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-rw-r--r--session/CMakeLists.txt1
-rw-r--r--session/direct-ipc.c241
-rw-r--r--session/direct.c274
3 files changed, 291 insertions, 225 deletions
diff --git a/session/CMakeLists.txt b/session/CMakeLists.txt
index d79991ee..bacd412f 100644
--- a/session/CMakeLists.txt
+++ b/session/CMakeLists.txt
@@ -6,6 +6,7 @@ include_directories(
set(sources
session.c
direct.c
+ direct-ipc.c
)
set(libs
diff --git a/session/direct-ipc.c b/session/direct-ipc.c
new file mode 100644
index 00000000..ef8de68c
--- /dev/null
+++ b/session/direct-ipc.c
@@ -0,0 +1,241 @@
+#define _POSIX_C_SOURCE 200809L
+#include <errno.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/sysmacros.h>
+#include <sys/wait.h>
+#include <xf86drm.h>
+#include <linux/major.h>
+#include <wlr/util/log.h>
+#include "session/direct-ipc.h"
+
+enum { DRM_MAJOR = 226 };
+
+#ifdef HAS_LIBCAP
+#include <sys/capability.h>
+
+static bool have_permissions(void) {
+ cap_t cap = cap_get_proc();
+ cap_flag_value_t val;
+
+ if (!cap || cap_get_flag(cap, CAP_SYS_ADMIN, CAP_PERMITTED, &val) || val != CAP_SET) {
+ wlr_log(L_ERROR, "Do not have CAP_SYS_ADMIN; cannot become DRM master");
+ cap_free(cap);
+ return false;
+ }
+
+ cap_free(cap);
+ return true;
+}
+#else
+static bool have_permissions(void) {
+ if (geteuid() != 0) {
+ wlr_log(L_ERROR, "Do not have root privileges; cannot become DRM master");
+ return false;
+ }
+
+ return true;
+}
+#endif
+
+static void send_msg(int sock, int fd, void *buf, size_t buf_len) {
+ char control[CMSG_SPACE(sizeof(fd))] = {0};
+ struct iovec iovec = { .iov_base = buf, .iov_len = buf_len };
+ struct msghdr msghdr = {0};
+
+ if (buf) {
+ msghdr.msg_iov = &iovec;
+ msghdr.msg_iovlen = 1;
+ }
+
+ if (fd >= 0) {
+ msghdr.msg_control = &control;
+ msghdr.msg_controllen = sizeof(control);
+
+ struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msghdr);
+ *cmsg = (struct cmsghdr) {
+ .cmsg_level = SOL_SOCKET,
+ .cmsg_type = SCM_RIGHTS,
+ .cmsg_len = CMSG_LEN(sizeof(fd)),
+ };
+ *(int *)CMSG_DATA(cmsg) = fd;
+ }
+
+ ssize_t ret;
+ do {
+ ret = sendmsg(sock, &msghdr, 0);
+ } while (ret < 0 && errno == EINTR);
+}
+
+static ssize_t recv_msg(int sock, int *fd_out, void *buf, size_t buf_len) {
+ char control[CMSG_SPACE(sizeof(*fd_out))] = {0};
+ struct iovec iovec = { .iov_base = buf, .iov_len = buf_len };
+ struct msghdr msghdr = {0};
+
+ if (buf) {
+ msghdr.msg_iov = &iovec;
+ msghdr.msg_iovlen = 1;
+ }
+
+ if (fd_out) {
+ msghdr.msg_control = &control;
+ msghdr.msg_controllen = sizeof(control);
+ }
+
+ ssize_t ret;
+ do {
+ ret = recvmsg(sock, &msghdr, MSG_CMSG_CLOEXEC);
+ } while (ret < 0 && errno == EINTR);
+
+ if (fd_out) {
+ struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msghdr);
+ *fd_out = cmsg ? *(int *)CMSG_DATA(cmsg) : -1;
+ }
+
+ return ret;
+}
+
+enum msg_type {
+ MSG_OPEN,
+ MSG_SETMASTER,
+ MSG_DROPMASTER,
+ MSG_END,
+};
+
+struct msg {
+ enum msg_type type;
+ char path[256];
+};
+
+static void communicate(int sock) {
+ struct msg msg;
+ int drm_fd = -1;
+ bool running = true;
