Network Block Device  @PACKAGE_VERSION@
Data Structures | Macros | Enumerations | Functions | Variables
nbd-server.c File Reference
#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/un.h>
#include <sys/ioctl.h>
#include <sys/param.h>
#include <sys/mount.h>
#include <signal.h>
#include <errno.h>
#include <libgen.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>

Go to the source code of this file.

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 TREEPAGESIZE   4096
 tree (block) files uses those chunks More...
 
#define TREEDIRSIZE   1024
 number of files per subdirectory (or subdirs per subdirectory) 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_TREEFILES   8192
 flag to tell us a file is exported using -t More...
 
#define F_OLDSTYLE   1
 Global flags: More...
 
#define F_LIST   2
 Allow clients to list the exports on a server. More...
 
#define F_NO_ZEROES   4
 Do not send zeros to client. More...
 
#define NEG_INIT   (1 << 0)
 
#define NEG_OLD   (1 << 1)
 
#define NEG_MODERN   (1 << 2)
 
#define NBD_D_TYPE   de->d_type
 
#define SEND(net, reply)
 sending macro. More...
 
#define ERROR(client, reply, errcode)   { reply.error = nbd_errno(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 myseek (int handle, off_t a)
 seek to a position in a file, with error handling. More...
 
static void construct_path (char *name, int lenmax, off_t size, off_t pos, off_t *ppos)
 Tree structure helper functions. More...
 
static void mkdir_path (char *path)
 
static int open_treefile (char *name, mode_t mode, off_t size, off_t pos)
 
static void delete_treefile (char *name, off_t size, off_t pos)
 
void usage ()
 Print out a message about how to use nbd-server. More...
 
void dump_section (SERVER *serve, gchar *section_header)
 
SERVERcmdline (int argc, char *argv[])
 Parse the command line. More...
 
GArray * parse_cfile (gchar *f, struct generic_conf *const genconf, bool expect_generic, GError **e)
 Parse the config file. More...
 
GArray * do_cfile_dir (gchar *dir, struct generic_conf *const genconf, GError **e)
 Parse config file snippets in a directory. More...
 
static void sigchld_handler (const int s G_GNUC_UNUSED)
 Handle SIGCHLD by setting atomically a flag which will be evaluated in the main loop of the root server process. More...
 
void killchild (gpointer key, gpointer value, gpointer user_data)
 Kill a child. More...
 
static void sigterm_handler (const int s G_GNUC_UNUSED)
 Handle SIGTERM by setting atomically a flag which will be evaluated in the main loop of the root server process. 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 (CLIENT *client, off_t a, int *fhandle, off_t *foffset, size_t *maxbytes)
 Get the file handle and offset, given an export offset. 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 CLIENThandle_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)
 
CLIENTnegotiate (int net, GArray *servers)
 Do the initial negotiation. More...
 
void send_export_info (CLIENT *client)
 
static int nbd_errno (int errcode)
 
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_unix (const gchar *const sockname, GError **const gerror)
 
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, const gchar *unixsock)
 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_sigchld_caught
 Flag set by SIGCHLD handler to mark a child exit. More...
 
static volatile sig_atomic_t is_sigterm_caught
 Flag set by SIGTERM handler to mark a exit request. 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 134 of file nbd-server.c.

Referenced by mainloop().

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

Definition at line 118 of file nbd-server.c.

Referenced by main(), and usage().

#define DIFFPAGESIZE   4096

diff file uses those chunks

Definition at line 135 of file nbd-server.c.

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

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

error macro.

Definition at line 1584 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 145 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 142 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 154 of file nbd-server.c.

#define F_FLUSH   128

Whether server wants FLUSH to be sent by the client.

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

Referenced by parse_cfile(), and send_export_info().

#define F_FUA   256

Whether server wants FUA to be sent by the client.

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

Referenced by parse_cfile(), and send_export_info().

#define F_LIST   2

Allow clients to list the exports on a server.

Definition at line 159 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 141 of file nbd-server.c.

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

#define F_NO_ZEROES   4

Do not send zeros to client.

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

Referenced by negotiate(), and send_export_info().

#define F_OLDSTYLE   1

Global flags:

Allow oldstyle (port-based) exports

Definition at line 158 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 140 of file nbd-server.c.

