/* SPDX-License-Identifier: GPL-2.0 */

/** \file server.h Common server data structures. */

/**
 * Flags for server commands and user permissions.
 *
 * For each command, zero or more of these flags are ored to define the command
 * permissions. A user is allowed to run the command if and only if all command
 * permission flags are set for the user in the server.users config file which
 * is read at server startup.
 */
enum server_command_permissions {
	NO_PERMISSION_REQUIRED = 0, /** None of the below. */
	AFS_READ = 1, /** Read-only operation on the AFS database. */
	AFS_WRITE = 2, /** Read-write operation on the AFS database. */
	VSS_READ = 4, /** Read-only operation on the virtual streaming system. */
	VSS_WRITE = 8 /** Read-write operation on the virtual streaming system. */
};

/**
 * Information stored about each user. Used during authentication.
 */
struct user {
	/** The position of this user in the list of users. */
	struct list_head node;
	/** The username. */
	char *name;
	/** The public key. */
	struct asymmetric_key *pubkey;
	/** The privileges of this user. */
	unsigned int perms;
};

const struct user *user_list_lookup(const char *name);

/** Arguments for the sender command. */
struct sender_command_data {
	/** Greater than zero indicates that a sender cmd is already queued. */
	int cmd_num;
	/** The number of the sender in question. */
	int sender_num;
	/** Used for the allow/deny/add/remove subcommands. */
	char host[MAX_HOSTLEN];
	/** Used for allow/deny. */
	int netmask;
	/** The port number for add/remove. */
	int port;
	/** Maximal slice size. */
	uint16_t max_slice_bytes;
	/** Number of data slices plus redundant slices. */
	uint8_t slices_per_group;
	/** Number of slices minus number of redundant slices. */
	uint8_t data_slices_per_group;
};

/**
 * Miscellaneous data for communication between server and command handlers.
 *
 * There is only one instance of this structure and this instance lives in
 * a shared memory area so that changes made by the command handlers are
 * visible by the server process and vice versa. Access to this area is
 * serialized by the \ref mmd_mutex.
 *
 * There are two reasons for a variable to be included here: (a) at least one
 * command handler changes its value, or (b) updates by the server must
 * propagate to the stat command handlers.
 */
struct misc_meta_data {
	/** The "old" status flags -- commands may only read them. */
	unsigned int vss_status_flags;
	/** The new status flags -- commands may set them. */
	unsigned int new_vss_status_flags;
	/** The number of data chunks sent so far. */
	long unsigned chunks_sent;
	/** Set by the jmp/ff commands to the new position in chunks. */
	long unsigned repos_request;
	/** The number of the chunk currently being sent. */
	long unsigned current_chunk;
	/** The milliseconds that have been skipped of the current audio file. */
	long offset;
	/** The time para_server started to stream. */
	struct timeval stream_start;
	/**
	 * The event counter.
	 *
	 * Commands may increase this to force a status update to be sent to
	 * all connected stat clients.
	 */
	unsigned int events;
	/** The number of audio files already sent. */
	unsigned int num_played;
	/** The number of executed commands. */
	unsigned int num_commands;
	/** The number of connections para_server received so far. */
	unsigned int num_connects;
	/** The number of connections currently active. */
	unsigned int active_connections;
	/** This gets updated by afs and contains its current mode. */
	char afs_mode_string[MAXLINE];
	/** Used by the sender command. */
	struct sender_command_data sender_cmd_data;
	/** Set by the ll command. */
	int loglevel;
	/** Describes the current audio file. */
	struct audio_file_data afd;
};

extern pid_t afs_pid;
extern struct lls_parse_result *server_lpr;
extern struct timeval announce_tv;

/** Get the parse result of an option to para_server. */
#define OPT_RESULT(_name) (lls_opt_result( \
		LSG_SERVER_PARA_SERVER_OPT_ ## _name, server_lpr))

/** How many times a server option was given. */
#define OPT_GIVEN(_name) (lls_opt_given(OPT_RESULT(_name)))

/** The (first) argument to a server option of type string. */
#define OPT_STRING_VAL(_name) (lls_string_val(0, OPT_RESULT(_name)))

/** The (first) argument to a server option of type uint32. */
#define OPT_UINT32_VAL(_name) (lls_uint32_val(0, OPT_RESULT(_name)))

/** The (first) argument to a server option of type int32. */
#define OPT_INT32_VAL(_name) (lls_int32_val(0, OPT_RESULT(_name)))

int handle_connect(int fd, int afs_fd);
void parse_config_or_die(bool reload);
bool process_is_command_handler(void);
void free_lpr(void);

void del_close_on_fork_list(int fd);
void add_close_on_fork_list(int fd);

int parse_fec_url(const char *arg, struct sender_command_data *scd);