+
+ while (running && recv_msg(sock, NULL, &msg, sizeof(msg)) >= 0) {
+ switch (msg.type) {
+ case MSG_OPEN:
+ errno = 0;
+
+ // These are the same flags that logind opens files with
+ int fd = open(msg.path, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK);
+ int ret = errno;
+ if (fd == -1) {
+ goto error;
+ }
+
+ struct stat st;
+ if (fstat(fd, &st) < 0) {
+ ret = errno;
+ goto error;
+ }
+
+ uint32_t maj = major(st.st_rdev);
+ if (maj != INPUT_MAJOR && maj != DRM_MAJOR) {
+ ret = ENOTSUP;
+ goto error;
+ }
+
+ if (maj == DRM_MAJOR) {
+ if (drmSetMaster(fd)) {
+ ret = errno;
+ } else {
+ drm_fd = fd;
+ }
+ }
+error:
+ send_msg(sock, ret ? -1 : fd, &ret, sizeof(ret));
+
+ if (fd != drm_fd) {
+ close(fd);
+ }
+
+ break;
+
+ case MSG_SETMASTER:
+ drmSetMaster(drm_fd);
+ send_msg(sock, -1, NULL, 0);
+ break;
+
+ case MSG_DROPMASTER:
+ drmDropMaster(drm_fd);
+ send_msg(sock, -1, NULL, 0);
+ break;
+
+ case MSG_END:
+ running = false;
+ send_msg(sock, -1, NULL, 0);
+ break;
+ }
+ }
+
+ close(drm_fd);
+ close(sock);
+}
+
+int direct_ipc_open(int sock, const char *path) {
+ struct msg msg = { .type = MSG_OPEN };
+ snprintf(msg.path, sizeof(msg.path), "%s", path);
+
+ send_msg(sock, -1, &msg, sizeof(msg));
+
+ int fd, err;
+ recv_msg(sock, &fd, &err, sizeof(err));
+
+ return err ? -err : fd;
+}
+
+void direct_ipc_setmaster(int sock) {
+ struct msg msg = { .type = MSG_SETMASTER };
+
+ send_msg(sock, -1, &msg, sizeof(msg));
+ recv_msg(sock, NULL, NULL, 0);
+}
+
+void direct_ipc_dropmaster(int sock) {
+ struct msg msg = { .type = MSG_DROPMASTER };
+
+ send_msg(sock, -1, &msg, sizeof(msg));
+ recv_msg(sock, NULL, NULL, 0);
+}
+
+void direct_ipc_finish(int sock, pid_t pid) {
+ struct msg msg = { .type = MSG_END };
+
+ send_msg(sock, -1, &msg, sizeof(msg));
+ recv_msg(sock, NULL, NULL, 0);
+
+ waitpid(pid, NULL, 0);
+}
+
+int direct_ipc_start(pid_t *pid_out) {
+ if (!have_permissions()) {
+ return -1;
+ }
+
+ int sock[2];
+ if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, sock) < 0) {
+ wlr_log_errno(L_ERROR, "Failed to create socket pair");
+ return -1;
+ }
+
+ pid_t pid = fork();
+ if (pid < 0) {
+ wlr_log_errno(L_ERROR, "Fork failed");
+ close(sock[0]);
+ close(sock[1]);
+ return -1;
+ } else if (pid == 0) {
+ close(sock[0]);
+ communicate(sock[1]);
+ _Exit(0);
+ }
+
+ close(sock[1]);
+ *pid_out = pid;
+ return sock[0];
+}
diff --git a/session/direct.c b/session/direct.c
index 3932af68..23ce1ee1 100644
--- a/session/direct.c
+++ b/session/direct.c
@@ -3,25 +3,19 @@
#include <stdlib.h>
#include <stdio.h>
#include <stdbool.h>
-#include <string.h>
-#include <fcntl.h>
#include <unistd.h>
#include <signal.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/sysmacros.h>
-#include <sys/socket.h>
-#include <sys/wait.h>
#include <linux/kd.h>
#include <linux/major.h>
+#include <linux/input.h>
#include <linux/vt.h>
#include <wayland-server.h>
-#include <xf86drm.h>
#include <wlr/session/interface.h>
#include <wlr/util/log.h>
-#ifdef HAS_LIBCAP
-#include <sys/capability.h>
-#endif
+#include "session/direct-ipc.h"