Referenced by cmdline(), dump_section(), expflush(), exptrim(), get_filepos(), mainloop(), parse_cfile(), send_export_info(), and setupexport().

#define F_ROTATIONAL   512

Whether server wants the client to implement the elevator algorithm.

Definition at line 151 of file nbd-server.c.

Referenced by parse_cfile(), and send_export_info().

#define F_SDP   32

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

Definition at line 147 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 146 of file nbd-server.c.

Referenced by expwrite(), and parse_cfile().

#define F_SYNC   64

Whether to fsync() after a write.

Definition at line 148 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 152 of file nbd-server.c.

Referenced by parse_cfile(), and setupexport().

#define F_TREEFILES   8192

flag to tell us a file is exported using -t

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

Referenced by dump_section(), expflush(), exptrim(), get_filepos(), parse_cfile(), rawexpread(), rawexpwrite(), and setupexport().

#define F_TRIM   2048

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

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

Referenced by parse_cfile(), and send_export_info().

#define MY_NAME   "nbd_server"

Definition at line 105 of file nbd-server.c.

Referenced by main().

#define NBD_D_TYPE   de->d_type

Definition at line 620 of file nbd-server.c.

Referenced by do_cfile_dir().

#define NEG_INIT   (1 << 0)

Definition at line 166 of file nbd-server.c.

#define NEG_MODERN   (1 << 2)

Definition at line 168 of file nbd-server.c.

#define NEG_OLD   (1 << 1)

Definition at line 167 of file nbd-server.c.

#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 133 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)); }
static void writeit(int f, void *buf, size_t len)
Write data from a buffer into a filedescriptor.
Definition: nbd-server.c:314

sending macro.

Definition at line 1580 of file nbd-server.c.

Referenced by mainloop().

#define SYSCONFDIR   "/etc"

Default position of the config file.

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

#define TREEDIRSIZE   1024

number of files per subdirectory (or subdirs per subdirectory)

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

Referenced by construct_path().

#define TREEPAGESIZE   4096

tree (block) files uses those chunks

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

Referenced by construct_path(), exptrim(), get_filepos(), open_treefile(), and setupexport().

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 209 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
serversan array of servers
Returns
the number of new servers appended to the array, or -1 in case of an error

Definition at line 2366 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[] 
)
static void construct_path ( char *  name,
int  lenmax,
off_t  size,
off_t  pos,
off_t *  ppos 
)
static

Tree structure helper functions.

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

References err(), TREEDIRSIZE, and TREEPAGESIZE.

Referenced by delete_treefile(), and open_treefile().

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
fa file descriptor
bufa buffer
lenthe number of bytes to consume
bufsizthe size of the buffer

Definition at line 298 of file nbd-server.c.

References readit().

Referenced by mainloop().

int copyonwrite_prepare ( CLIENT client)
void daemonize ( SERVER serve)

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

Parameters
servethe 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 2894 of file nbd-server.c.

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

Referenced by main().

static void delete_treefile ( char *  name,
off_t  size,
off_t  pos 
)
static

Definition at line 403 of file nbd-server.c.

References construct_path(), and DEBUG.

Referenced by exptrim().

void destroy_pid_t ( gpointer  data)

Destroy a pid_t*.

Parameters
dataa pointer to pid_t which should be freed

Definition at line 2068 of file nbd-server.c.

Referenced by setup_servers().

GArray* do_cfile_dir ( gchar *  dir,
struct generic_conf *const  genconf,
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 632 of file nbd-server.c.

References NBD_D_TYPE, 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
commandthe command to be ran. Read from the config file
filethe file name we're about to export

Definition at line 1907 of file nbd-server.c.

Referenced by serveconnection().

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

Set server socket options.

Parameters
socketa socket descriptor of the server
gerrora 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 2550 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 2932 of file nbd-server.c.

References err().

Referenced by main().

void dump_section ( SERVER serve,
gchar *  section_header 
)
int expflush ( CLIENT client)

Flush data to a client.

Parameters
clientThe client we're going to write for.
Returns
0 on success, nonzero on failure

Definition at line 1319 of file nbd-server.c.

