Fix multiple error handling for UST tracing

[lttng-tools.git] / include / lttng-sessiond-comm.h

#ifndef _LTTNG_SESSIOND_COMM_H
#define _LTTNG_SESSIOND_COMM_H

/*
 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
 *                      Julien Desfossez <julien.desfossez@polymtl.ca>
 *                      Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; only version 2
 * of the License.
 * 
 * This program 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

/*
 * This header is meant for liblttng and libust internal use ONLY.
 * These declarations should NOT be considered stable API.
 */

#define _GNU_SOURCE
#include <limits.h>
#include <lttng/lttng.h>
#include <sys/socket.h>

#define LTTNG_RUNDIR                        "/var/run/lttng"
#define LTTNG_HOME_RUNDIR                   "%s/.lttng"

/* Default unix socket path */
#define DEFAULT_GLOBAL_CLIENT_UNIX_SOCK     LTTNG_RUNDIR "/client-lttng-sessiond"
#define DEFAULT_GLOBAL_APPS_UNIX_SOCK       LTTNG_RUNDIR "/apps-lttng-sessiond"
#define DEFAULT_HOME_APPS_UNIX_SOCK         LTTNG_HOME_RUNDIR "/apps-lttng-sessiond"
#define DEFAULT_HOME_CLIENT_UNIX_SOCK       LTTNG_HOME_RUNDIR "/client-lttng-sessiond"

/* Queue size of listen(2) */
#define LTTNG_SESSIOND_COMM_MAX_LISTEN 64

/*
 * Get the error code index from 0 since LTTCOMM_OK start at 1000
 */
#define LTTCOMM_ERR_INDEX(code) (code - LTTCOMM_OK)

enum lttcomm_sessiond_command {
	/* Tracer command */
	LTTNG_ADD_CONTEXT,
	LTTNG_CALIBRATE,
	LTTNG_DISABLE_CHANNEL,
	LTTNG_DISABLE_EVENT,
	LTTNG_DISABLE_ALL_EVENT,
	LTTNG_ENABLE_CHANNEL,
	LTTNG_ENABLE_EVENT,
	LTTNG_ENABLE_ALL_EVENT,
	/* Session daemon command */
	LTTNG_CREATE_SESSION,
	LTTNG_DESTROY_SESSION,
	LTTNG_LIST_CHANNELS,
	LTTNG_LIST_DOMAINS,
	LTTNG_LIST_EVENTS,
	LTTNG_LIST_SESSIONS,
	LTTNG_LIST_TRACEPOINTS,
	LTTNG_REGISTER_CONSUMER,
	LTTNG_START_TRACE,
	LTTNG_STOP_TRACE,
};

