#include "lfs.h"
#include <assert.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/select.h>
#include <sys/wait.h>
#include <sys/ioctl.h>
#include <sys/param.h>
#include <sys/mount.h>
#include <signal.h>
#include <errno.h>
#include <netinet/tcp.h>
#include <netinet/in.h>
#include <netdb.h>
#include <syslog.h>
#include <unistd.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <linux/falloc.h>
#include <arpa/inet.h>
#include <strings.h>
#include <dirent.h>
#include <getopt.h>
#include <pwd.h>
#include <grp.h>
#include <ctype.h>
#include <glib.h>
#include "cliserv.h"
#include "nbd-debug.h"
#include "netdb-compat.h"
#include <nbdsrv.h>

Data Structures
struct	FILE_INFO
	Variables associated with an open file. More...

struct	PARAM
	Configuration file values. More...

struct	generic_conf
	Configuration file values of the "generic" section. More...

Macros
#define	MY_NAME "nbd_server"

#define	SYSCONFDIR "/etc"
	Default position of the config file. More...

#define	CFILE SYSCONFDIR "/nbd-server/config"

#define	OFFT_MAX ~((off_t)1<<(sizeof(off_t)*8-1))
	The highest value a variable of type off_t can reach. More...

#define	BUFSIZE ((1024*1024)+sizeof(struct nbd_reply))
	Size of buffer that can hold requests. More...

#define	DIFFPAGESIZE 4096
	diff file uses those chunks More...

#define	F_READONLY 1
	Per-export flags: More...

#define	F_MULTIFILE 2
	flag to tell us a file is exported using -m More...

#define	F_COPYONWRITE 4
	flag to tell us a file is exported using copyonwrite More...

#define	F_AUTOREADONLY 8
	flag to tell us a file is set to autoreadonly More...

#define	F_SPARSE 16
	flag to tell us copyronwrite should use a sparse file More...

#define	F_SDP 32
	flag to tell us the export should be done using the Socket Direct Protocol for RDMA More...

#define	F_SYNC 64
	Whether to fsync() after a write. More...

#define	F_FLUSH 128
	Whether server wants FLUSH to be sent by the client. More...

#define	F_FUA 256
	Whether server wants FUA to be sent by the client. More...

#define	F_ROTATIONAL 512
	Whether server wants the client to implement the elevator algorithm. More...

#define	F_TEMPORARY 1024
	Whether the backing file is temporary and should be created then unlinked. More...

#define	F_TRIM 2048
	Whether server wants TRIM (discard) to be sent by the client. More...

#define	F_FIXED 4096
	Client supports fixed new-style protocol (and can thus send us extra options. More...

#define	F_OLDSTYLE 1
	Global flags: More...

#define	F_LIST 2
	Allow clients to list the exports on a server. More...

#define	NEG_INIT (1 << 0)

#define	NEG_OLD (1 << 1)

#define	NEG_MODERN (1 << 2)

#define	SEND(net, reply)
	sending macro. More...

#define	ERROR(client, reply, errcode) { reply.error = htonl(errcode); SEND(client->net,reply); reply.error = 0; }
	error macro. More...

Enumerations
enum	PARAM_TYPE { PARAM_INT, PARAM_INT64, PARAM_STRING, PARAM_BOOL }
	Type of configuration file values. More...

Functions
static const char *	getcommandname (uint64_t command)
	Translate a command name into human readable form. More...

static void	readit (int f, void *buf, size_t len)
	Read data from a file descriptor into a buffer. More...

static void	consume (int f, void *buf, size_t len, size_t bufsiz)
	Consume data from an FD that we don't want. More...

static void	writeit (int f, void *buf, size_t len)
	Write data from a buffer into a filedescriptor. More...

void	usage ()
	Print out a message about how to use nbd-server. More...

void	dump_section (SERVER serve, gchar section_header)

SERVER *	cmdline (int argc, char *argv[])
	Parse the command line. More...

GArray *	parse_cfile (gchar f, struct generic_conf const genconf, GError **e)
	Parse the config file. More...

GArray *	do_cfile_dir (gchar dir, GError *e)
	Parse config file snippets in a directory. More...

void	sigchld_handler (int s)
	Signal handler for SIGCHLD. More...

void	killchild (gpointer key, gpointer value, gpointer user_data)
	Kill a child. More...

void	sigterm_handler (int s)
	Handle SIGTERM and dispatch it to our children. More...

static void	sighup_handler (const int s G_GNUC_UNUSED)
	Handle SIGHUP by setting atomically a flag which will be evaluated in the main loop of the root server process. More...

int	get_filepos (GArray export, off_t a, int fhandle, off_t foffset, size_t maxbytes)
	Get the file handle and offset, given an export offset. More...

void	myseek (int handle, off_t a)
	seek to a position in a file, with error handling. More...

ssize_t	rawexpwrite (off_t a, char buf, size_t len, CLIENT client, int fua)
	Write an amount of bytes at a given offset to the right file. More...

int	rawexpwrite_fully (off_t a, char buf, size_t len, CLIENT client, int fua)
	Call rawexpwrite repeatedly until all data has been written. More...