enum { DRM_MAJOR = 226 };
@@ -37,82 +31,23 @@ struct direct_session {
struct wl_event_source *vt_source;
};
-enum session_message_type {
- SESSION_OPEN,
- SESSION_SETMASTER,
- SESSION_DROPMASTER,
- SESSION_END,
-};
-
-struct session_message {
- enum session_message_type type;
- char path[60];
-};
-
-static int send_message(int sock, enum session_message_type type, const char *path) {
- struct session_message msg = {
- .type = type,
- };
- struct msghdr request = {
- .msg_iov = &(struct iovec) {
- .iov_base = &msg,
- .iov_len = sizeof(msg),
- },
- .msg_iovlen = 1,
- };
-
- if (path) {
- snprintf(msg.path, sizeof(msg.path), "%s", path);
- }
-
- sendmsg(sock, &request, 0);
-
- int err = 0, fd = -1;
- char control[CMSG_SPACE(sizeof(fd))] = {0};
- struct msghdr reply = {
- .msg_iov = &(struct iovec) {
- .iov_base = &err,
- .iov_len = sizeof(err),
- },
- .msg_iovlen = 1,
- .msg_control = control,
- .msg_controllen = sizeof(control),
- };
-
- recvmsg(sock, &reply, 0);
-
- // The other types have no meaningful return value
- if (type != SESSION_OPEN) {
- return 0;
- }
-
- struct cmsghdr *cmsg = CMSG_FIRSTHDR(&reply);
- memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd));
-
- return err ? -err : fd;
-}
-
static int direct_session_open(struct wlr_session *base, const char *path) {
struct direct_session *session = wl_container_of(base, session, base);
- struct stat st;
- if (stat(path, &st)) {
- return -errno;
- }
-
- uint32_t maj = major(st.st_rdev);
- if (maj != DRM_MAJOR && maj != INPUT_MAJOR) {
- return -EINVAL;
- }
-
- int fd = send_message(session->sock, SESSION_OPEN, path);
+ int fd = direct_ipc_open(session->sock, path);
if (fd < 0) {
wlr_log(L_ERROR, "Failed to open %s: %s%s", path, strerror(-fd),
fd == -EINVAL ? "; is another display server running?" : "");
return fd;
}
- if (maj == DRM_MAJOR) {
+ struct stat st;
+ if (fstat(fd, &st) < 0) {
+ close(fd);
+ return -errno;
+ }
+
+ if (major(st.st_rdev) == DRM_MAJOR) {
session->base.drm_fd = fd;
}
@@ -122,9 +57,18 @@ static int direct_session_open(struct wlr_session *base, const char *path) {
static void direct_session_close(struct wlr_session *base, int fd) {
struct direct_session *session = wl_container_of(base, session, base);
- if (fd == session->base.drm_fd) {
- send_message(session->sock, SESSION_DROPMASTER, NULL);
+ struct stat st;
+ if (fstat(fd, &st) < 0) {
+ wlr_log_errno(L_ERROR, "Stat failed");
+ close(fd);
+ return;
+ }
+
+ if (major(st.st_rdev) == DRM_MAJOR) {
+ direct_ipc_dropmaster(session->sock);
session->base.drm_fd = -1;
+ } else if (major(st.st_rdev) == INPUT_MAJOR) {
+ ioctl(fd, EVIOCREVOKE, 0);
}
close(fd);
@@ -151,9 +95,8 @@ static void direct_session_finish(struct wlr_session *base) {
wlr_log(L_ERROR, "Failed to restore tty");
}
- send_message(session->sock, SESSION_END, NULL);
+ direct_ipc_finish(session->sock, session->child);
close(session->sock);
- wait(NULL);
wl_event_source_remove(session->vt_source);
close(session->tty_fd);
@@ -166,11 +109,11 @@ static int vt_handler(int signo, void *data) {
if (session->base.active) {
session->base.active = false;
