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lsyncd/lsyncd.c
Daniel Poelzleithner dd84b2e6b6 lua 5.4 fixes
2022-06-03 07:07:08 +02:00

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/*
| lsyncd.c Live (Mirror) Syncing Demon
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
| This is Lsyncd's core.
|
| It contains as minimal as possible glues to the operating system needed
| for Lsyncd's operation. All high-level logic is coded (when feasable)
| into lsyncd.lua
|
| This code assumes you have a 100 character wide display to view it (when tabstop is 4)
|
| License: GPLv2 (see COPYING) or any later version
| Authors: Axel Kittenberger <axkibe@gmail.com>
|
*/
#include "lsyncd.h"
#define SYSLOG_NAMES 1
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/select.h>
#include <sys/stat.h>
#include <sys/times.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <signal.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <strings.h>
#include <syslog.h>
#include <math.h>
#include <time.h>
#include <unistd.h>
#define LUA_USE_APICHECK 1
#include <lua.h>
#include <lualib.h>
#include <lauxlib.h>
#if defined(LUA_VERSION_NUM) && LUA_VERSION_NUM >= 504
#define lua_objlen lua_rawlen
#endif
/*
| The Lua part of Lsyncd
*/
extern const char runner_out[];
extern size_t runner_size;
extern const char defaults_out[];
extern size_t defaults_size;
/*
| Makes sure there is one file system monitor.
*/
#ifndef WITH_INOTIFY
#ifndef WITH_FSEVENTS
# error "needing at least one notification system. please rerun cmake"
#endif
#endif
/*
| All monitors supported by this Lsyncd.
*/
static char *monitors[] = {
#ifdef WITH_INOTIFY
"inotify",
#endif
#ifdef WITH_FSEVENTS
"fsevents",
#endif
NULL,
};
/**
| Configuration parameters that matter to the core
*/
struct settings settings = {
.log_file = NULL,
.log_syslog = false,
.log_ident = NULL,
.log_facility = LOG_USER,
.log_level = LOG_NOTICE,
.nodaemon = false,
};
/*
| True when Lsyncd daemonized itself.
*/
static bool is_daemon = false;
/*
| The config file loaded by Lsyncd.
*/
char * lsyncd_config_file = NULL;
/*
| False after first time Lsyncd started up.
|
| Configuration error messages are thus written to
| stdout/stderr only on first start.
|
| All other resets (HUP or monitor OVERFLOW) run with 'insist'
| implictly turned on and thus Lsyncd does not failing on a non
| responding target.
*/
static bool first_time = true;
/*
| Set by TERM or HUP signal handler
| telling Lsyncd should end or reset ASAP.
*/
volatile sig_atomic_t hup = 0;
volatile sig_atomic_t term = 0;
volatile sig_atomic_t sigcode = 0;
int pidfile_fd = 0;
/*
| The kernel's clock ticks per second.
*/
static long clocks_per_sec;
/*
| Dummy variable of which it's address is used as
| the cores index in the lua registry to
| the lua runners function table in the lua registry.
*/
static int runner;
/*
| Dummy variable of which it's address is used as
| the cores index n the lua registry to
| the lua runners error handler.
*/
static int callError;
/**
* signal handler
*/
void
sig_child(int sig) {
// nothing
}
/**
* signal handler
*/
void
sig_handler( int sig )
{
switch( sig )
{
case SIGTERM:
case SIGINT:
term = 1;
sigcode = sig;
return;
case SIGHUP:
hup = 1;
return;
}
}
/*
| Non glibc builds need a real tms structure for the times( ) call
*/
#ifdef __GLIBC__
static struct tms * dummy_tms = NULL;
#else
static struct tms _dummy_tms;
static struct tms * dummy_tms = &_dummy_tms;
#endif
/*
| Returns the absolute path of a path.
|
| This is a wrapper to various C-Library differences.
*/
char *
get_realpath( const char * rpath )
{
// uses c-library to get the absolute path
#ifdef __GLIBC__
// in case of GLIBC the task is easy.
return realpath( rpath, NULL );
#else
# warning having to use old style realpath()
// otherwise less so and requires PATH_MAX limit
char buf[ PATH_MAX] ;
char *asw = realpath( rpath, buf );
if( !asw )
{ return NULL; }
return s_strdup( asw );
#endif
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*
( Logging )
*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/*
| A logging category
*/
struct logcat
{
char *name;
int priority;
};
/*
| A table of all enabled logging categories.
| Sorted by first letter for faster access.
*/
static struct logcat *
logcats[ 26 ] = { 0, };
/*
| Returns a positive priority if category is configured to be logged or -1.
*/
extern int
check_logcat( const char *name )
{
struct logcat *lc;
if( name[ 0 ] < 'A' || name[ 0 ] > 'Z')
{ return 99; }
lc = logcats[ name[ 0 ] - 'A' ];
if( !lc )
{ return 99; }
while( lc->name )
{
if( !strcmp( lc->name, name ) )
{ return lc->priority; }
lc++;
}
return 99;
}
/*
| Adds a logging category
|
| Returns true if OK.
*/
static bool
add_logcat( const char *name, int priority )
{
struct logcat *lc;
if( !strcmp( "all", name ) )
{
settings.log_level = 99;
return true;
}
if( !strcmp( "scarce", name ) )
{
settings.log_level = LOG_WARNING;
return true;
}
// categories must start with a capital letter.
if( name[ 0 ] < 'A' || name[ 0 ] > 'Z' )
{
return false;
}
if( !logcats[ name[ 0 ]- 'A' ] )
{
// an empty capital letter
lc = logcats[name[0]-'A'] = s_calloc(2, sizeof(struct logcat));
}
else
{
// length of letter list
int ll = 0;
// counts list length
for( lc = logcats[name[0]-'A']; lc->name; lc++ )
{ ll++; }
// enlarges list
logcats[ name[ 0 ] - 'A'] =
s_realloc(
logcats[ name[ 0 ]-'A' ],
( ll + 2 ) * sizeof( struct logcat )
);
// goes to the list end
for( lc = logcats[ name[ 0 ] - 'A']; lc->name; lc++ )
{
if( !strcmp( name, lc->name ) )
{
// already there
return true;
}
}
}
lc->name = s_strdup( name );
lc->priority = priority;
// terminates the list
lc[ 1 ].name = NULL;
return true;
}
/*
| Logs a string.
|
| Do not call this directly, but the macro logstring( )
| defined in lsyncd.h
*/
extern void
logstring0(
int priority, // the priority of the log message
const char * cat, // the category
const char * message // the log message
)
{
if( first_time )
{
// lsyncd is in it's intial configuration phase.
// thus just print to normal stdout/stderr.
if( priority >= LOG_ERR )
{
fprintf( stderr, "%s: %s\n", cat, message);
}
else
{
printf( "%s: %s\n", cat, message );
}
return;
}
// writes on console if not daemonized
if( !is_daemon )
{
char ct[ 255 ];
// gets current timestamp hour:minute:second
time_t mtime;
time( &mtime );
strftime( ct, sizeof( ct ), "%T", localtime( &mtime ) );
FILE * flog = priority <= LOG_ERR ? stderr : stdout;
fprintf(
flog,
"%s %s: %s\n",
ct, cat, message
);
}
// writes to file if configured so
if( settings.log_file )
{
FILE * flog = fopen( settings.log_file, "a" );
char * ct;
time_t mtime;
// gets current timestamp day-time-year
time( &mtime );
ct = ctime( &mtime );
// cuts trailing linefeed
ct[ strlen( ct ) - 1] = 0;
if( flog == NULL )
{
fprintf(
stderr,
"Cannot open logfile [%s]!\n",
settings.log_file
);
exit( -1 );
}
fprintf(
flog,
"%s %s: %s\n",
ct, cat, message
);
fclose( flog );
}
// sends to syslog if configured so
if( settings.log_syslog )
{
syslog( priority, "%s, %s", cat, message );
}
return;
}
/*
| Lets the core print logmessages comfortably as formated string.
| This uses the lua_State for it easy string buffers only.