ssize_t	rawexpread (off_t a, char buf, size_t len, CLIENT client)
	Read an amount of bytes at a given offset from the right file. More...

int	rawexpread_fully (off_t a, char buf, size_t len, CLIENT client)
	Call rawexpread repeatedly until all data has been read. More...

int	expread (off_t a, char buf, size_t len, CLIENT client)
	Read an amount of bytes at a given offset from the right file. More...

int	expwrite (off_t a, char buf, size_t len, CLIENT client, int fua)
	Write an amount of bytes at a given offset to the right file. More...

int	expflush (CLIENT *client)
	Flush data to a client. More...

int	exptrim (struct nbd_request req, CLIENT client)

static void	send_reply (uint32_t opt, int net, uint32_t reply_type, size_t datasize, void *data)

static CLIENT *	handle_export_name (uint32_t opt, int net, GArray *servers, uint32_t cflags)

static void	handle_list (uint32_t opt, int net, GArray *servers, uint32_t cflags)

CLIENT *	negotiate (int net, CLIENT client, GArray servers, int phase)
	Do the initial negotiation. More...

int	mainloop (CLIENT *client)
	Serve a file to a single client. More...

void	setupexport (CLIENT *client)
	Set up client export array, which is an array of FILE_INFO. More...

int	copyonwrite_prepare (CLIENT *client)

int	do_run (gchar command, gchar file)
	Run a command. More...

void	serveconnection (CLIENT *client)
	Serve a connection. More...

int	set_peername (int net, CLIENT *client)
	Find the name of the file we have to serve. More...

void	destroy_pid_t (gpointer data)
	Destroy a pid_t*. More...

static pid_t	spawn_child ()

static int	socket_accept (const int sock)

static void	handle_modern_connection (GArray *const servers, const int sock)

static void	handle_oldstyle_connection (GArray const servers, SERVER const serve)

static int	get_index_by_servename (const gchar const servename, const GArray const servers)
	Return the index of the server whose servename matches the given name. More...

int	setup_serve (SERVER const serve, GError *const gerror)
	Connect a server's socket. More...

static int	append_new_servers (GArray const servers, GError *const gerror)
	Parse configuration files and add servers to the array if they don't already exist there. More...

void	serveloop (GArray *servers)
	Loop through the available servers, and serve them. More...

int	dosockopts (const int socket, GError **const gerror)
	Set server socket options. More...

int	open_modern (const gchar const addr, const gchar const port, GError **const gerror)

void	setup_servers (GArray const servers, const gchar const modernaddr, const gchar *const modernport)
	Connect our servers. More...

void	daemonize (SERVER *serve)
	Go daemon (unless we specified at compile time that we didn't want this) More...

void	dousers (const gchar const username, const gchar const groupname)
	Set up user-ID and/or group-ID. More...

void	glib_message_syslog_redirect (const gchar log_domain, GLogLevelFlags log_level, const gchar message, gpointer user_data)

int	main (int argc, char *argv[])
	Main entry point... More...

Variables
gchar *	config_file_pos
	Where our config file actually is. More...

int	glob_flags =0
	global flags More...

int	dontfork = 0

GHashTable *	children

char	pidfname [256]
	name of our PID file More...

char	pidftemplate [256]
	template to be used for the filename of the PID file More...

char	default_authname [] = SYSCONFDIR "/nbd-server/allow"
	default name of allow file More...

static volatile sig_atomic_t	is_sighup_caught
	Flag set by SIGHUP handler to mark a reconfiguration request. More...

GArray *	modernsocks
	Sockets for the modern handler. More...

bool	logged_oversized =false
	whether we logged oversized requests already More...

Macro Definition Documentation

#define BUFSIZE ((1024*1024)+sizeof(struct nbd_reply))

Size of buffer that can hold requests.

Definition at line 132 of file nbd-server.c.

Referenced by mainloop().

#define CFILE SYSCONFDIR "/nbd-server/config"

Definition at line 116 of file nbd-server.c.

Referenced by main(), and usage().

#define DIFFPAGESIZE 4096

diff file uses those chunks

Definition at line 133 of file nbd-server.c.

Referenced by copyonwrite_prepare(), expread(), and expwrite().

#define ERROR	(	client,
		reply,
		errcode
	)	{ reply.error = htonl(errcode); SEND(client->net,reply); reply.error = 0; }

error macro.

Definition at line 1428 of file nbd-server.c.

Referenced by mainloop().

#define F_AUTOREADONLY 8

flag to tell us a file is set to autoreadonly

Definition at line 141 of file nbd-server.c.

Referenced by mainloop(), and setupexport().

#define F_COPYONWRITE 4

flag to tell us a file is exported using copyonwrite

Definition at line 138 of file nbd-server.c.

Referenced by cmdline(), dump_section(), expflush(), expread(), expwrite(), mainloop(), parse_cfile(), serveconnection(), and setupexport().

#define F_FIXED 4096

Client supports fixed new-style protocol (and can thus send us extra options.

Definition at line 150 of file nbd-server.c.

#define F_FLUSH 128

Whether server wants FLUSH to be sent by the client.

Definition at line 145 of file nbd-server.c.

Referenced by negotiate(), and parse_cfile().