wl_signal_emit(&session->base.session_signal, session);
- send_message(session->sock, SESSION_DROPMASTER, NULL);
+ direct_ipc_dropmaster(session->sock);
ioctl(session->tty_fd, VT_RELDISP, 1);
} else {
ioctl(session->tty_fd, VT_RELDISP, VT_ACKACQ);
- send_message(session->sock, SESSION_SETMASTER, NULL);
+ direct_ipc_setmaster(session->sock);
session->base.active = true;
wl_signal_emit(&session->base.session_signal, session);
}
@@ -179,24 +122,22 @@ static int vt_handler(int signo, void *data) {
}
static bool setup_tty(struct direct_session *session, struct wl_display *display) {
- session->tty_fd = dup(STDIN_FILENO);
- if (session->tty_fd == -1) {
+ int fd = dup(STDIN_FILENO);
+ if (fd == -1) {
wlr_log_errno(L_ERROR, "Cannot open tty");
return false;
}
struct stat st;
- if (fstat(session->tty_fd, &st) == -1 || major(st.st_rdev) != TTY_MAJOR ||
- minor(st.st_rdev) == 0) {
+ if (fstat(fd, &st) == -1 || major(st.st_rdev) != TTY_MAJOR || minor(st.st_rdev) == 0) {
wlr_log(L_ERROR, "Not running from a virtual terminal");
goto error;
}
int tty = minor(st.st_rdev);
- int ret, kd_mode;
- session->base.vtnr = tty;
+ int ret, kd_mode, old_kbmode;
- ret = ioctl(session->tty_fd, KDGETMODE, &kd_mode);
+ ret = ioctl(fd, KDGETMODE, &kd_mode);
if (ret) {
wlr_log_errno(L_ERROR, "Failed to get tty mode");
goto error;
@@ -208,20 +149,20 @@ static bool setup_tty(struct direct_session *session, struct wl_display *display
goto error;
}
- ioctl(session->tty_fd, VT_ACTIVATE, tty);
- ioctl(session->tty_fd, VT_WAITACTIVE, tty);
+ ioctl(fd, VT_ACTIVATE, tty);
+ ioctl(fd, VT_WAITACTIVE, tty);
- if (ioctl(session->tty_fd, KDGKBMODE, &session->old_kbmode)) {
+ if (ioctl(fd, KDGKBMODE, &old_kbmode)) {
wlr_log_errno(L_ERROR, "Failed to read keyboard mode");
goto error;
}
- if (ioctl(session->tty_fd, KDSKBMODE, K_OFF)) {
+ if (ioctl(fd, KDSKBMODE, K_OFF)) {
wlr_log_errno(L_ERROR, "Failed to set keyboard mode");
goto error;
}
- if (ioctl(session->tty_fd, KDSETMODE, KD_GRAPHICS)) {
+ if (ioctl(fd, KDSETMODE, KD_GRAPHICS)) {
wlr_log_errno(L_ERROR, "Failed to set graphics mode on tty");
goto error;
}
@@ -232,7 +173,7 @@ static bool setup_tty(struct direct_session *session, struct wl_display *display
.acqsig = SIGUSR1,
};
- if (ioctl(session->tty_fd, VT_SETMODE, &mode) < 0) {
+ if (ioctl(fd, VT_SETMODE, &mode) < 0) {
wlr_log(L_ERROR, "Failed to take control of tty");
goto error;
}
@@ -244,145 +185,31 @@ static bool setup_tty(struct direct_session *session, struct wl_display *display
goto error;
}
+ session->base.vtnr = tty;
+ session->tty_fd = fd;
+ session->old_kbmode = old_kbmode;
+
return true;
error:
- close(session->tty_fd);
+ close(fd);
return false;
}
-static void communicate(int sock) {
- struct session_message msg;
- struct msghdr hdr = {
- .msg_iov = &(struct iovec) {
- .iov_base = &msg,
- .iov_len = sizeof(msg),
- },
- .msg_iovlen = 1,
- };
-
- int drm_fd = -1;
-
- while (recvmsg(sock, &hdr, 0) >= 0 || errno == EINTR) {
- switch (msg.type) {
- case SESSION_OPEN:
- errno = 0;
- // These are the flags that logind use