*/
extern void
printlogf0(lua_State *L,
int priority,
const char *cat,
const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
lua_pushvfstring(L, fmt, ap);
va_end(ap);
logstring0(priority, cat, luaL_checkstring(L, -1));
lua_pop(L, 1);
return;
}
/*
| Print a traceback of the error
*/
static int l_traceback (lua_State *L) {
// runner.callError
lua_getglobal(L, "debug");
lua_getfield(L, -1, "traceback");
lua_pushvalue(L, 1);
lua_pushinteger(L, 2);
lua_call(L, 2, 1);
printlogf( L, "traceback", "%s", lua_tostring(L, -1) );
return 1;
}
/*
| Call runners terminate function and exit with given exit code
*/
static void safeexit (lua_State *L, int exitcode) {
// load_runner_func(L, "teardown");
// pushes the function
lua_pushlightuserdata( L, (void *) &runner );
lua_gettable( L, LUA_REGISTRYINDEX );
lua_pushstring( L, "teardown" );
lua_gettable( L, -2 );
lua_remove( L, -2 );
lua_pushinteger(L, exitcode);
lua_call(L, 2, 1);
if (lua_isnumber(L, -1)) {
exitcode = luaL_checkinteger(L, -1);
}
exit(exitcode);
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*
( Simple memory management )
*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
// FIXME call the Lua garbace collector in case of out of memory
/*
| "Secured" calloc
*/
extern void *
s_calloc( size_t nmemb, size_t size )
{
void * r = calloc( nmemb, size );
if( r == NULL )
{
logstring0(
LOG_ERR,
"Error",
"Out of memory!"
);
exit( -1 );
}
return r;
}
/*
| "Secured" malloc
*/
extern void *
s_malloc( size_t size )
{
void * r = malloc( size );
if( r == NULL )
{
logstring0(
LOG_ERR,
"Error",
"Out of memory!"
);
exit( -1 );
}
return r;
}
/*
| "Secured" realloc
*/
extern void *
s_realloc( void * ptr, size_t size )
{
void * r = realloc( ptr, size );
if( r == NULL )
{
logstring0(
LOG_ERR,
"Error",
"Out of memory!"
);
exit( -1 );
}
return r;
}
/*
| "Secured" strdup
*/
extern char *
s_strdup( const char *src )
{
char *s = strdup( src );
if( s == NULL )
{
logstring0(
LOG_ERR,
"Error",
"Out of memory!"
);
exit( -1 );
}
return s;
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*
( Pipes Management )
*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/*
| A child process gets text piped through stdin
*/
struct pipemsg
{
char * text; // message to send
int tlen; // length of text
int pos; // position in message
};
/*
| Called by the core whenever a pipe becomes
| writeable again
*/
static void
pipe_writey(
lua_State * L,
struct observance * observance
)
{
int fd = observance->fd;
struct pipemsg *pm = (struct pipemsg * ) observance->extra;
int len = write(
fd,
pm->text + pm->pos,
pm->tlen - pm->pos
);
pm->pos += len;
if( len < 0 )
{
logstring( "Normal", "broken pipe." );
nonobserve_fd( fd );
}
else if( pm->pos >= pm->tlen )
{
logstring( "Exec", "finished pipe." );
nonobserve_fd(fd);
}
}
/*
| Called when cleaning up a pipe.
*/
static void
pipe_tidy( struct observance * observance )
{
struct pipemsg *pm = ( struct pipemsg * ) observance->extra;
close( observance->fd );
free( pm->text );
free( pm );
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*
( Helper Routines )
*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/*
| Sets the close-on-exit flag of a file descriptor.
*/
extern void
close_exec_fd( int fd )
{
int flags;
flags = fcntl( fd, F_GETFD );
if( flags == -1 )
{
logstring( "Error", "cannot get descriptor flags!" );
exit( -1 );
}
flags |= FD_CLOEXEC;
if( fcntl( fd, F_SETFD, flags ) == -1 )
{
logstring( "Error", "cannot set descripptor flags!" );
exit( -1 );
}
}
/*
| Sets the non-blocking flag of a file descriptor.
*/
extern void
non_block_fd( int fd )
{
int flags;
flags = fcntl( fd, F_GETFL );
if( flags == -1 )
{
logstring( "Error", "cannot get status flags!" );
exit( -1 );
}
flags |= O_NONBLOCK;
if( fcntl( fd, F_SETFL, flags ) == -1 )
{
logstring( "Error", "cannot set status flags!" );
exit( -1 );
}
}
/*
| Writes a pid file.
*/
static void
write_pidfile
(
lua_State *L,
const char *pidfile
)
{
pidfile_fd = open( pidfile, O_CREAT | O_RDWR, 0644 );
fcntl( pidfile_fd, F_SETFD, FD_CLOEXEC );
char buf[ 127 ];
if( pidfile_fd < 0 )
{
printlogf(
L, "Error",
"Cannot create pidfile; '%s'",
pidfile
);
safeexit(L, -1 );
}
int rc = lockf( pidfile_fd, F_TLOCK, 0 );
if( rc < 0 )
{
printlogf(
L, "Error",
"Cannot lock pidfile; '%s'",
pidfile
);
safeexit(L, -1 );
}
snprintf( buf, sizeof( buf ), "%i\n", getpid( ) );
if (write( pidfile_fd, buf, strlen( buf ) ) != strlen(buf)) {
printlogf(
L, "Error",
"Cannot write pidfile; '%s'",
pidfile
);
safeexit(L, -1 );
}
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*
( Observances )
*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/*
| List of file descriptor watches.
*/
static struct observance * observances = NULL;
static int observances_len = 0;
static int observances_size = 0;
/*
| List of file descriptors to not observe.
|
| While working for the oberver lists, it may
| not be altered, thus nonobserve stores the
| delayed removals.
*/
static int * nonobservances = NULL;
static int nonobservances_len = 0;
static int nonobservances_size = 0;
/*
| True while the observances list is being handled.
*/
static bool observance_action = false;
/*
| Core watches a filedescriptor to become ready,
| one of read_ready or write_ready may be zero
*/
extern void
observe_fd(
int fd,
void ( * ready ) (lua_State *, struct observance * ),
void ( * writey ) (lua_State *, struct observance * ),
void ( * tidy ) (struct observance * ),
void *extra
)
{
int pos;
// looks if the fd is already there as pos or
// stores the position to insert the new fd in pos
for( pos = 0; pos < observances_len; pos++)
{
if( fd <= observances[ pos ].fd )
{ break; }
}
if( pos < observances_len && observances[ pos ].fd == fd )
{
// just updates an existing observance
logstring( "Masterloop", "updating fd observance" );
observances[ pos ].ready = ready;
observances[ pos ].writey = writey;
observances[ pos ].tidy = tidy;
observances[ pos ].extra = extra;
return;
}
if( observance_action )
{
// FIXME
logstring(
"Error",
"New observances in ready/writey handlers not yet supported"
);
exit( -1 );
}
if( !tidy )
{
logstring(
"Error",
"internal, tidy() in observe_fd() must not be NULL."
);
exit( -1 );
}
if( observances_len + 1 > observances_size )
{
observances_size = observances_len + 1;
observances = s_realloc(
observances,
observances_size * sizeof( struct observance )
);
}
memmove(
observances + pos + 1,
observances + pos,
(observances_len - pos) * sizeof(struct observance)
);
observances_len++;
observances[ pos ].fd = fd;
observances[ pos ].ready = ready;
observances[ pos ].writey = writey;
observances[ pos ].tidy = tidy;
observances[ pos ].extra = extra;
}
/*
| Makes the core no longer watch a filedescriptor.