#define F_FUA 256

Whether server wants FUA to be sent by the client.

Definition at line 146 of file nbd-server.c.

Referenced by negotiate(), and parse_cfile().

#define F_LIST 2

Allow clients to list the exports on a server.

Definition at line 154 of file nbd-server.c.

Referenced by handle_list(), and parse_cfile().

#define F_MULTIFILE 2

flag to tell us a file is exported using -m

Definition at line 137 of file nbd-server.c.

Referenced by cmdline(), dump_section(), parse_cfile(), and setupexport().

#define F_OLDSTYLE 1

Global flags:

Allow oldstyle (port-based) exports

Definition at line 153 of file nbd-server.c.

Referenced by cmdline(), parse_cfile(), and setup_serve().

#define F_READONLY 1

Per-export flags:

flag to tell us a file is readonly

Definition at line 136 of file nbd-server.c.

Referenced by cmdline(), dump_section(), mainloop(), negotiate(), parse_cfile(), and setupexport().

#define F_ROTATIONAL 512

Whether server wants the client to implement the elevator algorithm.

Definition at line 147 of file nbd-server.c.

Referenced by negotiate(), and parse_cfile().

#define F_SDP 32

flag to tell us the export should be done using the Socket Direct Protocol for RDMA

Definition at line 143 of file nbd-server.c.

Referenced by parse_cfile(), and setup_serve().

#define F_SPARSE 16

flag to tell us copyronwrite should use a sparse file

Definition at line 142 of file nbd-server.c.

Referenced by expwrite(), and parse_cfile().

#define F_SYNC 64

Whether to fsync() after a write.

Definition at line 144 of file nbd-server.c.

Referenced by expwrite(), parse_cfile(), and rawexpwrite().

#define F_TEMPORARY 1024

Whether the backing file is temporary and should be created then unlinked.

Definition at line 148 of file nbd-server.c.

Referenced by parse_cfile(), and setupexport().

#define F_TRIM 2048

Whether server wants TRIM (discard) to be sent by the client.

Definition at line 149 of file nbd-server.c.

Referenced by negotiate(), and parse_cfile().

#define MY_NAME "nbd_server"

Definition at line 103 of file nbd-server.c.

#define NEG_INIT (1 << 0)

Definition at line 160 of file nbd-server.c.

Referenced by handle_modern_connection(), mainloop(), and negotiate().

#define NEG_MODERN (1 << 2)

Definition at line 162 of file nbd-server.c.

Referenced by handle_modern_connection(), mainloop(), and negotiate().

#define NEG_OLD (1 << 1)

Definition at line 161 of file nbd-server.c.

Referenced by mainloop(), and negotiate().

#define OFFT_MAX ~((off_t)1<<(sizeof(off_t)*8-1))

The highest value a variable of type off_t can reach.

This is a signed integer, so set all bits except for the leftmost one.

Definition at line 131 of file nbd-server.c.

Referenced by handle_export_name(), handle_oldstyle_connection(), and main().

#define SEND	(	net,
		reply
	)

Value:

{ writeit( net, &reply, sizeof( reply )); \
        if (client->transactionlogfd != -1) \
		writeit(client->transactionlogfd, &reply, sizeof(reply)); }

sending macro.

Definition at line 1424 of file nbd-server.c.

Referenced by mainloop().

#define SYSCONFDIR "/etc"

Default position of the config file.

Definition at line 114 of file nbd-server.c.

Enumeration Type Documentation

enum PARAM_TYPE

Type of configuration file values.

Enumerator
PARAM_INT	This parameter is an integer.
PARAM_INT64	This parameter is an integer.
PARAM_STRING	This parameter is a string.
PARAM_BOOL	This parameter is a boolean.

Definition at line 193 of file nbd-server.c.

Function Documentation

static int append_new_servers	(	GArray *const	servers,
		GError **const	gerror
	)

static

Parse configuration files and add servers to the array if they don't already exist there.

The existence is tested by comparing servenames. A server is appended to the array only if its servename is unique among all other servers.

Parameters

servers an array of servers

Returns: the number of new servers appended to the array, or -1 in case of an error

Definition at line 2172 of file nbd-server.c.

References append_serve(), config_file_pos, get_index_by_servename(), parse_cfile(), SERVER::servename, and setup_serve().

Referenced by serveloop().

SERVER* cmdline	(	int	argc,
		char *	argv[]
	)

Parse the command line.

Parameters

argc	the argc argument to main()
argv	the argv argument to main()

Definition at line 360 of file nbd-server.c.

References SERVER::authname, config_file_pos, default_authname, dontfork, dump_section(), SERVER::expected_size, SERVER::exportname, F_COPYONWRITE, F_MULTIFILE, F_OLDSTYLE, F_READONLY, SERVER::flags, glob_flags, SERVER::listenaddr, SERVER::max_connections, pidftemplate, SERVER::port, usage(), VIRT_IPLIT, and SERVER::virtstyle.

Referenced by main().

static void consume	(	int	f,
		void *	buf,
		size_t	len,
		size_t	bufsiz
	)

inlinestatic

Consume data from an FD that we don't want.

