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Commit 96fa1ff0 by Michel Normand Committed by Daniel Lezcano
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add an additionnal abstract socket to prepare for more commands

Replace the current tty service socket by a general command service socket and plug for the moment only the existing tty service. Signed-off-by: 's avatarDaniel Lezcano <dlezcano@fr.ibm.com> Signed-off-by: 's avatarMichel Normand <normand@fr.ibm.com>
parent 35be16d7
Showing with 193 additions and 65 deletions
src/lxc/Makefile.am
......@@ -19,6 +19,7 @@ pkginclude_HEADERS = \
liblxc_la_SOURCES = \
arguments.c arguments.h \
commands.h \
create.c \
destroy.c \
start.c \
......
src/lxc/commands.h 0 → 100644
/*
* lxc: linux Container library
*
* (C) Copyright IBM Corp. 2007, 2009
*
* Authors:
* Daniel Lezcano <dlezcano at fr.ibm.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef __commands_h
#define __commands_h
enum {
LXC_COMMAND_TTY,
LXC_COMMAND_MAX,
};
struct lxc_request {
int type;
int data;
};
struct lxc_answer {
int fd;
int ret; /* 0 on success, -errno on failure */
};
struct lxc_command {
struct lxc_request request;
struct lxc_answer answer;
};
#endif
src/lxc/console.c
......@@ -31,47 +31,82 @@
#include "error.h"
#include <lxc/log.h>
#include "commands.h"
lxc_log_define(lxc_console, lxc);
extern int lxc_console(const char *name, int ttynum, int *fd)
static int receive_answer(int sock, struct lxc_answer *answer)
{
int ret;
ret = lxc_af_unix_recv_fd(sock, &answer->fd, answer, sizeof(*answer));
if (ret < 0)
ERROR("failed to receive answer for the command");
return ret;
}
static int send_command(const char *name, struct lxc_command *command)
{
struct sockaddr_un addr = { 0 };
int sock, ret = -1;
char *offset = &addr.sun_path[1];
snprintf(addr.sun_path, sizeof(addr.sun_path), "@%s", name);
addr.sun_path[0] = '\0';
sock = lxc_af_unix_connect(addr.sun_path);
if (sock < 0) {
ERROR("failed to connect to the tty service");
goto out;
WARN("failed to connect to '@%s': %s", offset, strerror(errno));
return -1;
}
ret = lxc_af_unix_send_credential(sock, &ttynum, sizeof(ttynum));
ret = lxc_af_unix_send_credential(sock, &command->request,
sizeof(command->request));
if (ret < 0) {
SYSERROR("failed to send credentials");
goto out_close;
}
ret = lxc_af_unix_recv_fd(sock, fd, &ttynum, sizeof(ttynum));
if (ret < 0) {
ERROR("failed to connect to the tty");
if (ret != sizeof(command->request)) {
SYSERROR("message only partially sent to '@%s'", offset);
goto out_close;
}
INFO("tty %d allocated", ttynum);
if (!ret) {
ERROR("console denied by '%s'", name);
ret = receive_answer(sock, &command->answer);
if (ret < 0)
goto out_close;
}
ret = 0;
out:
return ret;
out_close:
close(sock);
goto out;
}
extern int lxc_console(const char *name, int ttynum, int *fd)
{
int ret;
struct lxc_command command = {
.request = { .type = LXC_COMMAND_TTY, .data = ttynum },
};
ret = send_command(name, &command);
if (ret < 0) {
ERROR("failed to send command");
return -1;
}
if (!ret) {
ERROR("console denied by '%s'", name);
return -1;
}
*fd = command.answer.fd;
if (*fd <0) {
ERROR("unable to allocate fd for tty %d", ttynum);
return -1;
}
INFO("tty %d allocated", ttynum);
return 0;
}
src/lxc/start.c
......@@ -91,6 +91,7 @@ int signalfd(int fd, const sigset_t *mask, int flags)
#include "error.h"
#include "af_unix.h"
#include "mainloop.h"
#include "commands.h"
#include <lxc/lxc.h>
#include <lxc/log.h>
......@@ -132,10 +133,10 @@ static int setup_sigchld_fd(sigset_t *oldmask)
return fd;
}
static int ttyservice_handler(int fd, void *data,
static int incoming_command_handler(int fd, void *data,
struct lxc_epoll_descr *descr);
static int tty_mainloop_add(const char *name, struct lxc_epoll_descr *descr,
static int command_mainloop_add(const char *name, struct lxc_epoll_descr *descr,
struct lxc_handler *handler)
{
int ret, fd;
......@@ -147,7 +148,7 @@ static int tty_mainloop_add(const char *name, struct lxc_epoll_descr *descr,
fd = lxc_af_unix_open(addr.sun_path, SOCK_STREAM, 0);
if (fd < 0) {
ERROR("failed to create the tty service point");
ERROR("failed to create the command service point");
return -1;
}
......@@ -157,7 +158,7 @@ static int tty_mainloop_add(const char *name, struct lxc_epoll_descr *descr,
return -1;
}
ret = lxc_mainloop_add_handler(descr, fd, ttyservice_handler,
ret = lxc_mainloop_add_handler(descr, fd, incoming_command_handler,
handler);
if (ret) {
ERROR("failed to add handler for command socket");
......@@ -175,6 +176,41 @@ static int sigchld_handler(int fd, void *data,
return 1;
}
static int command_handler(int fd, void *data,
struct lxc_epoll_descr *descr);
static int trigger_command(int fd, struct lxc_request *request,
