afp_dsi.c File Reference

#include <arpa/inet.h>
#include <errno.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <poll.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>
#include <atalk/afp_util.h>
#include <atalk/compat.h>
#include <atalk/dsi.h>
#include <atalk/fce_api.h>
#include <atalk/globals.h>
#include <atalk/logger.h>
#include <atalk/netatalk_conf.h>
#include <atalk/server_ipc.h>
#include <atalk/spotlight.h>
#include <atalk/util.h>
#include <atalk/uuid.h>
#include "auth.h"
#include "dircache.h"
#include "directory.h"
#include "fork.h"
#include "idle_worker.h"
#include "switch.h"

Data Structures
struct	rc_elem_t

Macros
#define	SOL_TCP   IPPROTO_TCP

Functions
static void	sigpipe_init (void)
static void	sigpipe_notify (void)
	Write a single byte to the self-pipe.
static void	sigpipe_drain (void)
	Drain all pending bytes from the self-pipe.
static void	afp_dsi_close (AFPObj *obj)
static void	afp_dsi_die (int sig)
	SIGTERM: Terminate the AFP session and exit.
static void	afp_dsi_transfer_handler (int sig)
static void	handle_transfer_session (AFPObj *obj)
	Process deferred SIGURG: primary reconnect.
static void	afp_dsi_die_handler (int sig)
static void	afp_dsi_timedown_handler (int sig)
static void	handle_timedown (AFPObj *obj)
	Process deferred SIGUSR1: server going down in 5 minutes.
static void	afp_dsi_reload (int sig)
static void	afp_dsi_debug (int sig)
static void	afp_dsi_getmesg_handler (int sig)
static void	handle_getmesg (AFPObj *obj)
	Process deferred SIGUSR2: server message.
static void	alarm_handler (int sig)
	SIGALRM handler — async-signal-safe.
static void	handle_alarm (AFPObj *obj)
	Process deferred SIGALRM: tickle/timeout management.
static void	child_handler (int sig)
static int	process_deferred_signals (AFPObj *obj)
	Process all pending deferred signals.
static void	pending_request (DSI *dsi)
void	afp_over_dsi_sighandlers (AFPObj *obj)
void	afp_over_dsi (AFPObj *obj)

Variables
AFPObj *	AFPobj = NULL
static rc_elem_t	replaycache [REPLAYCACHE_SIZE]
static volatile sig_atomic_t	alarm_pending = 0
static volatile sig_atomic_t	transfer_pending = 0
static volatile sig_atomic_t	timedown_pending = 0
static volatile sig_atomic_t	getmesg_pending = 0
volatile sig_atomic_t	die_pending = 0
static int	sigpipe_fd [2] = {-1, -1}
	Self-pipe for waking poll() from signal handlers.
volatile sig_atomic_t	reload_request = 0
static volatile sig_atomic_t	debug_request = 0

Macro Definition Documentation

SOL_TCP

#define SOL_TCP   IPPROTO_TCP

Function Documentation

afp_dsi_close()

void afp_dsi_close ( AFPObj * obj )

static

afp_dsi_debug()

void afp_dsi_debug ( int sig )

static

afp_dsi_die()

void afp_dsi_die ( int sig )

static

SIGTERM: Terminate the AFP session and exit.

Wraps afp_dsi_close() + exit() with pre-flight checks and a shutdown attention to notify the client. Other call sites in this file invoke afp_dsi_close() + exit() directly — a future cleanup could funnel all exit paths through here.