Parameters

f	a file descriptor
buf	a buffer
len	the number of bytes to consume
bufsiz	the size of the buffer

Definition at line 281 of file nbd-server.c.

References readit().

Referenced by mainloop().

int copyonwrite_prepare ( CLIENT * client )

Definition at line 1703 of file nbd-server.c.

References CLIENT::clientname, CLIENT::difffile, CLIENT::difffilename, DIFFPAGESIZE, CLIENT::difmap, err(), CLIENT::exportname, CLIENT::exportsize, and msg.

Referenced by serveconnection().

void daemonize ( SERVER * serve )

Go daemon (unless we specified at compile time that we didn't want this)

Parameters

serve the first server of our configuration. If its port is zero, then do not daemonize, because we're doing inetd then. This parameter is only used to create a PID file of the form /var/run/nbd-server.<port>.pid; it's not modified in any way.

Definition at line 2602 of file nbd-server.c.

References err(), pidfname, pidftemplate, and SERVER::port.

Referenced by main().

void destroy_pid_t ( gpointer data )

Destroy a pid_t*.

Parameters

data	a pointer to pid_t which should be freed

Definition at line 1880 of file nbd-server.c.

Referenced by setup_servers().

GArray* do_cfile_dir	(	gchar *	dir,
		GError **	e
	)

Parse config file snippets in a directory.

Uses readdir() and friends to find files and open them, then passes them on to parse_cfile with have_global set false

Definition at line 505 of file nbd-server.c.

References NBDS_ERR, NBDS_ERR_CFILE_DIR_UNKNOWN, NBDS_ERR_CFILE_READDIR_ERR, and parse_cfile().

Referenced by parse_cfile().

int do_run	(	gchar *	command,
		gchar *	file
	)

Run a command.

This is used for the prerun'' andpostrun'' config file options

Parameters

command	the command to be ran. Read from the config file
file	the file name we're about to export

Definition at line 1727 of file nbd-server.c.

Referenced by serveconnection().

int dosockopts	(	const int	socket,
		GError **const	gerror
	)

Set server socket options.

Parameters

socket	a socket descriptor of the server
gerror	a pointer to an error object pointer used for reporting errors. On error, if gerror is not NULL, *gerror is set and -1 is returned.

Returns: 0 on success, -1 on error

Definition at line 2306 of file nbd-server.c.

References NBDS_ERR, NBDS_ERR_SO_KEEPALIVE, NBDS_ERR_SO_LINGER, and NBDS_ERR_SO_REUSEADDR.

Referenced by open_modern(), and setup_serve().

void dousers	(	const gchar *const	username,
		const gchar *const	groupname
	)

Set up user-ID and/or group-ID.

Definition at line 2640 of file nbd-server.c.

References err().

Referenced by main().

void dump_section	(	SERVER *	serve,
		gchar *	section_header
	)

Definition at line 331 of file nbd-server.c.

References SERVER::authname, SERVER::expected_size, SERVER::exportname, F_COPYONWRITE, F_MULTIFILE, F_READONLY, SERVER::flags, SERVER::listenaddr, and SERVER::port.

Referenced by cmdline().

int expflush ( CLIENT * client )

Flush data to a client.

Parameters

client The client we're going to write for.

Returns: 0 on success, nonzero on failure

Definition at line 1179 of file nbd-server.c.

References CLIENT::difffile, CLIENT::export, F_COPYONWRITE, FILE_INFO::fhandle, SERVER::flags, and CLIENT::server.

Referenced by mainloop().

int expread	(	off_t	a,
		char *	buf,
		size_t	len,
		CLIENT *	client
	)

Read an amount of bytes at a given offset from the right file.

This abstracts the read-side of the copyonwrite stuff, and calls rawexpread() with the right parameters to do the actual work.

Parameters

a	The offset where the read should start
buf	A buffer to read into
len	The size of buf
client	The client we're going to read for

Returns: 0 on success, nonzero on failure

Definition at line 1079 of file nbd-server.c.

References DEBUG, CLIENT::difffile, DIFFPAGESIZE, CLIENT::difmap, F_COPYONWRITE, SERVER::flags, myseek(), rawexpread_fully(), and CLIENT::server.

Referenced by mainloop().

int exptrim	(	struct nbd_request *	req,
		CLIENT *	client
	)

Definition at line 1199 of file nbd-server.c.

References DEBUG, CLIENT::export, FILE_INFO::fhandle, nbd_request::from, nbd_request::len, and FILE_INFO::startoff.

Referenced by mainloop().

int expwrite	(	off_t	a,
		char *	buf,
		size_t	len,
		CLIENT *	client,
		int	fua
	)

Write an amount of bytes at a given offset to the right file.

This abstracts the write-side of the copyonwrite option, and calls rawexpwrite() with the right parameters to do the actual work.

Parameters

a	The offset where the write should start
buf	The buffer to write from
len	The length of buf
client	The client we're going to write for.
fua	Flag to indicate 'Force Unit Access'

Returns: 0 on success, nonzero on failure

Definition at line 1121 of file nbd-server.c.

References DEBUG, CLIENT::difffile, CLIENT::difffilelen, DIFFPAGESIZE, CLIENT::difmap, F_COPYONWRITE, F_SPARSE, F_SYNC, fdatasync, SERVER::flags, myseek(), rawexpread_fully(), rawexpwrite_fully(), and CLIENT::server.