/*
 * lttcomm error code.
 */
enum lttcomm_return_code {
	LTTCOMM_OK = 1000,				/* Ok */
	LTTCOMM_ERR,					/* Unknown Error */
	LTTCOMM_UND,					/* Undefine command */
	LTTCOMM_NOT_IMPLEMENTED,        /* Command not implemented */
	LTTCOMM_UNKNOWN_DOMAIN,         /* Tracing domain not known */
	LTTCOMM_ALLOC_FAIL,				/* Trace allocation fail */
	LTTCOMM_NO_SESSION,				/* No session found */
	LTTCOMM_CREATE_FAIL,			/* Create trace fail */
	LTTCOMM_SESSION_FAIL,			/* Create session fail */
	LTTCOMM_START_FAIL,				/* Start tracing fail */
	LTTCOMM_STOP_FAIL,				/* Stop tracing fail */
	LTTCOMM_LIST_FAIL,				/* Listing apps fail */
	LTTCOMM_NO_APPS,				/* No traceable application */
	LTTCOMM_SESS_NOT_FOUND,			/* Session name not found */
	LTTCOMM_NO_TRACE,				/* No trace exist */
	LTTCOMM_FATAL,					/* Session daemon had a fatal error */
	LTTCOMM_NO_TRACEABLE,			/* Error for non traceable app */
	LTTCOMM_SELECT_SESS,			/* Must select a session */
	LTTCOMM_EXIST_SESS,				/* Session name already exist */
	LTTCOMM_NO_EVENT,				/* No event found */
	LTTCOMM_CONNECT_FAIL,           /* Unable to connect to unix socket */
	LTTCOMM_APP_NOT_FOUND,          /* App not found in traceable app list */
	LTTCOMM_EPERM,			/* Permission denied */
	LTTCOMM_KERN_NA,				/* Kernel tracer unavalable */
	LTTCOMM_KERN_EVENT_EXIST,       /* Kernel event already exists */
	LTTCOMM_KERN_SESS_FAIL,			/* Kernel create session failed */
	LTTCOMM_KERN_CHAN_FAIL,			/* Kernel create channel failed */
	LTTCOMM_KERN_CHAN_NOT_FOUND,	/* Kernel channel not found */
	LTTCOMM_KERN_CHAN_DISABLE_FAIL, /* Kernel disable channel failed */
	LTTCOMM_KERN_CHAN_ENABLE_FAIL,  /* Kernel enable channel failed */
	LTTCOMM_KERN_CONTEXT_FAIL,      /* Kernel add context failed */
	LTTCOMM_KERN_ENABLE_FAIL,		/* Kernel enable event failed */
	LTTCOMM_KERN_DISABLE_FAIL,		/* Kernel disable event failed */
	LTTCOMM_KERN_META_FAIL,			/* Kernel open metadata failed */
	LTTCOMM_KERN_START_FAIL,		/* Kernel start trace failed */
	LTTCOMM_KERN_STOP_FAIL,			/* Kernel stop trace failed */
	LTTCOMM_KERN_CONSUMER_FAIL,		/* Kernel consumer start failed */
	LTTCOMM_KERN_STREAM_FAIL,		/* Kernel create stream failed */
	LTTCOMM_KERN_DIR_FAIL,			/* Kernel trace directory creation failed */
	LTTCOMM_KERN_DIR_EXIST,			/* Kernel trace directory exist */
	LTTCOMM_KERN_NO_SESSION,		/* No kernel session found */
	LTTCOMM_KERN_LIST_FAIL,			/* Kernel listing events failed */
	LTTCOMM_UST_SESS_FAIL,			/* UST create session failed */
	LTTCOMM_UST_CHAN_EXIST,         /* UST channel already exist */
	LTTCOMM_UST_CHAN_FAIL,			/* UST create channel failed */
	LTTCOMM_UST_CHAN_NOT_FOUND,     /* UST channel not found */
	LTTCOMM_UST_CHAN_DISABLE_FAIL, /* UST disable channel failed */
	LTTCOMM_UST_CHAN_ENABLE_FAIL,  /* UST enable channel failed */
	LTTCOMM_UST_CONTEXT_FAIL,      /* UST add context failed */
	LTTCOMM_UST_ENABLE_FAIL,		/* UST enable event failed */
	LTTCOMM_UST_DISABLE_FAIL,		/* UST disable event failed */
	LTTCOMM_UST_META_FAIL,			/* UST open metadata failed */
	LTTCOMM_UST_START_FAIL,		/* UST start trace failed */
	LTTCOMM_UST_STOP_FAIL,			/* UST stop trace failed */
	LTTCOMM_UST_CONSUMER64_FAIL,		/* 64-bit UST consumer start failed */
	LTTCOMM_UST_CONSUMER32_FAIL,		/* 32-bit UST consumer start failed */
	LTTCOMM_UST_STREAM_FAIL,		/* UST create stream failed */
	LTTCOMM_UST_DIR_FAIL,			/* UST trace directory creation failed */
	LTTCOMM_UST_DIR_EXIST,			/* UST trace directory exist */
	LTTCOMM_UST_NO_SESSION,		/* No UST session found */
	LTTCOMM_UST_LIST_FAIL,			/* UST listing events failed */
	LTTCOMM_UST_EVENT_EXIST,        /* UST event exist */
	LTTCOMM_UST_EVENT_NOT_FOUND,    /* UST event not found */
	LTTCOMM_UST_CONTEXT_EXIST,      /* UST context exist */

	CONSUMERD_COMMAND_SOCK_READY,		/* when consumerd command socket ready */
	CONSUMERD_SUCCESS_RECV_FD,		/* success on receiving fds */
	CONSUMERD_ERROR_RECV_FD,		/* error on receiving fds */
	CONSUMERD_ERROR_RECV_CMD,		/* error on receiving command */
	CONSUMERD_POLL_ERROR,			/* Error in polling thread in kconsumerd */
	CONSUMERD_POLL_NVAL,			/* Poll on closed fd */
	CONSUMERD_POLL_HUP,			/* All fds have hungup */
	CONSUMERD_EXIT_SUCCESS,			/* kconsumerd exiting normally */
	CONSUMERD_EXIT_FAILURE,			/* kconsumerd exiting on error */
	CONSUMERD_OUTFD_ERROR,			/* error opening the tracefile */
	CONSUMERD_SPLICE_EBADF,			/* EBADF from splice(2) */
	CONSUMERD_SPLICE_EINVAL,		/* EINVAL from splice(2) */
	CONSUMERD_SPLICE_ENOMEM,		/* ENOMEM from splice(2) */
	CONSUMERD_SPLICE_ESPIPE,		/* ESPIPE from splice(2) */
	/* MUST be last element */
	LTTCOMM_NR,						/* Last element */
};

