samba-mirror/ctdb/common/ctdb_util.c

/* 
   ctdb utility code

   Copyright (C) Andrew Tridgell  2006

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "tdb.h"
#include "system/network.h"
#include "system/filesys.h"
#include "system/wait.h"
#include "system/shmem.h"
#include "../include/ctdb_private.h"

/*
  return error string for last error
*/
const char *ctdb_errstr(struct ctdb_context *ctdb)
{
	return ctdb->err_msg;
}


/*
  remember an error message
*/
void ctdb_set_error(struct ctdb_context *ctdb, const char *fmt, ...)
{
	va_list ap;
	talloc_free(ctdb->err_msg);
	va_start(ap, fmt);
	ctdb->err_msg = talloc_vasprintf(ctdb, fmt, ap);
	DEBUG(DEBUG_ERR,("ctdb error: %s\n", ctdb->err_msg));
	va_end(ap);
}

/*
  a fatal internal error occurred - no hope for recovery
*/
void ctdb_fatal(struct ctdb_context *ctdb, const char *msg)
{
	DEBUG(DEBUG_ALERT,("ctdb fatal error: %s\n", msg));
	abort();
}

/*
  like ctdb_fatal() but a core/backtrace would not be useful
*/
void ctdb_die(struct ctdb_context *ctdb, const char *msg)
{
	DEBUG(DEBUG_ALERT,("ctdb exiting with error: %s\n", msg));
	exit(1);
}

/* Invoke an external program to do some sort of tracing on the CTDB
 * process.  This might block for a little while.  The external
 * program is specified by the environment variable
 * CTDB_EXTERNAL_TRACE.  This program should take one argument: the
 * pid of the process to trace.  Commonly, the program would be a
 * wrapper script around gcore.
 */
void ctdb_external_trace(void)
{

	const char * t = getenv("CTDB_EXTERNAL_TRACE");
	char * cmd;

	if (t == NULL) {
		return;
	}

	cmd = talloc_asprintf(NULL, "%s %lu", t, (unsigned long) getpid());
	DEBUG(DEBUG_WARNING,("begin external trace: %s\n", cmd));
	system(cmd);
	DEBUG(DEBUG_WARNING,("end external trace: %s\n", cmd));
	talloc_free(cmd);
}

/*
  parse a IP:port pair
*/
int ctdb_parse_address(struct ctdb_context *ctdb,
		       TALLOC_CTX *mem_ctx, const char *str,
		       struct ctdb_address *address)
{
	struct servent *se;

	setservent(0);
	se = getservbyname("ctdb", "tcp");
	endservent();
	
	address->address = talloc_strdup(mem_ctx, str);
	CTDB_NO_MEMORY(ctdb, address->address);

	if (se == NULL) {
		address->port = CTDB_PORT;
	} else {
		address->port = ntohs(se->s_port);
	}
	return 0;
}


/*
  check if two addresses are the same
*/
bool ctdb_same_address(struct ctdb_address *a1, struct ctdb_address *a2)
{
	return strcmp(a1->address, a2->address) == 0 && a1->port == a2->port;
}


/*
  hash function for mapping data to a VNN - taken from tdb
*/
uint32_t ctdb_hash(const TDB_DATA *key)
{
	return tdb_jenkins_hash(discard_const(key));
}

/*
  a type checking varient of idr_find
 */
static void *_idr_find_type(struct idr_context *idp, int id, const char *type, const char *location)
{
	void *p = idr_find(idp, id);
	if (p && talloc_check_name(p, type) == NULL) {
		DEBUG(DEBUG_ERR,("%s idr_find_type expected type %s  but got %s\n",
			 location, type, talloc_get_name(p)));
		return NULL;
	}
	return p;
}

uint32_t ctdb_reqid_new(struct ctdb_context *ctdb, void *state)
{
	int id = idr_get_new_above(ctdb->idr, state, ctdb->lastid+1, INT_MAX);
	if (id < 0) {
		DEBUG(DEBUG_DEBUG, ("Reqid wrap!\n"));
		id = idr_get_new(ctdb->idr, state, INT_MAX);
	}
	ctdb->lastid = id;
	return id;
}

void *_ctdb_reqid_find(struct ctdb_context *ctdb, uint32_t reqid, const char *type, const char *location)
{
	void *p;

	p = _idr_find_type(ctdb->idr, reqid, type, location);
	if (p == NULL) {
		DEBUG(DEBUG_WARNING, ("Could not find idr:%u\n",reqid));
	}

	return p;
}


void ctdb_reqid_remove(struct ctdb_context *ctdb, uint32_t reqid)
{
	int ret;

	ret = idr_remove(ctdb->idr, reqid);
	if (ret != 0) {
		DEBUG(DEBUG_ERR, ("Removing idr that does not exist\n"));
	}
}