Referenced by mainloop().

int get_filepos	(	GArray *	export,
		off_t	a,
		int *	fhandle,
		off_t *	foffset,
		size_t *	maxbytes
	)

Get the file handle and offset, given an export offset.

Parameters

export	An array of export files
a	The offset to get corresponding file/offset for
fhandle	[out] File descriptor
foffset	[out] Offset into fhandle
maxbytes	[out] Tells how many bytes can be read/written from fhandle starting at foffset (0 if there is no limit)

Returns: 0 on success, -1 on failure

Definition at line 886 of file nbd-server.c.

References FILE_INFO::fhandle, and FILE_INFO::startoff.

Referenced by rawexpread(), and rawexpwrite().

static int get_index_by_servename	(	const gchar *const	servename,
		const GArray *const	servers
	)

static

Return the index of the server whose servename matches the given name.

Parameters

servename	a string to match
servers	an array of servers

Returns: the first index of the server whose servename matches the given name or -1 if one cannot be found

Definition at line 2146 of file nbd-server.c.

References SERVER::servename.

Referenced by append_new_servers().

static const char* getcommandname ( uint64_t command )

inlinestatic

Translate a command name into human readable form.

Parameters

command The command number (after applying NBD_CMD_MASK_COMMAND)

Returns: pointer to the command name

Definition at line 234 of file nbd-server.c.

References NBD_CMD_DISC, NBD_CMD_FLUSH, NBD_CMD_READ, NBD_CMD_TRIM, and NBD_CMD_WRITE.

Referenced by mainloop().

void glib_message_syslog_redirect	(	const gchar *	log_domain,
		GLogLevelFlags	log_level,
		const gchar *	message,
		gpointer	user_data
	)

Definition at line 2667 of file nbd-server.c.

Referenced by main().

static CLIENT* handle_export_name	(	uint32_t	opt,
		int	net,
		GArray *	servers,
		uint32_t	cflags
	)

static

Definition at line 1243 of file nbd-server.c.

References CLIENT::clientfeats, err(), CLIENT::exportsize, CLIENT::modern, CLIENT::net, OFFT_MAX, SERVER::servename, CLIENT::server, and CLIENT::transactionlogfd.

Referenced by negotiate().

static void handle_list	(	uint32_t	opt,
		int	net,
		GArray *	servers,
		uint32_t	cflags
	)

static

Definition at line 1279 of file nbd-server.c.

References err(), err_nonfatal(), F_LIST, glob_flags, len, NBD_REP_ACK, NBD_REP_ERR_INVALID, NBD_REP_ERR_POLICY, NBD_REP_SERVER, send_reply(), and SERVER::servename.

Referenced by negotiate().

static void handle_modern_connection	(	GArray *const	servers,
		const int	sock
	)

static

Definition at line 1933 of file nbd-server.c.

References authorized_client(), children, CLIENT::clientname, dontfork, SERVER::max_connections, modernsocks, msg, NEG_INIT, NEG_MODERN, negotiate(), serveconnection(), CLIENT::server, set_peername(), SERVER::socket, socket_accept(), and spawn_child().

Referenced by serveloop().

static void handle_oldstyle_connection	(	GArray *const	servers,
		SERVER *const	serve
	)

static

Definition at line 2040 of file nbd-server.c.

References authorized_client(), children, dontfork, err(), CLIENT::exportsize, SERVER::max_connections, modernsocks, msg, CLIENT::net, OFFT_MAX, serveconnection(), CLIENT::server, set_peername(), SERVER::socket, socket_accept(), and CLIENT::transactionlogfd.

Referenced by serveloop().

void killchild	(	gpointer	key,
		gpointer	value,
		gpointer	user_data
	)

Kill a child.

Called from sigterm_handler::g_hash_table_foreach.

Parameters

key	the key
value	the value corresponding to the above key
user_data	a pointer which we always set to 1, so that we know what will happen next.

Definition at line 844 of file nbd-server.c.

Referenced by sigterm_handler().

int main	(	int	argc,
		char *	argv[]
	)

Main entry point...

Definition at line 2701 of file nbd-server.c.

References append_serve(), CFILE, cmdline(), config_file_pos, daemonize(), dontfork, dousers(), err(), CLIENT::exportsize, generic_conf::flags, glib_message_syslog_redirect(), glob_flags, generic_conf::group, logging(), generic_conf::modernaddr, generic_conf::modernport, modernsocks, NBDS_ERR, NBDS_ERR_CFILE_NOTFOUND, CLIENT::net, OFFT_MAX, parse_cfile(), pidftemplate, SERVER::port, serveconnection(), serveloop(), CLIENT::server, set_peername(), setup_servers(), SERVER::socket_family, and generic_conf::user.

int mainloop ( CLIENT * client )

Serve a file to a single client.

Todo:: This beast needs to be split up in many tiny little manageable pieces. Preferably with a chainsaw.

Parameters

client The client we're going to serve to.

Returns: when the client disconnects

Definition at line 1438 of file nbd-server.c.