- int fd = open(msg.path, O_RDWR | O_CLOEXEC | O_NOCTTY | O_NONBLOCK);
- int e = errno;
-
- struct stat st;
- if (fstat(fd, &st) >= 0 && major(st.st_rdev) == DRM_MAJOR) {
- if (drmSetMaster(fd)) {
- close(fd);
- fd = -1;
- e = errno;
- }
-
- drm_fd = fd;
- }
-
- char control[CMSG_SPACE(sizeof(fd))] = {0};
- struct msghdr reply = {
- .msg_iov = &(struct iovec) {
- .iov_base = &e,
- .iov_len = sizeof(e),
- },
- .msg_iovlen = 1,
- .msg_control = &control,
- .msg_controllen = sizeof(control),
- };
- struct cmsghdr *cmsg = CMSG_FIRSTHDR(&reply);
- cmsg->cmsg_level = SOL_SOCKET;
- cmsg->cmsg_type = SCM_RIGHTS;
- cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
- memcpy(CMSG_DATA(cmsg), &fd, sizeof(fd));
-
- sendmsg(sock, &reply, 0);
- break;
- case SESSION_SETMASTER:
- if (drm_fd != -1) {
- drmSetMaster(drm_fd);
- }
-
- sendmsg(sock, &(struct msghdr){0}, 0);
- break;
- case SESSION_DROPMASTER:
- if (drm_fd != -1) {
- drmDropMaster(drm_fd);
- }
-
- sendmsg(sock, &(struct msghdr){0}, 0);
- break;
- case SESSION_END:
- sendmsg(sock, &(struct msghdr){0}, 0);
- return;
- }
- }
-}
-
-#ifdef HAS_LIBCAP
-static bool have_permissions(void) {
- cap_t cap = cap_get_proc();
- cap_flag_value_t val;
-
- if (!cap || cap_get_flag(cap, CAP_SYS_ADMIN, CAP_PERMITTED, &val) || val != CAP_SET) {
- wlr_log(L_ERROR, "Do not have CAP_SYS_ADMIN; cannot become DRM master");
- cap_free(cap);
- return false;
- }
-
- cap_free(cap);
- return true;
-}
-#else
-static bool have_permissions(void) {
- if (geteuid() != 0) {
- wlr_log(L_ERROR, "Do not have root privileges; cannot become DRM master");
- return false;
- }
-
- return true;
-}
-#endif
-
static struct wlr_session *direct_session_start(struct wl_display *disp) {
- if (!have_permissions()) {
- return NULL;
- }
-
- int sock[2];
- if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, sock) < 0) {
- wlr_log_errno(L_ERROR, "Failed to create socket pair");
- return NULL;
- }
-
- pid_t pid = fork();
- if (pid < 0) {
- wlr_log_errno(L_ERROR, "Fork failed");
- goto error_sock;
- } else if (pid == 0) {
- close(sock[0]);
-
- communicate(sock[1]);
-
- _Exit(0);
- }
-
- close(sock[1]);
- sock[1] = -1;
-
struct direct_session *session = calloc(1, sizeof(*session));
if (!session) {
wlr_log_errno(L_ERROR, "Allocation failed");
- goto error_child;
+ return NULL;
}
- session->child = pid;
- session->sock = sock[0];
+ session->sock = direct_ipc_start(&session->child);
+ if (session->sock == -1) {
+ goto error_session;
+ }
if (!setup_tty(session, disp)) {
- goto error_session;
+ goto error_ipc;
}
// XXX: Is it okay to trust the environment like this?
@@ -400,14 +227,11 @@ static struct wlr_session *direct_session_start(struct wl_display *disp) {
wl_signal_init(&session->base.session_signal);
return &session->base;
+error_ipc:
+ direct_ipc_finish(session->sock, session->child);
+ close(session->sock);
error_session:
free(session);
-error_child:
- send_message(sock[0], SESSION_END, NULL);
- wait(NULL);
-error_sock:
- close(sock[0]);
- close(sock[1]);
return NULL;
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-09-20 12:43:30 +0000