References CLIENT::difffile, CLIENT::export, F_COPYONWRITE, F_READONLY, F_TREEFILES, 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
aThe offset where the read should start
bufA buffer to read into
lenThe size of buf
clientThe client we're going to read for
Returns
0 on success, nonzero on failure

Definition at line 1219 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 
)
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
aThe offset where the write should start
bufThe buffer to write from
lenThe length of buf
clientThe client we're going to write for.
fuaFlag to indicate 'Force Unit Access'
Returns
0 on success, nonzero on failure

Definition at line 1261 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 ( CLIENT client,
off_t  a,
int *  fhandle,
off_t *  foffset,
size_t *  maxbytes 
)

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

Parameters
clientThe client we're serving for
aThe 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 1006 of file nbd-server.c.

References CLIENT::export, CLIENT::exportname, CLIENT::exportsize, F_READONLY, F_TREEFILES, FILE_INFO::fhandle, SERVER::flags, open_treefile(), CLIENT::server, FILE_INFO::startoff, and TREEPAGESIZE.

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
servenamea string to match
serversan 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 2340 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
commandThe command number (after applying NBD_CMD_MASK_COMMAND)
Returns
pointer to the command name

Definition at line 251 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 2959 of file nbd-server.c.

Referenced by main().

static CLIENT* handle_export_name ( uint32_t  opt,
int  net,
GArray *  servers,
uint32_t  cflags 
)
static
static void handle_list ( uint32_t  opt,
int  net,
GArray *  servers,
uint32_t  cflags 
)
static
static void handle_modern_connection ( GArray *const  servers,
const int  sock 
)
static
static void handle_oldstyle_connection ( GArray *const  servers,
SERVER *const  serve 
)
static
void killchild ( gpointer  key,
gpointer  value,
gpointer  user_data 
)

Kill a child.

Called from sigterm_handler::g_hash_table_foreach.

Parameters
keythe key
valuethe value corresponding to the above key
user_dataa pointer which we always set to 1, so that we know what will happen next.

Definition at line 963 of file nbd-server.c.

Referenced by serveloop().

int main ( int  argc,
char *  argv[] 
)
int mainloop ( CLIENT client)
static void mkdir_path ( char *  path)
static

Definition at line 348 of file nbd-server.c.

References err().

Referenced by open_treefile().

void myseek ( int  handle,
off_t  a 
)

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

Parameters
handlea filedescriptor
aposition to seek to
Todo:
get rid of this.

Definition at line 1060 of file nbd-server.c.

References err().

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

static int nbd_errno ( int  errcode)
static

Definition at line 1558 of file nbd-server.c.

CLIENT* negotiate ( int  net,
GArray *  servers 
)
int open_modern ( const gchar *const  addr,
const gchar *const  port,
GError **const  gerror 
)
static int open_treefile ( char *  name,
mode_t  mode,
off_t  size,
off_t  pos 
)
static

Definition at line 361 of file nbd-server.c.

References construct_path(), DEBUG, err(), handle, mkdir_path(), myseek(), and TREEPAGESIZE.

Referenced by get_filepos().

int open_unix ( const gchar *const  sockname,
GError **const  gerror 
)

Definition at line 2694 of file nbd-server.c.

References modernsocks, NBDS_ERR, NBDS_ERR_BIND, and NBDS_ERR_SOCKET.

Referenced by setup_servers().

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

Parse the config file.

Parameters
fthe name of the config file
genconfa pointer to generic configuration which will get updated with parsed values. If NULL, then parsed generic configuration values are safely and silently discarded.
ea 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.
Parameters
expect_genericif true, we expect a configuration file that contains a [generic] section. If false, we don't.
Returns
a GArray of SERVER* pointers. If the config file is empty or does not exist, returns an empty GArray; if the config file contains an error, returns NULL, and e is set appropriately

Definition at line 713 of file nbd-server.c.

References append_serve(), SERVER::authname, SERVER::cidrlen, SERVER::cowdir, 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_TREEFILES, F_TRIM, SERVER::flags, generic_conf::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::postrun, SERVER::prerun, SERVER::servename, SERVER::socket_family, SERVER::transactionlog, generic_conf::unixsock, 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
aThe offset where the read should start
bufA buffer to read into
lenThe size of buf
clientThe client we're serving for
Returns
The number of bytes actually read, or -1 in case of an error.

Definition at line 1173 of file nbd-server.c.