References BUFSIZE, consume(), DEBUG, CLIENT::difffile, CLIENT::difffilename, CLIENT::difmap, err(), nbd_reply::error, ERROR, expflush(), CLIENT::exportsize, expread(), exptrim(), expwrite(), F_AUTOREADONLY, F_COPYONWRITE, F_READONLY, SERVER::flags, nbd_request::from, getcommandname(), nbd_request::handle, nbd_reply::handle, len, nbd_request::len, logged_oversized, nbd_request::magic, nbd_reply::magic, CLIENT::modern, msg, NBD_CMD_DISC, NBD_CMD_FLAG_FUA, NBD_CMD_FLUSH, NBD_CMD_MASK_COMMAND, NBD_CMD_READ, NBD_CMD_TRIM, NBD_CMD_WRITE, NBD_REPLY_MAGIC, NBD_REQUEST_MAGIC, NEG_INIT, NEG_MODERN, NEG_OLD, negotiate(), CLIENT::net, ntohll(), readit(), SEND, CLIENT::server, CLIENT::transactionlogfd, nbd_request::type, and writeit().

Referenced by serveconnection().

void myseek	(	int	handle,
		off_t	a
	)

seek to a position in a file, with error handling.

Parameters

handle	a filedescriptor
a	position to seek to

Todo:: get rid of this.

Definition at line 929 of file nbd-server.c.

References err().

Referenced by expread(), expwrite(), rawexpread(), and rawexpwrite().

CLIENT* negotiate	(	int	net,
		CLIENT *	client,
		GArray *	servers,
		int	phase
	)

Do the initial negotiation.

Parameters

client The client we're negotiating with.

Definition at line 1311 of file nbd-server.c.

References cliserv_magic, err(), err_nonfatal(), CLIENT::exportsize, F_FLUSH, F_FUA, F_READONLY, F_ROTATIONAL, F_TRIM, SERVER::flags, handle_export_name(), handle_list(), htonll, INIT_PASSWD, magic, NBD_FLAG_FIXED_NEWSTYLE, NBD_FLAG_HAS_FLAGS, NBD_FLAG_READ_ONLY, NBD_FLAG_ROTATIONAL, NBD_FLAG_SEND_FLUSH, NBD_FLAG_SEND_FUA, NBD_FLAG_SEND_TRIM, NBD_OPT_ABORT, NBD_OPT_EXPORT_NAME, NBD_OPT_LIST, NBD_REP_ERR_UNSUP, NEG_INIT, NEG_MODERN, NEG_OLD, CLIENT::net, ntohll(), opts_magic, send_reply(), and CLIENT::server.

int open_modern	(	const gchar *const	addr,
		const gchar *const	port,
		GError **const	gerror
	)

Definition at line 2450 of file nbd-server.c.

References dosockopts(), modernsocks, NBD_DEFAULT_PORT, NBDS_ERR, NBDS_ERR_BIND, NBDS_ERR_GAI, and NBDS_ERR_SOCKET.

Referenced by setup_servers().

GArray * parse_cfile	(	gchar *	f,
		struct generic_conf *const	genconf,
		GError **	e
	)

Parse the config file.

Parameters

f	the name of the config file
genconf	a pointer to generic configuration which will get updated with parsed values. If NULL, then parsed generic configuration values are safely and silently discarded.
e	a GError. Error code can be any of the following: NBDS_ERR_CFILE_NOTFOUND, NBDS_ERR_CFILE_MISSING_GENERIC, NBDS_ERR_CFILE_VALUE_INVALID, NBDS_ERR_CFILE_VALUE_UNSUPPORTED or NBDS_ERR_CFILE_NO_EXPORTS.

See Also: NBDS_ERRS.

Returns: a Array of SERVER* pointers, If the config file is empty or does not exist, returns an empty GHashTable; if the config file contains an error, returns NULL, and e is set appropriately

Definition at line 583 of file nbd-server.c.

References append_serve(), SERVER::authname, SERVER::cidrlen, do_cfile_dir(), err(), SERVER::expected_size, SERVER::exportname, F_COPYONWRITE, F_FLUSH, F_FUA, F_LIST, F_MULTIFILE, F_OLDSTYLE, F_READONLY, F_ROTATIONAL, F_SDP, F_SPARSE, F_SYNC, F_TEMPORARY, F_TRIM, SERVER::flags, generic_conf::flags, glob_flags, generic_conf::group, SERVER::listenaddr, SERVER::max_connections, generic_conf::modernaddr, generic_conf::modernport, NBDS_ERR, NBDS_ERR_CFILE_MISSING_GENERIC, NBDS_ERR_CFILE_NO_EXPORTS, NBDS_ERR_CFILE_NOTFOUND, NBDS_ERR_CFILE_VALUE_INVALID, NBDS_ERR_CFILE_VALUE_UNSUPPORTED, PARAM_BOOL, PARAM_INT, PARAM_INT64, PARAM_OFFT, PARAM_STRING, SERVER::port, SERVER::postrun, SERVER::prerun, PARAM::required, SERVER::servename, SERVER::socket_family, SERVER::transactionlog, generic_conf::user, VIRT_CIDR, VIRT_IPHASH, VIRT_IPLIT, VIRT_NONE, and SERVER::virtstyle.