struct lxc_handler *handler,
struct lxc_epoll_descr *descr);
static int incoming_command_handler(int fd, void *data, struct lxc_epoll_descr *descr)
{
int ret = 1, connection;
connection = accept(fd, NULL, 0);
if (connection < 0) {
SYSERROR("failed to accept connection");
return -1;
}
if (setsockopt(connection, SOL_SOCKET, SO_PASSCRED, &ret, sizeof(ret))) {
SYSERROR("failed to enable credential on socket");
goto out_close;
}
ret = lxc_mainloop_add_handler(descr, connection, command_handler, data);
if (ret) {
ERROR("failed to add handler");
goto out_close;
}
out:
return ret;
out_close:
close(connection);
goto out;
}
static void ttyinfo_remove_fd(int fd, struct lxc_tty_info *tty_info)
{
int i;
......@@ -190,43 +226,24 @@ static void ttyinfo_remove_fd(int fd, struct lxc_tty_info *tty_info)
return;
}
static void command_fd_cleanup(int fd, struct lxc_tty_info *tty_info,
static void command_fd_cleanup(int fd, struct lxc_handler *handler,
struct lxc_epoll_descr *descr)
{
ttyinfo_remove_fd(fd, tty_info);
ttyinfo_remove_fd(fd, &handler->tty_info);
lxc_mainloop_del_handler(descr, fd);
close(fd);
}
static int ttyclient_handler(int fd, void *data,
struct lxc_epoll_descr *descr)
{
struct lxc_tty_info *tty_info = data;
command_fd_cleanup(fd, tty_info, descr);
}
static int ttyservice_handler(int fd, void *data,
static int command_handler(int fd, void *data,
struct lxc_epoll_descr *descr)
{
int conn, ttynum, val = 1, ret = -1;
int ret;
struct lxc_request request;
struct lxc_handler *handler = data;
struct lxc_tty_info *tty_info = &handler->tty_info;
conn = accept(fd, NULL, 0);
if (conn < 0) {
SYSERROR("failed to accept tty client");
return -1;
}
if (setsockopt(conn, SOL_SOCKET, SO_PASSCRED, &val, sizeof(val))) {
SYSERROR("failed to enable credential on socket");
goto out_close;
}
ret = lxc_af_unix_rcv_credential(conn, &ttynum, sizeof(ttynum));
ret = lxc_af_unix_rcv_credential(fd, &request, sizeof(request));
if (ret < 0) {
SYSERROR("failed to receive data on tty socket");
SYSERROR("failed to receive data on command socket");
goto out_close;
}
......@@ -235,11 +252,32 @@ static int ttyservice_handler(int fd, void *data,
goto out_close;
}
if (ret != sizeof(ttynum)) {
if (ret != sizeof(request)) {
WARN("partial request, ignored");
goto out_close;
}
ret = trigger_command(fd, &request, handler, descr);
if (ret) {
/* this is not an error, but only a request to close fd */
ret = 0;
goto out_close;
}
out:
return ret;
out_close:
command_fd_cleanup(fd, handler, descr);
goto out;
}
static int ttyservice_handler(int fd, struct lxc_request *request,
struct lxc_handler *handler,
struct lxc_epoll_descr *descr)
{
int ttynum = request->data;
struct lxc_tty_info *tty_info = &handler->tty_info;
if (ttynum > 0) {
if (ttynum > tty_info->nbtty)
goto out_close;
......@@ -260,26 +298,37 @@ static int ttyservice_handler(int fd, void *data,
goto out_close;
out_send:
if (lxc_af_unix_send_fd(conn, tty_info->pty_info[ttynum - 1].master,
if (lxc_af_unix_send_fd(fd, tty_info->pty_info[ttynum - 1].master,
&ttynum, sizeof(ttynum)) < 0) {
ERROR("failed to send tty to client");
goto out_close;
}
if (lxc_mainloop_add_handler(descr, conn,
ttyclient_handler, tty_info)) {
ERROR("failed to add tty client handler");
goto out_close;
}
tty_info->pty_info[ttynum - 1].busy = fd;
tty_info->pty_info[ttynum - 1].busy = conn;
return 0;
ret = 0;
out:
return ret;
out_close:
close(conn);
goto out;
/* the close fd and related cleanup will be done by caller */
return 1;
}
static int trigger_command(int fd, struct lxc_request *request,
struct lxc_handler *handler,
struct lxc_epoll_descr *descr)
{
typedef int (*callback)(int, struct lxc_request *,
struct lxc_handler *,
struct lxc_epoll_descr *descr);
callback cb[LXC_COMMAND_MAX] = {
[LXC_COMMAND_TTY] = ttyservice_handler,
};
if (request->type < 0 || request->type >= LXC_COMMAND_MAX)
return -1;
return cb[request->type](fd, request, handler, descr);
}
int lxc_poll(const char *name, struct lxc_handler *handler)
......@@ -291,9 +340,8 @@ int lxc_poll(const char *name, struct lxc_handler *handler)
int nfds, ret = -1;
struct lxc_epoll_descr descr;
/* sigfd + nb tty + tty service
* if tty is enabled */
nfds = tty_info->nbtty + 1 + tty_info->nbtty ? 1 : 0;
/* nb tty + sigfd + command service */
nfds = tty_info->nbtty + 2;
if (lxc_mainloop_open(nfds, &descr)) {
ERROR("failed to create mainloop");
......@@ -305,10 +353,8 @@ int lxc_poll(const char *name, struct lxc_handler *handler)
goto out_mainloop_open;
}
if (tty_info->nbtty) {
if (tty_mainloop_add(name, &descr, handler))
goto out_mainloop_open;
}
if (command_mainloop_add(name, &descr, handler))
goto out_mainloop_open;
ret = lxc_mainloop(&descr);
......
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