*/
extern void
nonobserve_fd( int fd )
{
int pos;
if( observance_action )
{
// this function is called through a ready/writey handler
// while the core works through the observance list, thus
// it does not alter the list, but stores this actions
// on a stack
nonobservances_len++;
if( nonobservances_len > nonobservances_size )
{
nonobservances_size = nonobservances_len;
nonobservances = s_realloc(
nonobservances,
nonobservances_size * sizeof( int )
);
}
nonobservances[ nonobservances_len - 1 ] = fd;
return;
}
// looks for the fd
for( pos = 0; pos < observances_len; pos++ )
{
if( observances[ pos ].fd == fd )
{ break; }
}
if( pos >= observances_len )
{
logstring(
"Error",
"internal fail, not observance file descriptor in nonobserve"
);
exit( -1 );
}
// tidies up the observance
observances[ pos ].tidy( observances + pos );
// and moves the list down
memmove(
observances + pos,
observances + pos + 1,
(observances_len - pos) * sizeof( struct observance )
);
observances_len--;
}
/*
| A user observance became read-ready.
*/
static void
user_obs_ready(
lua_State * L,
struct observance * obs
)
{
int fd = obs->fd;
// pushes the ready table on table
lua_pushlightuserdata( L, ( void * ) user_obs_ready );
lua_gettable( L, LUA_REGISTRYINDEX );
// pushes the error handler
lua_pushlightuserdata( L, (void *) &callError );
lua_gettable( L, LUA_REGISTRYINDEX );
// pushes the user func
lua_pushnumber( L, fd );
lua_gettable( L, -3 );
// gives the ufunc the fd
lua_pushnumber( L, fd );
// calls the user function
if( lua_pcall( L, 1, 0, -3 ) )
{
safeexit(L, -1 );
}
lua_pop( L, 2 );
}
/*
| A user observance became write-ready
*/
static void
user_obs_writey(
lua_State * L,
struct observance * obs
)
{
int fd = obs->fd;
// pushes the writey table on table
lua_pushlightuserdata( L, (void *) user_obs_writey );
lua_gettable( L, LUA_REGISTRYINDEX );
// pushes the error handler
lua_pushlightuserdata(L, (void *) &callError);
lua_gettable( L, LUA_REGISTRYINDEX );
// pushes the user func
lua_pushnumber( L, fd );
lua_gettable( L, -3 );
// gives the user func the fd
lua_pushnumber( L, fd );
// calls the user function
if( lua_pcall( L, 1, 0, -3 ) )
{
safeexit(L, -1);
}
lua_pop( L, 2 );
}
/*
| Tidies up a user observance
| FIXME - give the user a chance to do something in that case!
*/
static void
user_obs_tidy( struct observance *obs )
{
close( obs->fd );
}
/******************************.
* Library calls for the runner *
'******************************/
static void daemonize( lua_State *L, const char *pidfile );
int l_stackdump( lua_State* L );
/*
| Logs a message.
|
| Params on Lua stack:
|
| 1: loglevel of massage
| 2: the string to log
*/
static int
l_log( lua_State *L )
{
const char * cat; // log category
const char * message; // log message
int priority; // log priority
cat = luaL_checkstring( L, 1 );
priority = check_logcat( cat );
// skips filtered messages
if( priority > settings.log_level )
{
return 0;
}
// replaces non string values
{
int i;
int top = lua_gettop(L);
for( i = 1; i <= top; i++ )
{
int t = lua_type( L, i );
switch( t )
{
case LUA_TTABLE :
lua_pushfstring(
L,
"(Table: %p)",
lua_topointer( L, i )
);
lua_replace( L, i );
break;
case LUA_TBOOLEAN :
if( lua_toboolean( L, i ) )
{ lua_pushstring( L, "(true)" ); }
else
{ lua_pushstring( L, "(false)" ); }
lua_replace(L, i);
break;
case LUA_TUSERDATA:
{
clock_t *c = ( clock_t * )
luaL_checkudata( L, i, "Lsyncd.jiffies" );
double d = *c;
d /= clocks_per_sec;
lua_pushfstring( L, "(Timestamp: %f)", d );
lua_replace( L, i );
}
break;
case LUA_TNIL:
lua_pushstring( L, "(nil)" );
lua_replace( L, i );
break;
}
}
}
// concates if there is more than one string parameter
lua_concat( L, lua_gettop( L ) - 1 );
message = luaL_checkstring( L, 2 );
logstring0( priority, cat, message );
return 0;
}
/*
| Returns (on Lua stack) the current kernels
| clock state (jiffies)
*/
extern int
l_now(lua_State *L)
{
clock_t * j = lua_newuserdata( L, sizeof( clock_t ) );
luaL_getmetatable( L, "Lsyncd.jiffies" );
lua_setmetatable( L, -2 );
*j = times( dummy_tms );
return 1;
}
/*
| Sends a signal to proceess pid
|
| Params on Lua stack:
| 1: pid
| 2: signal
|
| Returns on Lua stack:
| return value of kill
*/
static int
l_kill( lua_State *L )
{
pid_t pid = luaL_checkinteger( L, 1 );
int sig = luaL_checkinteger( L, 2 );
int rv = kill(pid, sig );
lua_pushinteger( L, rv );
return 1;
}
/*
| Returns a free port of host
|
| Params on Lua stack:
| (not yet) 1: hostname or ip for bind
|
| Returns on Lua stack:
| return integer of free port
|
*/
static int
l_free_port(lua_State *L) {
int sock = socket(AF_INET, SOCK_STREAM, 0);
if(sock < 0) {
printf("error opening socket\n");
goto error;
}
struct sockaddr_in serv_addr;
memset((char *) &serv_addr, 0, sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
serv_addr.sin_addr.s_addr = INADDR_ANY;
serv_addr.sin_port = 0;
if (bind(sock, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0) {
if(errno == EADDRINUSE) {
printf("the port is not available. already to other process\n");
goto error;
} else {
printf("could not bind to process (%d) %s\n", errno, strerror(errno));
goto error;
}
}
socklen_t len = sizeof(serv_addr);
if (getsockname(sock, (struct sockaddr *)&serv_addr, &len) == -1) {
goto error;
}
lua_pushinteger(L, ntohs(serv_addr.sin_port));
if (close (sock) < 0 ) {
printf("did not close: %s\n", strerror(errno));
lua_pop ( L, 1 );
goto error;
}
return 1;
error:
lua_pushnil(L);
return 1;
}
/*
| Executes a subprocess. Does not wait for it to return.
|
| Params on Lua stack:
|
| 1: Path to binary to call
| 2: List of string as arguments
| or "<" in which case the next argument is a string
| that will be piped on stdin.
| The arguments will follow that one.
|
| Returns (Lua stack) the pid on success, 0 on failure.