Referenced by append_new_servers(), do_cfile_dir(), and main().

ssize_t rawexpread	(	off_t	a,
		char *	buf,
		size_t	len,
		CLIENT *	client
	)

Read an amount of bytes at a given offset from the right file.

This abstracts the read-side of the multiple files option.

Parameters

a	The offset where the read should start
buf	A buffer to read into
len	The size of buf
client	The client we're serving for

Returns: The number of bytes actually read, or -1 in case of an error.

Definition at line 1038 of file nbd-server.c.

References DEBUG, CLIENT::export, get_filepos(), and myseek().

Referenced by rawexpread_fully().

int rawexpread_fully	(	off_t	a,
		char *	buf,
		size_t	len,
		CLIENT *	client
	)

Call rawexpread repeatedly until all data has been read.

Returns: 0 on success, nonzero on failure

Definition at line 1058 of file nbd-server.c.

References rawexpread().

Referenced by expread(), and expwrite().

ssize_t rawexpwrite	(	off_t	a,
		char *	buf,
		size_t	len,
		CLIENT *	client,
		int	fua
	)

Write an amount of bytes at a given offset to the right file.

This abstracts the write-side of the multiple file option.

Parameters

a	The offset where the write should start
buf	The buffer to write from
len	The length of buf
client	The client we're serving for
fua	Flag to indicate 'Force Unit Access'

Returns: The number of bytes actually written, or -1 in case of an error

Definition at line 946 of file nbd-server.c.

References DEBUG, CLIENT::export, F_SYNC, fdatasync, SERVER::flags, get_filepos(), myseek(), and CLIENT::server.

Referenced by rawexpwrite_fully().

int rawexpwrite_fully	(	off_t	a,
		char *	buf,
		size_t	len,
		CLIENT *	client,
		int	fua
	)

Call rawexpwrite repeatedly until all data has been written.

Parameters

a	The offset where the write should start
buf	The buffer to write from
len	The length of buf
client	The client we're serving for
fua	Flag to indicate 'Force Unit Access'

Returns: 0 on success, nonzero on failure

Definition at line 1016 of file nbd-server.c.

References rawexpwrite().

Referenced by expwrite().

static void readit	(	int	f,
		void *	buf,
		size_t	len
	)

inlinestatic

Read data from a file descriptor into a buffer.

Parameters

f	a file descriptor
buf	a buffer
len	the number of bytes to be read

Definition at line 258 of file nbd-server.c.

References DEBUG, and err().

Referenced by consume(), and mainloop().

static void send_reply	(	uint32_t	opt,
		int	net,
		uint32_t	reply_type,
		size_t	datasize,
		void *	data
	)

static

Definition at line 1224 of file nbd-server.c.

References htonll, and magic.

Referenced by handle_list(), and negotiate().

void serveconnection ( CLIENT * client )

Serve a connection.

Todo:: allow for multithreading, perhaps use libevent. Not just yet, though; follow the road map.

Parameters

client a connected client

Definition at line 1747 of file nbd-server.c.

References copyonwrite_prepare(), do_run(), CLIENT::exportname, F_COPYONWRITE, SERVER::flags, mainloop(), CLIENT::net, SERVER::postrun, SERVER::prerun, CLIENT::server, setmysockopt(), setupexport(), SERVER::transactionlog, and CLIENT::transactionlogfd.

Referenced by handle_modern_connection(), handle_oldstyle_connection(), and main().

void serveloop ( GArray * servers )

Loop through the available servers, and serve them.

Never returns.

Definition at line 2206 of file nbd-server.c.

References append_new_servers(), DEBUG, handle_modern_connection(), handle_oldstyle_connection(), is_sighup_caught, len, modernsocks, msg, SERVER::servename, and SERVER::socket.

Referenced by main().

int set_peername	(	int	net,
		CLIENT *	client
	)

Find the name of the file we have to serve.

This will use g_strdup_printf to put the IP address of the client inside a filename containing "%s" (in the form as specified by the "virtstyle" option). That name is then written to client->exportname.

Parameters

net	A socket connected to an nbd client
client	information about the client. The IP address in human-readable format will be written to a new char* buffer, the address of which will be stored in client->clientname.

Returns: : 0 - OK, -1 - failed.

Definition at line 1790 of file nbd-server.c.

References SERVER::cidrlen, CLIENT::clientaddr, CLIENT::clientname, SERVER::exportname, CLIENT::exportname, getmaskbyte(), msg, CLIENT::server, VIRT_CIDR, VIRT_IPHASH, VIRT_IPLIT, VIRT_NONE, and SERVER::virtstyle.

Referenced by handle_modern_connection(), handle_oldstyle_connection(), and main().

int setup_serve	(	SERVER *const	serve,
		GError **const	gerror
	)

Connect a server's socket.

Parameters

serve the server we want to connect.

Definition at line 2344 of file nbd-server.c.

References AI_NUMERICSERV, DEBUG, dosockopts(), F_OLDSTYLE, F_SDP, SERVER::flags, glob_flags, SERVER::listenaddr, NBDS_ERR, NBDS_ERR_BIND, NBDS_ERR_GAI, NBDS_ERR_SOCKET, NBDS_ERR_SYS, SERVER::port, SERVER::servename, SERVER::socket, and SERVER::socket_family.