Parameters

sig	signal number or EXITERR_* code; 0 for maintenance shutdown.

afp_dsi_die_handler()

void afp_dsi_die_handler ( int sig )

static

SIGTERM/SIGQUIT handler — async-signal-safe

afp_dsi_getmesg_handler()

void afp_dsi_getmesg_handler ( int sig )

static

SIGUSR2 handler — async-signal-safe

afp_dsi_reload()

void afp_dsi_reload ( int sig )

static

afp_dsi_timedown_handler()

void afp_dsi_timedown_handler ( int sig )

static

SIGUSR1 handler — async-signal-safe

afp_dsi_transfer_handler()

void afp_dsi_transfer_handler ( int sig )

static

SIGURG handler (primary reconnect) — async-signal-safe

afp_over_dsi()

void afp_over_dsi

(

AFPObj *

obj

)

afp_over_dsi_sighandlers()

void afp_over_dsi_sighandlers

(

AFPObj *

obj

)

alarm_handler()

void alarm_handler ( int sig )

static

SIGALRM handler — async-signal-safe.

Only restarts the timer (setitimer is async-signal-safe) and sets a flag. All tickle/timeout logic is deferred to handle_alarm().

child_handler()

void child_handler ( int sig )

static

handle_alarm()

void handle_alarm ( AFPObj * obj )

static

Process deferred SIGALRM: tickle/timeout management.

Called from the main event loop where LOG/malloc/syslog are safe.

handle_getmesg()

void handle_getmesg ( AFPObj * obj )

static

Process deferred SIGUSR2: server message.

Called from the main event loop.

handle_timedown()

void handle_timedown ( AFPObj * obj )

static

Process deferred SIGUSR1: server going down in 5 minutes.

Called from the main event loop.

handle_transfer_session()

void handle_transfer_session ( AFPObj * obj )

static

Process deferred SIGURG: primary reconnect.

Called from the main event loop where non-signal-safe functions are permitted.

pending_request()

void pending_request ( DSI * dsi )

static

process_deferred_signals()

int process_deferred_signals ( AFPObj * obj )

static

Process all pending deferred signals.

Returns

1 if the caller should restart the outer event loop (primary reconnect), 0 otherwise.

Note

Must be called from the main event loop, never from signal context.

sigpipe_drain()

void sigpipe_drain ( void )

static

Drain all pending bytes from the self-pipe.

Called from the main loop after poll() returns.

sigpipe_init()

void sigpipe_init ( void )

static

sigpipe_notify()

void sigpipe_notify ( void )

static

Write a single byte to the self-pipe.

Called from signal handlers — async-signal-safe.

Variable Documentation

AFPobj

AFPObj* AFPobj = NULL

We generally pass this from afp_over_dsi to all afp_* funcs, so it should already be available everywhere. Unfortunately some funcs (eg acltoownermode) need acces to it but are deeply nested in the function chain with the caller already without acces to it. Changing this would require adding a reference to the caller which itself might be called in many places (eg acltoownermode is called from accessmode). The only sane way out is providing a copy of it here:

alarm_pending

volatile sig_atomic_t alarm_pending = 0

static

debug_request

volatile sig_atomic_t debug_request = 0

static

SIGINT: enable max_debug LOGging — async-signal-safe

die_pending

volatile sig_atomic_t die_pending = 0

getmesg_pending

volatile sig_atomic_t getmesg_pending = 0

static

reload_request

volatile sig_atomic_t reload_request = 0

SIGHUP: reload configuration file — async-signal-safe

replaycache

rc_elem_t replaycache[REPLAYCACHE_SIZE]

static

AFP replay cache:

• fix sized array
• indexed just by taking DSIreqID mod REPLAYCACHE_SIZE

sigpipe_fd

int sigpipe_fd[2] = {-1, -1}

static

Self-pipe for waking poll() from signal handlers.

Signal handlers write a single byte to sigpipe_fd[1]. The read end sigpipe_fd[0] is included in the poll() set so that the main loop wakes up promptly even when SA_RESTART would otherwise cause poll() to be restarted transparently.

Although POSIX says poll() is not affected by SA_RESTART, some platforms (Solaris, illumos) have historically restarted it. The self-pipe makes wake-up behaviour portable and deterministic.

timedown_pending

volatile sig_atomic_t timedown_pending = 0

static

transfer_pending

volatile sig_atomic_t transfer_pending = 0

static