/*
  form a ctdb_rec_data record from a key/data pair
  
  note that header may be NULL. If not NULL then it is included in the data portion
  of the record
 */
struct ctdb_rec_data *ctdb_marshall_record(TALLOC_CTX *mem_ctx, uint32_t reqid,	
					   TDB_DATA key, 
					   struct ctdb_ltdb_header *header,
					   TDB_DATA data)
{
	size_t length;
	struct ctdb_rec_data *d;

	length = offsetof(struct ctdb_rec_data, data) + key.dsize + 
		data.dsize + (header?sizeof(*header):0);
	d = (struct ctdb_rec_data *)talloc_size(mem_ctx, length);
	if (d == NULL) {
		return NULL;
	}
	d->length = length;
	d->reqid = reqid;
	d->keylen = key.dsize;
	memcpy(&d->data[0], key.dptr, key.dsize);
	if (header) {
		d->datalen = data.dsize + sizeof(*header);
		memcpy(&d->data[key.dsize], header, sizeof(*header));
		memcpy(&d->data[key.dsize+sizeof(*header)], data.dptr, data.dsize);
	} else {
		d->datalen = data.dsize;
		memcpy(&d->data[key.dsize], data.dptr, data.dsize);
	}
	return d;
}


/* helper function for marshalling multiple records */
struct ctdb_marshall_buffer *ctdb_marshall_add(TALLOC_CTX *mem_ctx, 
					       struct ctdb_marshall_buffer *m,
					       uint64_t db_id,
					       uint32_t reqid,
					       TDB_DATA key,
					       struct ctdb_ltdb_header *header,
					       TDB_DATA data)
{
	struct ctdb_rec_data *r;
	size_t m_size, r_size;
	struct ctdb_marshall_buffer *m2;

	r = ctdb_marshall_record(mem_ctx, reqid, key, header, data);
	if (r == NULL) {
		talloc_free(m);
		return NULL;
	}

	if (m == NULL) {
		m = talloc_zero_size(mem_ctx, offsetof(struct ctdb_marshall_buffer, data));
		if (m == NULL) {
			return NULL;
		}
		m->db_id = db_id;
	}

	m_size = talloc_get_size(m);
	r_size = talloc_get_size(r);

	m2 = talloc_realloc_size(mem_ctx, m,  m_size + r_size);
	if (m2 == NULL) {
		talloc_free(m);
		return NULL;
	}

	memcpy(m_size + (uint8_t *)m2, r, r_size);

	talloc_free(r);

	m2->count++;

	return m2;
}

/* we've finished marshalling, return a data blob with the marshalled records */
TDB_DATA ctdb_marshall_finish(struct ctdb_marshall_buffer *m)
{
	TDB_DATA data;
	data.dptr = (uint8_t *)m;
	data.dsize = talloc_get_size(m);
	return data;
}

/* 
   loop over a marshalling buffer 
   
     - pass r==NULL to start
     - loop the number of times indicated by m->count
*/
struct ctdb_rec_data *ctdb_marshall_loop_next(struct ctdb_marshall_buffer *m, struct ctdb_rec_data *r,
					      uint32_t *reqid,
					      struct ctdb_ltdb_header *header,
					      TDB_DATA *key, TDB_DATA *data)
{
	if (r == NULL) {
		r = (struct ctdb_rec_data *)&m->data[0];
	} else {
		r = (struct ctdb_rec_data *)(r->length + (uint8_t *)r);
	}

	if (reqid != NULL) {
		*reqid = r->reqid;
	}
	
	if (key != NULL) {
		key->dptr   = &r->data[0];
		key->dsize  = r->keylen;
	}
	if (data != NULL) {
		data->dptr  = &r->data[r->keylen];
		data->dsize = r->datalen;
		if (header != NULL) {
			data->dptr += sizeof(*header);
			data->dsize -= sizeof(*header);
		}
	}

	if (header != NULL) {
		if (r->datalen < sizeof(*header)) {
			return NULL;
		}
		*header = *(struct ctdb_ltdb_header *)&r->data[r->keylen];
	}

	return r;
}

/*
   This is used to canonicalize a ctdb_sock_addr structure.
*/
void ctdb_canonicalize_ip(const ctdb_sock_addr *ip, ctdb_sock_addr *cip)
{
	char prefix[12] = { 0,0,0,0,0,0,0,0,0,0,0xff,0xff };

	memcpy(cip, ip, sizeof (*cip));

	if ( (ip->sa.sa_family == AF_INET6)
	&& !memcmp(&ip->ip6.sin6_addr, prefix, 12)) {
		memset(cip, 0, sizeof(*cip));
#ifdef HAVE_SOCK_SIN_LEN
		cip->ip.sin_len = sizeof(*cip);
#endif
		cip->ip.sin_family = AF_INET;
		cip->ip.sin_port   = ip->ip6.sin6_port;
		memcpy(&cip->ip.sin_addr, &ip->ip6.sin6_addr.s6_addr[12], 4);
	}
}

bool ctdb_same_ip(const ctdb_sock_addr *tip1, const ctdb_sock_addr *tip2)
{
	ctdb_sock_addr ip1, ip2;

	ctdb_canonicalize_ip(tip1, &ip1);
	ctdb_canonicalize_ip(tip2, &ip2);
	
