diff options
| -rw-r--r-- | session/direct.c | 205 |
1 files changed, 186 insertions, 19 deletions
diff --git a/session/direct.c b/session/direct.c index f3be87b6..3615aec5 100644 --- a/session/direct.c +++ b/session/direct.c @@ -1,6 +1,8 @@ #define _POSIX_C_SOURCE 200809L #include <errno.h> #include <stdlib.h> +#include <stdio.h> +#include <string.h> #include <stdbool.h> #include <string.h> #include <fcntl.h> @@ -10,6 +12,8 @@ #include <sys/stat.h> #include <sys/sysmacros.h> #include <sys/capability.h> +#include <sys/socket.h> +#include <sys/wait.h> #include <linux/kd.h> #include <linux/major.h> #include <linux/vt.h> @@ -31,32 +35,89 @@ struct direct_session { int tty_fd; int drm_fd; int kb_mode; + int sock; + pid_t child; 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 *restrict base, const char *restrict path) { struct direct_session *session = wl_container_of(base, session, base); - // These are the flags logind uses - int fd = open(path, O_RDWR | O_CLOEXEC | O_NOCTTY | O_NONBLOCK); - if (fd == -1) { - wlr_log_errno(L_ERROR, "Cannot open %s", path); + struct stat st; + if (stat(path, &st)) { return -errno; } - struct stat st; - if (fstat(fd, &st) == 0 && major(st.st_rdev) == DRM_MAJOR) { - if (drmSetMaster(fd)) { - // Save errno, in case close() clobbers it - int e = errno; - wlr_log(L_ERROR, "Cannot become DRM master: %s%s", strerror(e), - e == EINVAL ? "; is another display server running?" : ""); - close(fd); - return -e; - } + 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); + 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) { session->drm_fd = fd; } @@ -67,7 +128,7 @@ static void direct_session_close(struct wlr_session *base, int fd) { struct direct_session *session = wl_container_of(base, session, base); if (fd == session->drm_fd) { - drmDropMaster(fd); + send_message(session->sock, SESSION_DROPMASTER, NULL); session->drm_fd = -1; } @@ -91,6 +152,10 @@ static void direct_session_finish(struct wlr_session *base) { ioctl(session->tty_fd, KDSETMODE, KD_TEXT); ioctl(session->tty_fd, VT_SETMODE, &mode); + send_message(session->sock, SESSION_END, NULL); + close(session->sock); + wait(NULL); + wl_event_source_remove(session->vt_source); close(session->tty_fd); free(session); @@ -102,11 +167,11 @@ static int vt_handler(int signo, void *data) { if (session->base.active) { session->base.active = false; wl_signal_emit(&session->base.session_signal, session); - drmDropMaster(session->drm_fd); + send_message(session->sock, SESSION_DROPMASTER, NULL); ioctl(session->tty_fd, VT_RELDISP, 1); } else { ioctl(session->tty_fd, VT_RELDISP, VT_ACKACQ); - drmSetMaster(session->drm_fd); + send_message(session->sock, SESSION_SETMASTER, NULL); session->base.active = true; wl_signal_emit(&session->base.session_signal, session); } @@ -184,6 +249,78 @@ error: 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; + } + } + + +} + static struct wlr_session *direct_session_start(struct wl_display *disp) { cap_t cap = cap_get_proc(); cap_flag_value_t val; @@ -196,12 +333,36 @@ static struct wlr_session *direct_session_start(struct wl_display *disp) { cap_free(cap); + 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(L_ERROR, "Allocation failed: %s", strerror(errno)); - return NULL; + wlr_log_errno(L_ERROR, "Allocation failed"); + goto error_child; } + session->child = pid; + session->sock = sock[0]; + if (!setup_tty(session, disp)) { goto error_session; } @@ -215,6 +376,12 @@ static struct wlr_session *direct_session_start(struct wl_display *disp) { 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; } |