References DEBUG, F_TREEFILES, SERVER::flags, get_filepos(), myseek(), and CLIENT::server.

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 1198 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
aThe offset where the write should start
bufThe buffer to write from
lenThe length of buf
clientThe client we're serving for
fuaFlag to indicate 'Force Unit Access'
Returns
The number of bytes actually written, or -1 in case of an error

Definition at line 1077 of file nbd-server.c.

References DEBUG, F_SYNC, F_TREEFILES, 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
aThe offset where the write should start
bufThe buffer to write from
lenThe length of buf
clientThe client we're serving for
fuaFlag to indicate 'Force Unit Access'
Returns
0 on success, nonzero on failure

Definition at line 1151 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
fa file descriptor
bufa buffer
lenthe number of bytes to be read

Definition at line 275 of file nbd-server.c.

References DEBUG, and err().

Referenced by consume(), and mainloop().

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

Definition at line 1385 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
clienta connected client

Definition at line 1927 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 2400 of file nbd-server.c.

References append_new_servers(), children, DEBUG, err(), handle_modern_connection(), handle_oldstyle_connection(), is_sigchld_caught, is_sighup_caught, is_sigterm_caught, killchild(), len, modernsocks, msg, pidfname, 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
netA socket connected to an nbd client
clientinformation 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 1970 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
servethe server we want to connect.

Definition at line 2588 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,
const gchar *  unixsock 
)

Connect our servers.

Definition at line 2825 of file nbd-server.c.

References children, destroy_pid_t(), err(), msg, open_modern(), open_unix(), 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
clientinformation on the client which we want to setup export for

Definition at line 1764 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, F_TREEFILES, FILE_INFO::fhandle, SERVER::flags, msg, CLIENT::server, size_autodetect(), FILE_INFO::startoff, and TREEPAGESIZE.

Referenced by serveconnection().

static void sigchld_handler ( const int s  G_GNUC_UNUSED)
static

Handle SIGCHLD 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 SIGCHLD and hence processing in the interrupt context is kept as minimial as possible.

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

Definition at line 951 of file nbd-server.c.

References is_sigchld_caught.

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

Definition at line 991 of file nbd-server.c.

References is_sighup_caught.

Referenced by setup_servers().

static void sigterm_handler ( const int s  G_GNUC_UNUSED)
static

Handle SIGTERM 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 SIGTERM and hence processing in the interrupt context is kept as minimial as possible.

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

Definition at line 978 of file nbd-server.c.

References is_sigterm_caught.

Referenced by setup_servers().

static int socket_accept ( const int  sock)
static

Definition at line 2109 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 2073 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 421 of file nbd-server.c.

References CFILE, and VERSION.

Referenced by cmdline().

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

Write data from a buffer into a filedescriptor.

Parameters
fa file descriptor
bufa buffer containing data
lenthe number of bytes to be written

Definition at line 314 of file nbd-server.c.

References DEBUG, and err().

Referenced by mainloop().

Variable Documentation

GHashTable* children
gchar* config_file_pos

Where our config file actually is.

Definition at line 121 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 164 of file nbd-server.c.

Referenced by cmdline().

int dontfork = 0

Definition at line 127 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 124 of file nbd-server.c.

Referenced by cmdline(), handle_list(), main(), negotiate(), send_export_info(), and setup_serve().

volatile sig_atomic_t is_sigchld_caught
static

Flag set by SIGCHLD handler to mark a child exit.

Definition at line 171 of file nbd-server.c.

Referenced by serveloop(), and sigchld_handler().

volatile sig_atomic_t is_sighup_caught
static

Flag set by SIGHUP handler to mark a reconfiguration request.

Definition at line 181 of file nbd-server.c.

Referenced by serveloop(), and sighup_handler().

volatile sig_atomic_t is_sigterm_caught
static

Flag set by SIGTERM handler to mark a exit request.

Definition at line 176 of file nbd-server.c.

Referenced by serveloop(), and sigterm_handler().

bool logged_oversized =false

whether we logged oversized requests already

Definition at line 196 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 186 of file nbd-server.c.

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

char pidfname[256]

name of our PID file

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

Referenced by daemonize(), and serveloop().

char pidftemplate[256]

template to be used for the filename of the PID file

Definition at line 163 of file nbd-server.c.

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