Referenced by append_new_servers(), and setup_servers().

void setup_servers	(	GArray *const	servers,
		const gchar *const	modernaddr,
		const gchar *const	modernport
	)

Connect our servers.

Definition at line 2542 of file nbd-server.c.

References children, destroy_pid_t(), err(), msg, open_modern(), setup_serve(), sigchld_handler(), sighup_handler(), and sigterm_handler().

Referenced by main().

void setupexport ( CLIENT * client )

Set up client export array, which is an array of FILE_INFO.

Also, split a single exportfile into multiple ones, if that was asked.

Parameters

client information on the client which we want to setup export for

Definition at line 1601 of file nbd-server.c.

References DEBUG, err(), SERVER::expected_size, CLIENT::export, CLIENT::exportname, CLIENT::exportsize, F_AUTOREADONLY, F_COPYONWRITE, F_MULTIFILE, F_READONLY, F_TEMPORARY, FILE_INFO::fhandle, SERVER::flags, msg, CLIENT::server, size_autodetect(), and FILE_INFO::startoff.

Referenced by serveconnection().

void sigchld_handler ( int s )

Signal handler for SIGCHLD.

Parameters

s	the signal we're handling (must be SIGCHLD, or something is severely wrong)

Definition at line 817 of file nbd-server.c.

References children, DEBUG, and msg.

Referenced by setup_servers().

static void sighup_handler ( const int s G_GNUC_UNUSED )

static

Handle SIGHUP by setting atomically a flag which will be evaluated in the main loop of the root server process.

This allows us to separate the signal catching from th actual task triggered by SIGHUP and hence processing in the interrupt context is kept as minimial as possible.

Parameters

s	the signal we're handling (must be SIGHUP, or something is severely wrong).

Definition at line 871 of file nbd-server.c.

References is_sighup_caught.

Referenced by setup_servers().

void sigterm_handler ( int s )

Handle SIGTERM and dispatch it to our children.

Parameters

s	the signal we're handling (must be SIGTERM, or something is severely wrong).

Definition at line 855 of file nbd-server.c.

References children, killchild(), and pidfname.

Referenced by setup_servers().

static int socket_accept ( const int sock )

static

Definition at line 1918 of file nbd-server.c.

References err_nonfatal().

Referenced by handle_modern_connection(), and handle_oldstyle_connection().

static pid_t spawn_child ( )

static

Definition at line 1885 of file nbd-server.c.

References children, and msg.

Referenced by handle_modern_connection().

void usage ( )

Print out a message about how to use nbd-server.

Split out to a separate function so that we can call it from multiple places

Definition at line 312 of file nbd-server.c.

References CFILE, and VERSION.

static void writeit	(	int	f,
		void *	buf,
		size_t	len
	)

inlinestatic

Write data from a buffer into a filedescriptor.

Parameters

f	a file descriptor
buf	a buffer containing data
len	the number of bytes to be written

Definition at line 297 of file nbd-server.c.

References DEBUG, and err().

Referenced by mainloop().

Variable Documentation

GHashTable* children

Definition at line 155 of file nbd-server.c.

Referenced by handle_modern_connection(), handle_oldstyle_connection(), setup_servers(), sigchld_handler(), sigterm_handler(), and spawn_child().

gchar* config_file_pos

Where our config file actually is.

Definition at line 119 of file nbd-server.c.

Referenced by append_new_servers(), cmdline(), and main().

char default_authname[] = SYSCONFDIR "/nbd-server/allow"

default name of allow file

Definition at line 158 of file nbd-server.c.

Referenced by cmdline().

int dontfork = 0

Definition at line 125 of file nbd-server.c.

Referenced by cmdline(), handle_modern_connection(), handle_oldstyle_connection(), and main().

int glob_flags =0

global flags

Definition at line 122 of file nbd-server.c.

Referenced by cmdline(), handle_list(), main(), parse_cfile(), and setup_serve().

volatile sig_atomic_t is_sighup_caught

static

Flag set by SIGHUP handler to mark a reconfiguration request.

Definition at line 165 of file nbd-server.c.

Referenced by serveloop(), and sighup_handler().

bool logged_oversized =false

whether we logged oversized requests already

Definition at line 180 of file nbd-server.c.

Referenced by mainloop().

GArray* modernsocks

Sockets for the modern handler.

Not used if a client was only specified on the command line; only port used if oldstyle is set to false (and then the command-line client isn't used, gna gna). This may be more than one socket on systems that don't support serving IPv4 and IPv6 from the same socket (like, e.g., FreeBSD)

Definition at line 170 of file nbd-server.c.

Referenced by handle_modern_connection(), handle_oldstyle_connection(), main(), open_modern(), and serveloop().

char pidfname[256]

name of our PID file

Definition at line 156 of file nbd-server.c.

Referenced by daemonize(), and sigterm_handler().

char pidftemplate[256]

template to be used for the filename of the PID file

Definition at line 157 of file nbd-server.c.

Referenced by cmdline(), daemonize(), and main().