*/
static int
l_exec( lua_State *L )
{
// the binary to call
const char *binary = luaL_checkstring(L, 1);
l_stackdump(L);
// number of arguments
int argc = lua_gettop( L ) - 1;
// the pid spawned
pid_t pid;
// the arguments position in the lua arguments
int li = 1;
// the pipe to text
char const * pipe_text = NULL;
// the pipes length
size_t pipe_len = 0;
// the arguments
char const ** argv;
// pipe file descriptors
int pipefd[ 2 ];
int i;
// expands tables
// and removes nils
for( i = 1; i <= lua_gettop( L ); i++ )
{
if( lua_isnil( L, i ) )
{
lua_remove( L, i );
i--;
argc--;
continue;
}
if( lua_istable( L, i ) )
{
int tlen;
int it;
lua_checkstack( L, lua_gettop( L ) + lua_objlen( L, i ) + 1 );
// moves table to top of stack
lua_pushvalue( L, i );
lua_remove( L, i );
argc--;
tlen = lua_objlen( L, -1 );
for( it = 1; it <= tlen; it++ )
{
lua_pushinteger( L, it );
lua_gettable( L, -2 );
lua_insert( L, i );
i++;
argc++;
}
i--;
lua_pop( L, 1 );
}
}
// writes a log message (if needed).
if( check_logcat( "Exec" ) <= settings.log_level )
{
lua_checkstack( L, lua_gettop( L ) + argc * 3 + 2 );
lua_pushvalue( L, 1 );
for( i = 1; i <= argc; i++ )
{
lua_pushstring( L, " [" );
lua_pushvalue( L, i + 1 );
lua_pushstring( L, "]" );
}
lua_concat( L, 3 * argc + 1 );
// replaces midfile 0 chars by linefeed
size_t len = 0;
const char * cs = lua_tolstring( L, -1, &len );
char * s = s_calloc( len + 1, sizeof( char ) );
for( i = 0; i < len; i++ )
{
s[ i ] = cs[ i ] ? cs[ i ] : '\n';
}
logstring0(
LOG_DEBUG, "Exec",
s
);
free( s );
lua_pop( L, 1 );
}
if( argc >= 2 && !strcmp( luaL_checkstring( L, 2 ), "<" ) )
{
// pipes something into stdin
if( !lua_isstring( L, 3 ) )
{
logstring(
"Error",
"in spawn(), expected a string after pipe '<'"
);
safeexit(L, -1 );
}
pipe_text = lua_tolstring( L, 3, &pipe_len );
if( strlen( pipe_text ) > 0 )
{
// creates the pipe
if( pipe( pipefd ) == -1 )
{
logstring( "Error", "cannot create a pipe!" );
safeexit(L, -1 );
}
// always closes the write end for child processes
close_exec_fd( pipefd[ 1 ] );
// sets the write end on non-blocking
non_block_fd( pipefd[ 1 ] );
}
else
{
pipe_text = NULL;
}
argc -= 2;
li += 2;
}
// prepares the arguments
argv = s_calloc( argc + 2, sizeof( char * ) );
argv[ 0 ] = binary;
for( i = 1; i <= argc; i++ )
{
argv[i] = luaL_checkstring( L, i + li );
}
argv[ i ] = NULL;
// the fork!
pid = fork( );
if( pid == 0 )
{
// replaces stdin for pipes
if( pipe_text )
{
dup2( pipefd[ 0 ], STDIN_FILENO );
}
// if lsyncd runs as a daemon and has a logfile it will redirect
// stdout/stderr of child processes to the logfile.
if( is_daemon && settings.log_file )
{
if( !freopen( settings.log_file, "a", stdout ) )
{
printlogf(
L, "Error",
"cannot redirect stdout to '%s'.",
settings.log_file
);
}
if( !freopen( settings.log_file, "a", stderr ) )
{
printlogf(
L, "Error",
"cannot redirect stderr to '%s'.",
settings.log_file
);
}
}
execvp( binary, ( char ** ) argv );
// in a sane world execv does not return!
printlogf(
L, "Error",
"Failed executing [ %s ]!",
binary
);
exit( -1 );
}
if( pipe_text )
{
int len;
// first closes read-end of pipe, this is for child process only
close( pipefd[ 0 ] );
// starts filling the pipe
len = write( pipefd[ 1 ], pipe_text, pipe_len );
if( len < 0 )
{
logstring( "Normal", "immediatly broken pipe." );
close( pipefd[ 1 ] );
}
else if( len == pipe_len )
{
// usual and best case, the pipe accepted all input -> close
close( pipefd[ 1 ] );
logstring( "Exec", "one-sweeped pipe" );
}
else
{
struct pipemsg *pm;
logstring( "Exec", "adding pipe observance" );
pm = s_calloc( 1, sizeof( struct pipemsg ) );
pm->text = s_calloc( pipe_len + 1, sizeof( char ) );
memcpy( pm->text, pipe_text, pipe_len + 1 );
pm->tlen = pipe_len;
pm->pos = len;
observe_fd(
pipefd[ 1 ],
NULL,
pipe_writey,
pipe_tidy,
pm
);
}
}
free( argv );
lua_pushnumber( L, pid );
return 1;
}
/*
| Converts a relative directory path to an absolute.
|
| Params on Lua stack:
| 1: a relative path to directory
|
| Returns on Lua stack:
| The absolute path of directory
*/
static int
l_realdir( lua_State *L )
{
luaL_Buffer b;
const char *rdir = luaL_checkstring(L, 1);
char *adir = get_realpath(rdir);
if( !adir )
{
printlogf(
L, "Error",
"failure getting absolute path of [%s]",
rdir
);
return 0;
}
{
// makes sure its a directory
struct stat st;
if( stat( adir, &st ) )
{
printlogf(
L, "Error",
"cannot get absolute path of dir '%s': %s",
rdir,
strerror( errno )
);
free( adir );
return 0;
}
if( !S_ISDIR( st.st_mode ) )
{
printlogf(
L, "Error",
"cannot get absolute path of dir '%s': is not a directory",
rdir
);
free( adir );
return 0;
}
}
// returns absolute path with a concated '/'
luaL_buffinit( L, &b );
luaL_addstring( &b, adir );
luaL_addchar( &b, '/' );
luaL_pushresult( &b );
free( adir );
return 1;
}
/*
| Dumps the Lua stack.
| For debugging purposes.
*/
int
l_stackdump( lua_State * L )
{
int i;
int top = lua_gettop( L );
printlogf(
L, "Debug",
"total in stack %d",
top
);
for( i = 1; i <= top; i++ )
{
int t = lua_type( L, i );
switch( t )
{
case LUA_TSTRING:
printlogf(
L, "Debug",
"%d string: '%s'",
i, lua_tostring( L, i )
);
break;
case LUA_TBOOLEAN:
printlogf(
L, "Debug",
"%d boolean %s",
i, lua_toboolean( L, i ) ? "true" : "false"
);
break;
case LUA_TNUMBER:
printlogf(
L, "Debug",
"%d number: %g",
i, lua_tonumber( L, i )
);
break;
default:
printlogf(
L, "Debug",
"%d %s",
i, lua_typename( L, t )
);
break;
}
}
return 0;
}
/*
| Reads the directories entries.
|
| Params on Lua stack:
| 1: absolute path to directory
|
| Returns on Lua stack:
| a table of directory names.
| names are keys
| values are boolean true on dirs.
*/
static int
l_readdir( lua_State *L )
{
const char * dirname = luaL_checkstring( L, 1 );
DIR *d;
d = opendir( dirname );
if( d == NULL )
{
printlogf(
L, "Error", "cannot open dir [%s].",
dirname
);
return 0;
}
lua_newtable( L );
while( !hup && !term )
{
struct dirent *de = readdir( d );
bool isdir;
if( de == NULL ) // finished
{
break;
}
// ignores . and ..
if(
!strcmp( de->d_name, "." )
|| !strcmp( de->d_name, ".." )
)
{
continue;
}
if( de->d_type == DT_UNKNOWN )
{
// must call stat on some systems :-/
// ( e.g. ReiserFS )
char *entry = s_malloc(
strlen( dirname ) +
strlen( de->d_name ) +
2
);
struct stat st;
strcpy( entry, dirname );
strcat( entry, "/" );
strcat( entry, de->d_name );
lstat( entry, &st );
isdir = S_ISDIR( st.st_mode );
free( entry );
}
else
{
// otherwise readdir can be trusted
isdir = de->d_type == DT_DIR;
}
// adds this entry to the Lua table
lua_pushstring( L, de->d_name );
lua_pushboolean( L, isdir );
lua_settable( L, -3 );
}
closedir( d );
return 1;
}
/*
| Terminates Lsyncd.
|
| Params on Lua stack:
| 1: exitcode of Lsyncd.
|
| Does not return.
