diff options
| -rw-r--r-- | Makefile | 7 | ||||
| -rw-r--r-- | doc/protocols | 100 | ||||
| -rw-r--r-- | src/mds-kkbd.c | 3 | ||||
| -rw-r--r-- | src/mds-vt.c | 43 | ||||
| -rw-r--r-- | src/mds-vt.h | 16 |
5 files changed, 157 insertions, 12 deletions
@@ -15,6 +15,9 @@ LIBOBJ = linked-list client-list hash-table fd-table mds-message util SERVERS = mds mds-respawn mds-server mds-echo mds-registry mds-clipboard \ mds-kkbd mds-vt +# Servers that need setuid and root owner. +SETUID_SERVERS = mds mds-vt + OBJ_mds-server_ = mds-server interception-condition client multicast \ @@ -40,8 +43,8 @@ include mk/build.mk .PHONY: perms perms: all - sudo chown 'root:root' bin/mds - sudo chmod 4755 bin/mds + sudo chown 'root:root' $(foreach S,$(SETUID_SERVERS),bin/$(S)) + sudo chmod 4755 $(foreach S,$(SETUID_SERVERS),bin/$(S)) # Clean rules. diff --git a/doc/protocols b/doc/protocols index d40123b..54ace79 100644 --- a/doc/protocols +++ b/doc/protocols @@ -736,3 +736,103 @@ Compulsivity: optional --------------------------------------------------------------------- +Command: get-vt + Get the index of the virtual terminal the server is display on + and the servers file descriptor for that tty + +Required header: Client ID + Your ID, provided by `ID assignment` + in response to `Command: assign-id` + +Response: The server will response with the header `VT index` + and the index of the virtual terminal the server is + display on in decimal format. Additionally the server + will respond with the header `Active` with the value + `yes` if the VT is in the foreground or the value + `no` if the VT is in the background. + +Purpose: Allow programs to be aware of whether the display + is in the foreground or the background +Purpose: Allow programs to be aware of which VT the + server is running on +Purpose: Allow programs to gain access of the TTY associated + with the VT such that they can use ioctl and similar + calls on that TTY + +Compulsivity: required + +Reference implementation: vt + +--------------------------------------------------------------------- + +Command: configure-vt + Reconfigure the virtual terminal the server is display on + +Required header: Client ID + Your ID, provided by `ID assignment` + in response to `Command: assign-id` + +Optional header: graphical + yes) Set the TTY graphical mode + no) Set the TTY text mode + The server implementing this protocol should not set the + TTY to text mode temporarily when switching TTY. It is + up the the server that set the request for graphical mode + to temporarily switch to text mode when switching TTY. + +Optional header: exclusive + yes) The server may block other process from opening the TTY. + no) The server may not block other process from opening the TTY. + +Response: The server will response with a `Command: error` + +Purpose: Allow presentation servers to enter and leave graphical mode +Purpose: Allow programs to gain access of the TTY associated + with the VT such that they can use ioctl and similar + calls on that TTY + +Compulsivity: required + +Reference implementation: vt + +--------------------------------------------------------------------- + +Command: switching-vt + Notify servers about an ongoing virtual terminal switch + +Required header: Status + deactivating) The kernel wants to place the display in the background + activating) The kernel wants to place the display in the foreground + +Instructions: When a virtual terminal switch is requested the + server implementing control VT switching involving + the display's virtual terminal will get signaled by + the kernel. Upon this signal the server should + roadcast this command. All servers that need to + release or acquire resouces should intercept this + message with the possibility of modifying it. + Once a server is ready for the VT to switch it should + let the message pass to the next server by telling + the master server that it is no modification to do. + Once all servers are read for the switch the server + that emitted this message should signal the kernel + that it may switch VT. The server should detect + this by setting up secondary contection to the + display that intercepts this message. This connection + should intercept this message with priority −2³², + all servers that need to perform actions before the + switch takes place must have a priority higher than + −2³², preferably 0. + +Purpose: Allow servers to release resources when the user switch + virtual terminal before the terminal actually changes and + to reacquire resources when the virtual terminal become + active again + +Compulsivity: required + +Reference implementation: vt +Reference implementation: kkbd + +--------------------------------------------------------------------- + diff --git a/src/mds-kkbd.c b/src/mds-kkbd.c index b699ea0..842da90 100644 --- a/src/mds-kkbd.c +++ b/src/mds-kkbd.c @@ -16,6 +16,9 @@ * along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include "mds-kkbd.h" +/* TODO: This server should wait for `Command: get-vt` to be available, + query the active VT and connect to that TTY instead of stdin. */ +/* TODO: Release control on `Command: switching-vt`. */ #include <libmdsserver/macros.h> #include <libmdsserver/util.h> diff --git a/src/mds-vt.c b/src/mds-vt.c index 2167fb1..a6124c9 100644 --- a/src/mds-vt.c +++ b/src/mds-vt.c @@ -50,7 +50,7 @@ server_characteristics_t server_characteristics = { .require_privileges = 1, /* we want to open the new tty (the rest is fine without root for some reason) */ .require_display = 1, - .require_respawn_info = 0, + .require_respawn_info = 1, .sanity_check_argc = 1, .fork_for_safety = 0, .danger_is_deadly = 0 @@ -98,9 +98,10 @@ int initialise_server(void) const char* const message = "Command: intercept\n" "Message ID: 0\n" - "Length: 14\n" + "Length: 38\n" "\n" - "Command: echo\n"; + "Command: get-vt\n"; + "Command: configure-vt\n"; if (full_send(message, strlen(message))) return 1; @@ -337,16 +338,44 @@ int vt_set_active(int vt) /** * Open a virtual terminal * - * @param vt The index of the terminal - * @return The file descriptor for the terminal, -1 on error + * @param vt The index of the terminal + * @param old_stat Output parameter for the old file stat for the terminal + * @return The file descriptor for the terminal, -1 on error */ -int vt_open(int vt) +int vt_open(int vt, struct stat* restrict old_stat) { char vtpath[64]; /* Should be small enought and large enought for any lunatic alternative to /dev/ttyNNN, if not you will need to apply a patch (or fix your system.) */ + int fd; sprintf(vtpath, VT_PATH_PATTERN, vt); - return open(vtpath, O_RDWR); + fd = open(vtpath, O_RDWR); + if (fd < 0) + return -1; + if ((fstat(fd, old_stat) < 0) || + (fchown(fd, getuid(), getgid()) < 0)) + { + close(fd); + return -1; + } + return fd; +} + + +/** + * Close a virtual terminal + * + * @param vt The index of the terminal + * @param old_stat The old file stat for the terminal + */ +void vt_close(int fd, struct stat* restrict old_stat) +{ + if (fchown(fd, old_stat->st_uid, old_stat->st_gid) < 0) + { + xperror(*argv); + eprint("while resetting TTY ownership."); + } + close(fd); } diff --git a/src/mds-vt.h b/src/mds-vt.h index 1f87726..60204fc 100644 --- a/src/mds-vt.h +++ b/src/mds-vt.h @@ -62,10 +62,20 @@ int vt_set_active(int vt); /** * Open a virtual terminal * - * @param vt The index of the terminal - * @return The file descriptor for the terminal, -1 on error + * @param vt The index of the terminal + * @param old_stat Output parameter for the old file stat for the terminal + * @return The file descriptor for the terminal, -1 on error + */ +int vt_open(int vt, struct stat* restrict old_stat); + + +/** + * Close a virtual terminal + * + * @param vt The index of the terminal + * @param old_stat The old file stat for the terminal */ -int vt_open(int vt); +void vt_close(int fd, struct stat* restrict old_stat); |