	if (ip1.sa.sa_family != ip2.sa.sa_family) {
		return false;
	}

	switch (ip1.sa.sa_family) {
	case AF_INET:
		return ip1.ip.sin_addr.s_addr == ip2.ip.sin_addr.s_addr;
	case AF_INET6:
		return !memcmp(&ip1.ip6.sin6_addr.s6_addr[0],
				&ip2.ip6.sin6_addr.s6_addr[0],
				16);
	default:
		DEBUG(DEBUG_ERR, (__location__ " CRITICAL Can not compare sockaddr structures of type %u\n", ip1.sa.sa_family));
		return false;
	}

	return true;
}

/*
  compare two ctdb_sock_addr structures
 */
bool ctdb_same_sockaddr(const ctdb_sock_addr *ip1, const ctdb_sock_addr *ip2)
{
	return ctdb_same_ip(ip1, ip2) && ip1->ip.sin_port == ip2->ip.sin_port;
}

char *ctdb_addr_to_str(ctdb_sock_addr *addr)
{
	static char cip[128] = "";

	switch (addr->sa.sa_family) {
	case AF_INET:
		inet_ntop(addr->ip.sin_family, &addr->ip.sin_addr, cip, sizeof(cip));
		break;
	case AF_INET6:
		inet_ntop(addr->ip6.sin6_family, &addr->ip6.sin6_addr, cip, sizeof(cip));
		break;
	default:
		DEBUG(DEBUG_ERR, (__location__ " ERROR, unknown family %u\n", addr->sa.sa_family));
		ctdb_external_trace();
	}

	return cip;
}

unsigned ctdb_addr_to_port(ctdb_sock_addr *addr)
{
	switch (addr->sa.sa_family) {
	case AF_INET:
		return ntohs(addr->ip.sin_port);
		break;
	case AF_INET6:
		return ntohs(addr->ip6.sin6_port);
		break;
	default:
		DEBUG(DEBUG_ERR, (__location__ " ERROR, unknown family %u\n", addr->sa.sa_family));
	}

	return 0;
}

/* we don't lock future pages here; it would increase the chance that
 * we'd fail to mmap later on. */
void lockdown_memory(bool valgrinding)
{
#if defined(HAVE_MLOCKALL) && !defined(_AIX_)
	/* Extra stack, please! */
	char dummy[10000];
	memset(dummy, 0, sizeof(dummy));

	if (valgrinding) {
		return;
	}

	/* Ignore when running in local daemons mode */
	if (getuid() != 0) {
		return;
	}

	/* Avoid compiler optimizing out dummy. */
	mlock(dummy, sizeof(dummy));
	if (mlockall(MCL_CURRENT) != 0) {
		DEBUG(DEBUG_WARNING,("Failed to lockdown memory: %s'\n",
				     strerror(errno)));
	}
#endif
}

const char *ctdb_eventscript_call_names[] = {
	"init",
	"setup",
	"startup",
	"startrecovery",
	"recovered",
	"takeip",
	"releaseip",
	"stopped",
	"monitor",
	"status",
	"shutdown",
	"reload",
	"updateip",
	"ipreallocated"
};

/* Runstate handling */
static struct {
	enum ctdb_runstate runstate;
	const char * label;
} runstate_map[] = {
	{ CTDB_RUNSTATE_UNKNOWN, "UNKNOWN" },
	{ CTDB_RUNSTATE_INIT, "INIT" },
	{ CTDB_RUNSTATE_SETUP, "SETUP" },
	{ CTDB_RUNSTATE_FIRST_RECOVERY, "FIRST_RECOVERY" },
	{ CTDB_RUNSTATE_STARTUP, "STARTUP" },
	{ CTDB_RUNSTATE_RUNNING, "RUNNING" },
	{ CTDB_RUNSTATE_SHUTDOWN, "SHUTDOWN" },
	{ -1, NULL },
};

const char *runstate_to_string(enum ctdb_runstate runstate)
{
	int i;
	for (i=0; runstate_map[i].label != NULL ; i++) {
		if (runstate_map[i].runstate == runstate) {
			return runstate_map[i].label;
		}
	}

	return runstate_map[0].label;
}

enum ctdb_runstate runstate_from_string(const char *label)
{
	int i;
	for (i=0; runstate_map[i].label != NULL; i++) {
		if (strcasecmp(runstate_map[i].label, label) == 0) {
			return runstate_map[i].runstate;
		}
	}

	return CTDB_RUNSTATE_UNKNOWN;
}

void ctdb_set_runstate(struct ctdb_context *ctdb, enum ctdb_runstate runstate)
{
	if (runstate <= ctdb->runstate) {
		ctdb_fatal(ctdb, "runstate must always increase");
	}

	DEBUG(DEBUG_NOTICE,("Set runstate to %s (%d)\n",
			    runstate_to_string(runstate), runstate));
	ctdb->runstate = runstate;
}

void ctdb_mkdir_p_or_die(struct ctdb_context *ctdb, const char *dir, int mode)
{
	int ret;

	ret = mkdir_p(dir, mode);
	if (ret != 0) {
		DEBUG(DEBUG_ALERT,
		      ("ctdb exiting with error: "
		       "failed to create directory \"%s\" (%s)\n",
		       dir, strerror(errno)));
		exit(1);
	}
}