|
*/
int
l_terminate( lua_State *L )
{
int exitcode = luaL_checkinteger( L, 1 );
exit( exitcode );
return 0;
}
/*
| Configures core parameters.
|
| Params on Lua stack:
| 1: a string, configure option
| 2: depends on Param 1
*/
static int
l_configure( lua_State *L )
{
const char * command = luaL_checkstring( L, 1 );
if( !strcmp( command, "running" ) )
{
// set by runner after first initialize
// from this on log to configurated log end instead of
// stdout/stderr
first_time = false;
if( !settings.nodaemon && !settings.log_file )
{
settings.log_syslog = true;
const char * log_ident =
settings.log_ident
? settings.log_ident
: "lsyncd";
openlog( log_ident, 0, settings.log_facility );
}
if( !settings.nodaemon && !is_daemon )
{
logstring( "Normal", "--- Startup, daemonizing ---" );
daemonize( L, settings.pidfile );
}
else
{
logstring( "Normal", "--- Startup ---" );
}
}
else if( !strcmp( command, "nodaemon" ) )
{
settings.nodaemon = true;
}
else if( !strcmp( command, "logfile" ) )
{
const char * file = luaL_checkstring( L, 2 );
if( settings.log_file )
{
free( settings.log_file );
}
settings.log_file =
s_strdup( file );
}
else if( !strcmp( command, "pidfile" ) )
{
const char * file = luaL_checkstring( L, 2 );
if( settings.pidfile )
{
free( settings.pidfile );
}
settings.pidfile = s_strdup( file );
}
else if( !strcmp( command, "logfacility" ) )
{
if( lua_isstring( L, 2 ) )
{
const char * fname = luaL_checkstring( L, 2 );
int i;
for( i = 0; facilitynames[ i ].c_name; i++ )
{
if( !strcasecmp( fname, facilitynames[ i ].c_name ) )
{ break; }
}
if( !facilitynames[ i ].c_name )
{
printlogf(
L, "Error",
"Logging facility '%s' unknown.",
fname
);
exit( -1 );
}
settings.log_facility = facilitynames[ i ].c_val;
}
else if (lua_isnumber(L, 2))
{
settings.log_facility = luaL_checknumber(L, 2);
}
else
{
printlogf(
L, "Error",
"Logging facility must be a number or string"
);
exit( -1 );
}
}
else if( !strcmp( command, "logident" ) )
{
const char * ident = luaL_checkstring( L, 2 );
if( settings.log_ident )
{
free( settings.log_ident );
}
settings.log_ident = s_strdup( ident );
}
else
{
printlogf(
L, "Error",
"Internal error, unknown parameter in l_configure( %s )",
command
);
exit( -1 );
}
return 0;
}
/*
| Allows user scripts to observe filedescriptors
|
| Params on Lua stack:
| 1: file descriptor
| 2: function to call when read becomes ready
| 3: function to call when write becomes ready
*/
static int
l_observe_fd( lua_State *L )
{
int fd = luaL_checknumber( L, 1 );
bool ready = false;
bool writey = false;
// Stores the user function in the lua registry.
// It uses the address of the cores ready/write functions
// for the user as key
if( !lua_isnoneornil( L, 2 ) )
{
lua_pushlightuserdata( L, (void *) user_obs_ready );
lua_gettable( L, LUA_REGISTRYINDEX );
if( lua_isnil( L, -1 ) )
{
lua_pop ( L, 1 );
lua_newtable ( L );
lua_pushlightuserdata ( L, (void *) user_obs_ready );
lua_pushvalue ( L, -2 );
lua_settable ( L, LUA_REGISTRYINDEX );
}
lua_pushnumber ( L, fd );
lua_pushvalue ( L, 2 );
lua_settable ( L, -3 );
lua_pop ( L, 1 );
ready = true;
}
if( !lua_isnoneornil( L, 3 ) )
{
lua_pushlightuserdata( L, (void *) user_obs_writey );
lua_gettable (L, LUA_REGISTRYINDEX );
if( lua_isnil(L, -1) )
{
lua_pop ( L, 1 );
lua_newtable ( L );
lua_pushlightuserdata ( L, (void *) user_obs_writey );
lua_pushvalue ( L, -2 );
lua_settable ( L, LUA_REGISTRYINDEX );
}
lua_pushnumber ( L, fd );
lua_pushvalue ( L, 3 );
lua_settable ( L, -3 );
lua_pop ( L, 1 );
writey = true;
}
// tells the core to watch the fd
observe_fd(
fd,
ready ? user_obs_ready : NULL,
writey ? user_obs_writey : NULL,
user_obs_tidy,
NULL
);
return 0;
}
/*
| Removes a user observance
|
| Params on Lua stack:
| 1: exitcode of Lsyncd.
*/
extern int
l_nonobserve_fd( lua_State *L )
{
int fd = luaL_checknumber( L, 1 );
// removes the read function
lua_pushlightuserdata( L, (void *) user_obs_ready );
lua_gettable( L, LUA_REGISTRYINDEX );
if( !lua_isnil( L, -1 ) )
{
lua_pushnumber ( L, fd );
lua_pushnil ( L );
lua_settable ( L, -2 );
}
lua_pop( L, 1 );
lua_pushlightuserdata( L, (void *) user_obs_writey );
lua_gettable( L, LUA_REGISTRYINDEX );
if ( !lua_isnil( L, -1 ) )
{
lua_pushnumber ( L, fd );
lua_pushnil ( L );
lua_settable ( L, -2 );
}
lua_pop( L, 1 );
nonobserve_fd( fd );
return 0;
}
/*
| Returns file size of given path or nil on error
|
| Params on Lua stack:
| 1: path of filename
*/
extern int
l_file_size( lua_State *L )
{
struct stat sb;
const char *filename = luaL_checkstring( L, 1 );
if (stat(filename, &sb) == -1) {
lua_pushnil(L);
return 1;
}
lua_pushinteger(L, (long long) sb.st_size);
return 1;
}
static int l_jiffies_fromseconds(lua_State *L);
/*
| The Lsnycd's core library
*/
static const luaL_Reg lsyncdlib[] =
{
{ "configure", l_configure },
{ "exec", l_exec },
{ "log", l_log },
{ "now", l_now },
{ "jiffies_from_seconds", l_jiffies_fromseconds},
{ "kill", l_kill },
{ "get_free_port", l_free_port },
{ "nonobserve_fd", l_nonobserve_fd },
{ "observe_fd", l_observe_fd },
{ "readdir", l_readdir },
{ "realdir", l_realdir },
{ "stackdump", l_stackdump },
{ "terminate", l_terminate },
{ "get_file_size", l_file_size },
{ NULL, NULL }
};
/*
| Adds a number in seconds to a jiffy timestamp.
*/
static int
l_jiffies_add( lua_State *L )
{
clock_t *p1 = ( clock_t * ) lua_touserdata( L, 1 );
clock_t *p2 = ( clock_t * ) lua_touserdata( L, 2 );
if( p1 && p2 )
{
logstring( "Error", "Cannot add two timestamps!" );
safeexit(L, -1 );
}
{
clock_t a1 =
p1 ? *p1 : luaL_checknumber( L, 1 ) * clocks_per_sec;
clock_t a2 =
p2 ? *p2 : luaL_checknumber( L, 2 ) * clocks_per_sec;
clock_t *r =
( clock_t * ) lua_newuserdata( L, sizeof( clock_t ) );
luaL_getmetatable( L, "Lsyncd.jiffies" );
lua_setmetatable( L, -2 );
*r = a1 + a2;
return 1;
}
}
/*
| Adds a number in seconds to a jiffy timestamp.