/*
 * Data structure received from lttng client to session daemon.
 */
struct lttcomm_session_msg {
	uint32_t cmd_type;    /* enum lttcomm_sessiond_command */
	struct lttng_session session;
	struct lttng_domain domain;
	union {
		struct {
			char channel_name[NAME_MAX];
			char name[NAME_MAX];
		} disable;
		/* Event data */
		struct {
			char channel_name[NAME_MAX];
			struct lttng_event event;
		} enable;
		/* Create channel */
		struct {
			struct lttng_channel chan;
		} channel;
		/* Context */
		struct {
			char channel_name[NAME_MAX];
			char event_name[NAME_MAX];
			struct lttng_event_context ctx;
		} context;
		/* Use by register_consumer */
		struct {
			char path[PATH_MAX];
		} reg;
		/* List */
		struct {
			char channel_name[NAME_MAX];
		} list;
		struct lttng_calibrate calibrate;
	} u;
};

/*
 * Data structure for the response from sessiond to the lttng client.
 */
struct lttcomm_lttng_msg {
	uint32_t cmd_type;   /* enum lttcomm_sessiond_command */
	uint32_t ret_code;   /* enum lttcomm_return_code */
	uint32_t pid;        /* pid_t */
	uint32_t data_size;
	/* Contains: trace_name + data */
	char payload[];
};

/*
 * lttcomm_consumer_msg is the message sent from sessiond to consumerd
 * to either add a channel, add a stream, update a stream, or stop
 * operation.
 */
struct lttcomm_consumer_msg {
	uint32_t cmd_type;	/* enum consumerd_command */
	union {
		struct {
			int channel_key;
			uint64_t max_sb_size; /* the subbuffer size for this channel */
			/* shm_fd and wait_fd are sent as ancillary data */
			uint64_t mmap_len;
		} channel;
		struct {
			int channel_key;
			int stream_key;
			/* shm_fd and wait_fd are sent as ancillary data */
			uint32_t state;    /* enum lttcomm_consumer_fd_state */
			enum lttng_event_output output; /* use splice or mmap to consume this fd */
			uint64_t mmap_len;
			uid_t uid;         /* User ID owning the session */
			gid_t gid;         /* Group ID owning the session */
			char path_name[PATH_MAX];
		} stream;
	} u;
};

#ifdef HAVE_LIBLTTNG_UST_CTL

#include <lttng/ust-abi.h>

/*
 * Data structure for the commands sent from sessiond to UST.
 */
struct lttcomm_ust_msg {
	uint32_t handle;
	uint32_t cmd;
	union {
		struct lttng_ust_channel channel;
		struct lttng_ust_stream stream;
		struct lttng_ust_event event;
		struct lttng_ust_context context;
		struct lttng_ust_tracer_version version;
	} u;
};

/*
 * Data structure for the response from UST to the session daemon.
 * cmd_type is sent back in the reply for validation.
 */
struct lttcomm_ust_reply {
	uint32_t handle;
	uint32_t cmd;
	uint32_t ret_code;	/* enum lttcomm_return_code */
	uint32_t ret_val;	/* return value */
	union {
		struct {
			uint64_t memory_map_size;
		} channel;
		struct {
			uint64_t memory_map_size;
		} stream;
		struct lttng_ust_tracer_version version;
	} u;
};

#endif /* HAVE_LIBLTTNG_UST_CTL */

extern int lttcomm_create_unix_sock(const char *pathname);
extern int lttcomm_connect_unix_sock(const char *pathname);
extern int lttcomm_accept_unix_sock(int sock);
extern int lttcomm_listen_unix_sock(int sock);
extern int lttcomm_close_unix_sock(int sock);

#define LTTCOMM_MAX_SEND_FDS	4
/* Send a message accompanied by fd(s) over a unix socket. */
extern ssize_t lttcomm_send_fds_unix_sock(int sock, int *fds, size_t nb_fd);
/* Recv a message accompanied by fd(s) from a unix socket */
extern ssize_t lttcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd);

extern ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len);
extern ssize_t lttcomm_send_unix_sock(int sock, void *buf, size_t len);

extern ssize_t lttcomm_send_creds_unix_sock(int sock, void *buf, size_t len);
extern ssize_t lttcomm_recv_creds_unix_sock(int sock, void *buf, size_t len,
		struct ucred *creds);

extern const char *lttcomm_get_readable_code(enum lttcomm_return_code code);
extern int lttcomm_setsockopt_creds_unix_sock(int sock);

#endif	/* _LTTNG_SESSIOND_COMM_H */