn);
 
        iov.iov_base = &uctrl_msg->ctrl_msg_wire;
        iov.iov_len = sizeof(struct udev_ctrl_msg_wire);
-
        memset(&smsg, 0x00, sizeof(struct msghdr));
        smsg.msg_iov = &iov;
        smsg.msg_iovlen = 1;
        smsg.msg_control = cred_msg;
        smsg.msg_controllen = sizeof(cred_msg);
-
-       size = recvmsg(uctrl->sock, &smsg, 0);
+       size = recvmsg(conn->sock, &smsg, 0);
        if (size <  0) {
-               err(uctrl->udev, "unable to receive user udevd message: %m\n");
+               err(udev, "unable to receive user udevd message: %m\n");
                goto err;
        }
        cmsg = CMSG_FIRSTHDR(&smsg);
        cred = (struct ucred *) CMSG_DATA(cmsg);
 
        if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) {
-               err(uctrl->udev, "no sender credentials received, message ignored\n");
+               err(udev, "no sender credentials received, message ignored\n");
                goto err;
        }
 
        if (cred->uid != 0) {
-               err(uctrl->udev, "sender uid=%i, message ignored\n", cred->uid);
+               err(udev, "sender uid=%i, message ignored\n", cred->uid);
                goto err;
        }
 
-       uctrl_msg->pid = cred->pid;
-
        if (uctrl_msg->ctrl_msg_wire.magic != UDEV_CTRL_MAGIC) {
-               err(uctrl->udev, "message magic 0x%08x doesn't match, ignore it\n", uctrl_msg->ctrl_msg_wire.magic);
+               err(udev, "message magic 0x%08x doesn't match, ignore it\n", uctrl_msg->ctrl_msg_wire.magic);
                goto err;
        }
 
-       dbg(uctrl->udev, "created ctrl_msg %p (%i)\n", uctrl_msg, uctrl_msg->ctrl_msg_wire.type);
+       dbg(udev, "created ctrl_msg %p (%i)\n", uctrl_msg, uctrl_msg->ctrl_msg_wire.type);
        return uctrl_msg;
 err:
        udev_ctrl_msg_unref(uctrl_msg);
@@ -259,15 +378,17 @@ struct udev_ctrl_msg *udev_ctrl_msg_ref(struct udev_ctrl_msg *ctrl_msg)
        return ctrl_msg;
 }
 
-void udev_ctrl_msg_unref(struct udev_ctrl_msg *ctrl_msg)
+struct udev_ctrl_msg *udev_ctrl_msg_unref(struct udev_ctrl_msg *ctrl_msg)
 {
        if (ctrl_msg == NULL)
-               return;
+               return NULL;
        ctrl_msg->refcount--;
        if (ctrl_msg->refcount > 0)
-               return;
-       dbg(ctrl_msg->uctrl->udev, "release ctrl_msg %p\n", ctrl_msg);
+               return ctrl_msg;
+       dbg(ctrl_msg->conn->uctrl->udev, "release ctrl_msg %p\n", ctrl_msg);
+       udev_ctrl_connection_unref(ctrl_msg->conn);
        free(ctrl_msg);
+       return NULL;
 }
 
 int udev_ctrl_get_set_log_level(struct udev_ctrl_msg *ctrl_msg)
@@ -312,9 +433,16 @@ int udev_ctrl_get_set_children_max(struct udev_ctrl_msg *ctrl_msg)
        return -1;
 }
 
-pid_t udev_ctrl_get_settle(struct udev_ctrl_msg *ctrl_msg)
+int udev_ctrl_get_ping(struct udev_ctrl_msg *ctrl_msg)
 {
-       if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_SETTLE)
-               return ctrl_msg->pid;
+       if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_PING)
+               return 1;
+       return -1;
+}
+
+int udev_ctrl_get_exit(struct udev_ctrl_msg *ctrl_msg)
+{
+       if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_EXIT)
+               return 1;
        return -1;
 }