*/
static int
l_jiffies_concat( lua_State *L )
{
char buf[1024];
clock_t *p1 = ( clock_t * ) lua_touserdata( L, 1 );
clock_t *p2 = ( clock_t * ) lua_touserdata( L, 2 );
if( p1 && p2 )
{
logstring( "Error", "Cannot add two timestamps!" );
safeexit(L, -1 );
}
{
if (p1) {
snprintf( buf, sizeof(buf), "%Lf", (long double)(*p1));
lua_pushfstring(L, "%s%s", &buf, luaL_checkstring( L, 2));
} else {
snprintf( buf, sizeof(buf), "%Lf", (long double)(*p2));
lua_pushfstring(L, "%s%s", luaL_checkstring( L, 1), &buf);
}
return 1;
}
}
/*
| Subracts two jiffy timestamps resulting in a number in seconds
| or substracts a jiffy by a number in seconds resulting a jiffy timestamp.
*/
static int
l_jiffies_sub( lua_State *L )
{
clock_t *p1 = ( clock_t * ) lua_touserdata( L, 1 );
clock_t *p2 = ( clock_t * ) lua_touserdata( L, 2 );
if( p1 && p2 )
{
// substracting two timestamps result in a timespan in seconds
clock_t a1 = *p1;
clock_t a2 = *p2;
lua_pushnumber(L, ((double) (a1 -a2)) / clocks_per_sec);
return 1;
}
// makes a timestamp earlier by NUMBER seconds
clock_t a1 = p1 ? *p1 : luaL_checknumber( L, 1 ) * clocks_per_sec;
clock_t a2 = p2 ? *p2 : luaL_checknumber( L, 2 ) * clocks_per_sec;
clock_t *r = (clock_t *) lua_newuserdata( L, sizeof( clock_t ) );
luaL_getmetatable( L, "Lsyncd.jiffies" );
lua_setmetatable( L, -2 );
*r = a1 - a2;
return 1;
}
/*
| Compares two jiffy timestamps
*/
static int
l_jiffies_eq( lua_State *L )
{
clock_t a1 = ( *( clock_t * ) luaL_checkudata( L, 1, "Lsyncd.jiffies" ) );
clock_t a2 = ( *( clock_t * ) luaL_checkudata( L, 2, "Lsyncd.jiffies" ) );
lua_pushboolean( L, a1 == a2 );
return 1;
}
/*
* True if jiffy1 timestamp is eariler than jiffy2 timestamp
*/
static int
l_jiffies_lt( lua_State *L )
{
clock_t a1 = ( *( clock_t * ) luaL_checkudata( L, 1, "Lsyncd.jiffies" ) );
clock_t a2 = ( *( clock_t * ) luaL_checkudata( L, 2, "Lsyncd.jiffies" ) );
lua_pushboolean( L, time_before( a1, a2 ) );
return 1;
}
/*
| True if jiffy1 before or equals jiffy2
*/
static int
l_jiffies_le(lua_State *L)
{
clock_t a1 = ( *( clock_t * ) luaL_checkudata( L, 1, "Lsyncd.jiffies" ) );
clock_t a2 = ( *( clock_t * ) luaL_checkudata( L, 2, "Lsyncd.jiffies" ) );
lua_pushboolean( L, ( a1 == a2 ) || time_before( a1, a2 ) );
return 1;
}
/*
| Converts a jiffies to a number
*/
static int
l_jiffies_tonumber(lua_State *L)
{
clock_t a1 = ( *( clock_t * ) luaL_checkudata( L, 1, "Lsyncd.jiffies" ) );
lua_pushinteger( L, a1 * clocks_per_sec);
return 1;
}
/*
| Converts a jiffies to a number
*/
static int
l_jiffies_fromseconds(lua_State *L)
{
lua_Integer a1 = luaL_checkinteger(L, 1);
clock_t *r = (clock_t *) lua_newuserdata( L, sizeof( clock_t ) );
luaL_getmetatable( L, "Lsyncd.jiffies" );
lua_setmetatable( L, -2 );
*r = a1 * clocks_per_sec;
return 1;
}
/*
| Converts a jiffies to a number
*/
static int
l_jiffies_index(lua_State *L)
{
clock_t a1 = ( *( clock_t * ) luaL_checkudata( L, 1, "Lsyncd.jiffies" ) );
const char *a2 = luaL_checkstring(L, 2);
if (!strcmp(a2, "seconds")) {
lua_pushinteger( L, a1 / clocks_per_sec);
return 1;
} else if (!strcmp(a2, "string")) {
lua_pushfstring (L, "%d", a1 / clocks_per_sec);
return 1;
}
return 0;
}
/*
| Registers the Lsyncd's core library.
*/
void
register_lsyncd( lua_State *L )
{
lua_compat_register( L, LSYNCD_LIBNAME, lsyncdlib );
lua_setglobal( L, LSYNCD_LIBNAME );
// creates the metatable for the jiffies ( timestamps ) userdata
luaL_newmetatable( L, "Lsyncd.jiffies" );
int mt = lua_gettop( L );
lua_pushcfunction( L, l_jiffies_add );
lua_setfield( L, mt, "__add" );
lua_pushcfunction( L, l_jiffies_sub );
lua_setfield( L, mt, "__sub" );
lua_pushcfunction( L, l_jiffies_lt );
lua_setfield( L, mt, "__lt" );
lua_pushcfunction( L, l_jiffies_le );
lua_setfield( L, mt, "__le" );
lua_pushcfunction( L, l_jiffies_eq );
lua_setfield( L, mt, "__eq" );
lua_pushcfunction( L, l_jiffies_concat );
lua_setfield( L, mt, "__concat" );
lua_pushcfunction( L, l_jiffies_index );
lua_setfield( L, mt, "__index" );
lua_pop( L, 1 ); // pop(mt)
#ifdef WITH_INOTIFY
lua_getglobal( L, LSYNCD_LIBNAME );
register_inotify( L );
lua_setfield( L, -2, LSYNCD_INOTIFYLIBNAME );
lua_pop( L, 1 );
#endif
if( lua_gettop( L ) )
{
logstring(
"Error",
"internal, stack not empty in lsyncd_register( )"
);
exit( -1 );
}
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*
( Lsyncd Core )
*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
/*
| Pushes a function from the runner on the stack.
| As well as the callError handler.
*/
extern void
load_runner_func(
lua_State * L,
const char * name
)
{
printlogf( L, "Call", "%s( )", name );
// pushes the error handler
lua_pushlightuserdata( L, (void *) &callError );
lua_gettable( L, LUA_REGISTRYINDEX );
// pushes the function
lua_pushlightuserdata( L, (void *) &runner );
lua_gettable( L, LUA_REGISTRYINDEX );
lua_pushstring( L, name );
lua_gettable( L, -2 );
lua_remove( L, -2 );
}
/*
| Daemonizes.
|
| Lsyncds own implementation over daemon(0, 0) since
| a) OSX keeps bugging about it being deprecated
| b) for a reason, since blindly closing stdin/out/err
| is unsafe, since they might not have existed and
| might actually close the monitors fd!
*/
static void
daemonize(
lua_State *L, // the lua state
const char *pidfile // if not NULL write pidfile
)
{
pid_t pid, sid;
pid = fork( );
if( pid < 0 )
{
printlogf(
L, "Error",
"Failure in daemonize at fork: %s",
strerror( errno )
);
exit( -1 );
}
if( pid > 0 )
{
// parent process returns to shell
exit( 0 );
}
if( pidfile )
{
write_pidfile( L, pidfile );
}
// detaches the new process from the parent process
sid = setsid( );
if( sid < 0 )
{
printlogf(
L, "Error",
"Failure in daemonize at setsid: %s",
strerror( errno )
);
exit( -1 );
}
// goes to root dir
if( chdir( "/" ) < 0 )
{
printlogf(
L, "Error",
"Failure in daemonize at chdir( \"/\" ): %s",
strerror( errno )
);
exit( -1 );
}
// does what clibs daemon( 0, 0 ) cannot do,
// checks if there were no stdstreams and it might close used fds
if( observances_len && observances->fd < 3 )
{
printlogf(
L, "Normal",
"daemonize not closing stdin/out/err, since there seem to none."
);
return;
}
// disconnects stdstreams
if (
!freopen( "/dev/null", "r", stdin ) ||
!freopen( "/dev/null", "w", stdout ) ||
!freopen( "/dev/null", "w", stderr )
)
{
printlogf(
L, "Error",
"Failure in daemonize at freopen( /dev/null, std[in|out|err] )"
);
}
is_daemon = true;
}
/*
| Normal operation happens in here.
*/
static void
masterloop(lua_State *L)
{
while( true )
{
bool have_alarm;
bool force_alarm = false;
clock_t now = times( dummy_tms );
clock_t alarm_time = 0;
// memory usage debugging
// lua_gc( L, LUA_GCCOLLECT, 0 );
// printf(
// "gccount: %d\n",
// lua_gc( L, LUA_GCCOUNT, 0 ) * 1024 + lua_gc( L, LUA_GCCOUNTB, 0 ) );
//
// queries the runner about the soonest alarm
//
load_runner_func( L, "getAlarm" );
if( lua_pcall( L, 0, 1, -2 ) )
{
safeexit(L, -1 );
}
if( lua_type( L, -1 ) == LUA_TBOOLEAN)
{
have_alarm = false;
force_alarm = lua_toboolean( L, -1 );
}
else
{
have_alarm = true;
alarm_time = *( ( clock_t * ) luaL_checkudata( L, -1, "Lsyncd.jiffies" ) );
}
lua_pop( L, 2 );
if(
force_alarm ||
( have_alarm && time_before_eq( alarm_time, now ) )
)
{
// there is a delay that wants to be handled already thus instead
// of reading/writing from observances it jumps directly to
// handling
// TODO: Actually it might be smarter to handler observances
// eitherway. since event queues might overflow.
logstring( "Masterloop", "immediately handling delays." );
}
else
{
// uses select( ) to determine what happens next:
// a) a new event on an observance
// b) an alarm on timeout
// c) the return of a child process
struct timespec tv;
if( have_alarm )
{
// TODO use trunc instead of long converstions
double d = ( (double )( alarm_time - now ) ) / clocks_per_sec;
tv.tv_sec = d;
tv.tv_nsec = ( (d - ( long ) d) ) * 1000000000.0;
printlogf(
L, "Masterloop",
"going into select ( timeout %f seconds )",
d
);
}
else
{
logstring(
"Masterloop",
"going into select ( no timeout )"
);
}
// time for Lsyncd to try to put itself to rest into the big select( )
// this configures:
// timeouts,
// filedescriptors and
// signals
// that will wake Lsyncd
{
fd_set rfds;
fd_set wfds;
sigset_t sigset;
int pi, pr;
sigemptyset( &sigset );
FD_ZERO( &rfds );
FD_ZERO( &wfds );
for( pi = 0; pi < observances_len; pi++ )
{
struct observance *obs = observances + pi;
if ( obs->ready )
{
FD_SET( obs->fd, &rfds );
}
if ( obs->writey )
{
FD_SET( obs->fd, &wfds );
}
}
if( !observances_len )
{
logstring(
"Error",
"Internal fail, no observances, no monitor!"
);
exit( -1 );
}
// the great select, this is the very heart beat of Lsyncd
// that puts Lsyncd to sleep until anything worth noticing
// happens
pr = pselect(
observances[ observances_len - 1 ].fd + 1,
&rfds,
&wfds,
NULL,
have_alarm ? &tv : NULL,
&sigset
);
// something happened!
if (pr >= 0)
{
// walks through the observances calling ready/writey
observance_action = true;
for( pi = 0; pi < observances_len; pi++ )
{
struct observance *obs = observances + pi;
// Checks for signals
if( hup || term )
{
break;
}
// a file descriptor became read-ready
if( obs->ready && FD_ISSET( obs->fd, &rfds ) )
{
obs->ready(L, obs);
}
// Checks for signals, again, better safe than sorry
if ( hup || term )
{
break;
}
// FIXME breaks on multiple nonobservances in one beat
if(
nonobservances_len > 0 &&
nonobservances[ nonobservances_len - 1 ] == obs->fd
)
{
continue;
}
// a file descriptor became write-ready
if( obs->writey && FD_ISSET( obs->fd, &wfds ) )
{
obs->writey( L, obs );
}
}
observance_action = false;
// works through delayed nonobserve_fd() calls
for (pi = 0; pi < nonobservances_len; pi++)
{
nonobserve_fd( nonobservances[ pi ] );
}
nonobservances_len = 0;
}
}
}
// collects zombified child processes
while( 1 )
{
int status;
pid_t pid = waitpid( 0, &status, WNOHANG );
if (pid <= 0)
{
// no more zombies
break;
}
// calls the runner to handle the collection
load_runner_func( L, "collectProcess" );
lua_pushinteger( L, pid );
lua_pushinteger( L, WEXITSTATUS( status ) );
if ( lua_pcall( L, 2, 0, -4 ) )
{
safeexit(L, -1);
}
lua_pop( L, 1 );
}
// reacts on HUP signals
if( hup )
{
load_runner_func( L, "hup" );
if( lua_pcall( L, 0, 0, -2 ) )
{
safeexit( L, -1 );
}
lua_pop( L, 1 );
hup = 0;
}
// reacts on TERM and INT signals
if( term == 1 )
{
load_runner_func( L, "term" );
lua_pushnumber( L, sigcode );
if( lua_pcall( L, 1, 0, -3 ) )
{
safeexit(L, -1 );
}
lua_pop( L, 1 );
term = 2;
}
// lets the runner do stuff every cycle,
// like starting new processes, writing the statusfile etc.
load_runner_func( L, "cycle" );
l_now( L );
if( lua_pcall( L, 1, 1, -3 ) )
{
safeexit(L, -1 );
}
if( !lua_toboolean( L, -1 ) )
{
// cycle told core to break mainloop
lua_pop( L, 2 );
return;
}
lua_pop( L, 2 );
if( lua_gettop( L ) )
{
logstring(
"Error",
"internal, stack is dirty."
);
l_stackdump( L );
safeexit(L, -1 );
}
}
}
/*
| The effective main for one run.
|
| HUP signals may cause several runs of the one main.
*/
int
main1( int argc, char *argv[] )
{
// the Lua interpreter
lua_State * L;
// the runner file
char * lsyncd_runner_file = NULL;
int argp = 1;
// load Lua
L = luaL_newstate( );
luaL_openlibs( L );
{
// checks the lua version
const char * version;
int major, minor;
lua_getglobal( L, "_VERSION" );
version = luaL_checkstring( L, -1 );
if(
sscanf(
version,
"Lua %d.%d",
&major, &minor
) != 2
)
{
fprintf(
stderr,
"cannot parse lua library version!\n"
);
exit (-1 );
}
if(
major < 5 ||
(major == 5 && minor < 1)
) {
fprintf(
stderr,
"Lua library is too old. Needs 5.1 at least"
);
exit( -1 );
}
lua_pop( L, 1 );
}
{
// logging is prepared quite early
int i = 1;
add_logcat( "Normal", LOG_NOTICE );
add_logcat( "Warn", LOG_WARNING );
add_logcat( "Error", LOG_ERR );
while( i < argc )
{
if(
strcmp( argv[ i ], "-log" ) &&
strcmp( argv[ i ], "--log" )
)
{
// arg is neither -log or --log
i++;
continue;
}
if( ++i >= argc )
{
// -(-)log was last argument
break;
}
if( !add_logcat( argv[ i ], LOG_NOTICE ) )
{
printlogf(
L, "Error",
"'%s' is not a valid logging category",
argv[ i ]
);
exit( -1 );
}
}
}
// registers Lsycnd's core library
register_lsyncd( L );
if( check_logcat( "Debug" ) <= settings.log_level )
{
// printlogf doesnt support %ld :-(
printf(
"kernels clocks_per_sec=%ld\n",
clocks_per_sec
);
}
// checks if the user overrode the default runner file
if(
argp < argc &&
!strcmp( argv[ argp ], "--runner" )
)
{
if (argp + 1 >= argc)
{
logstring(
"Error",
"Lsyncd Lua-runner file missing after --runner "
);
exit( -1 );
}
lsyncd_runner_file = argv[ argp + 1 ];
argp += 2;
}
if( lsyncd_runner_file )
{
// checks if the runner file exists
struct stat st;
if( stat( lsyncd_runner_file, &st ) )
{
printlogf(
L, "Error",
"Cannot see a runner at '%s'.",
lsyncd_runner_file
);
exit( -1 );
}
// loads the runner file
if( luaL_loadfile(L, lsyncd_runner_file ) )
{
printlogf(
L, "Error",
"error loading '%s': %s",
lsyncd_runner_file,
lua_tostring( L, -1 )
);
exit( -1 );
}
}
else
{
// loads the runner from binary
if( luaL_loadbuffer( L, runner_out, runner_size, "runner" ) )
{
printlogf(
L, "Error",
"error loading precompiled runner: %s",
lua_tostring( L, -1 )
);
exit( -1 );
}
}
// prepares the runner executing the script
{
if( lua_pcall( L, 0, LUA_MULTRET, 0 ) )
{
printlogf(
L, "Error",
"preparing runner: %s",
lua_tostring( L, -1 )
);
exit( -1 );
}
lua_pushlightuserdata( L, (void *) & runner );
// switches the value ( result of preparing ) and the key &runner
lua_insert( L, 1 );
// saves the table of the runners functions in the lua registry
lua_settable( L, LUA_REGISTRYINDEX );
// saves the error function extras
// &callError is the key
lua_pushlightuserdata ( L, (void *) &callError );
// &runner[ callError ] the value
lua_pushlightuserdata ( L, (void *) &runner );
lua_gettable ( L, LUA_REGISTRYINDEX );
lua_pushstring ( L, "callError" );
lua_gettable ( L, -2 );
lua_remove ( L, -2 );
lua_settable ( L, LUA_REGISTRYINDEX );
}
// asserts the Lsyncd's version matches
// between runner and core
{
const char *lversion;
lua_getglobal( L, "lsyncd_version" );
lversion = luaL_checkstring( L, -1 );
if( strcmp( lversion, PACKAGE_VERSION ) )
{
printlogf(
L, "Error",
"Version mismatch '%s' is '%s', but core is '%s'",
lsyncd_runner_file ? lsyncd_runner_file : "( internal runner )",
lversion, PACKAGE_VERSION
);
exit( -1 );
}
lua_pop( L, 1 );
}
// loads the defaults from binary
{
if( luaL_loadbuffer( L, defaults_out, defaults_size, "defaults" ) )
{
printlogf(
L, "Error",
"loading defaults: %s",
lua_tostring( L, -1 )
);
exit( -1 );
}
// prepares the defaults
if( lua_pcall( L, 0, 0, 0 ) )
{
printlogf(
L, "Error",
"preparing defaults: %s",
lua_tostring( L, -1 )
);
exit( -1 );
}
}
// checks if there is a "-help" or "--help"
{
int i;
for( i = argp; i < argc; i++ )
{
if (
!strcmp( argv[ i ], "-help" ) ||
!strcmp( argv[ i ], "--help" )
)
{
load_runner_func( L, "help" );
if( lua_pcall( L, 0, 0, -2 ) )
{
exit( -1 );
}
lua_pop( L, 1 );
exit( 0 );
}
}
}
// starts the option parser in Lua script
{
int idx = 1;
const char *s;
// creates a table with all remaining argv option arguments
load_runner_func( L, "configure" );
lua_newtable( L );
while( argp < argc )
{
lua_pushnumber ( L, idx++ );
lua_pushstring ( L, argv[ argp++ ] );
lua_settable ( L, -3 );
}
// creates a table with the cores event monitor interfaces
idx = 0;
lua_newtable( L );
while( monitors[ idx ] )
{
lua_pushnumber ( L, idx + 1 );
lua_pushstring ( L, monitors[ idx++ ] );
lua_settable ( L, -3 );
}
if( lua_pcall( L, 2, 1, -4 ) )
{
exit( -1 );
}
if( first_time )
{
// If not first time, simply retains the config file given
s = lua_tostring(L, -1);
if( s )
{
lsyncd_config_file = s_strdup( s );
}
}
lua_pop( L, 2 );
}
// checks existence of the config file
if( lsyncd_config_file )
{
struct stat st;
// gets the absolute path to the config file
// so in case of HUPing the daemon, it finds it again
char * apath = get_realpath( lsyncd_config_file );
if( !apath )
{
printlogf(
L, "Error",
"Cannot find config file at '%s'.",
lsyncd_config_file
);
exit( -1 );
}
free( lsyncd_config_file );
lsyncd_config_file = apath;
if( stat( lsyncd_config_file, &st ) )
{
printlogf(
L, "Error",
"Cannot find config file at '%s'.",
lsyncd_config_file
);
exit( -1 );
}
// loads and executes the config file
if( luaL_loadfile( L, lsyncd_config_file ) )
{
printlogf(
L, "Error",
"error loading %s: %s",
lsyncd_config_file,
lua_tostring( L, -1 )
);
exit( -1 );
}
if( lua_pcall( L, 0, LUA_MULTRET, 0) )
{
printlogf(
L, "Error",
"error preparing %s: %s",
lsyncd_config_file,
lua_tostring( L, -1 )
);
l_traceback(L);
safeexit(L, -1 );
}
}
#ifdef WITH_INOTIFY
open_inotify( L );
#endif
#ifdef WITH_FSEVENTS
open_fsevents( L );
#endif
// adds signal handlers
// listens to SIGCHLD, but blocks it until pselect( )
// opens the signal handler up
{
sigset_t set;
sigemptyset( &set );
sigaddset( &set, SIGCHLD );
signal( SIGCHLD, sig_child );
sigprocmask( SIG_BLOCK, &set, NULL );
signal( SIGHUP, sig_handler );
signal( SIGTERM, sig_handler );
signal( SIGINT, sig_handler );
}
// runs initializations from runner
// it will set the configuration and add watches
{
load_runner_func( L, "initialize" );
lua_pushboolean( L, first_time );
if( lua_pcall( L, 1, 0, -3 ) )
{
exit( -1 );
}
lua_pop( L, 1 );
}
//
// enters the master loop
//
masterloop( L );
//
// cleanup
//
// tidies up all observances
{
int i;
for( i = 0; i < observances_len; i++ )
{
struct observance *obs = observances + i;
obs->tidy( obs );
}
observances_len = 0;
nonobservances_len = 0;
}
// frees logging categories
{
int ci;
struct logcat *lc;
for( ci = 'A'; ci <= 'Z'; ci++ )
{
for( lc = logcats[ ci - 'A' ]; lc && lc->name; lc++)
{
free( lc->name );
lc->name = NULL;
}
if( logcats[ci - 'A' ] )
{
free( logcats[ ci - 'A' ] );
logcats[ ci - 'A' ] = NULL;
}
}
}
lua_close( L );
return 0;
}
/*
| Main
*/
int
main( int argc, char * argv[ ] )
{
// gets a kernel parameter
clocks_per_sec = sysconf( _SC_CLK_TCK );
setlinebuf( stdout );
setlinebuf( stderr );
while( !term ) {
main1( argc, argv );
}
if( pidfile_fd > 0 )
{
close( pidfile_fd );
}
if( settings.pidfile )
{
remove( settings.pidfile );
}
// exits with error code responding to the signal it died for
return 128 + sigcode;
}
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