/* 
   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 "replace.h"
#include "system/network.h"
#include "system/filesys.h"
#include "system/wait.h"

#include <tdb.h>

#include "lib/util/debug.h"
#include "lib/util/samba_util.h"

#include "ctdb_private.h"

#include "common/reqid.h"
#include "common/system.h"
#include "common/common.h"
#include "common/logging.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);
}

/* Set the path of a helper program from envvar, falling back to
 * dir/file if envvar unset. type is a string to print in log
 * messages.  helper is assumed to point to a statically allocated
 * array of size bytes, initialised to "".  If file is NULL don't fall
 * back if envvar is unset.  If dir is NULL and envvar is unset (but
 * file is not NULL) then this is an error.  Returns true if helper is
 * set, either previously or this time. */
bool ctdb_set_helper(const char *type, char *helper, size_t size,
		     const char *envvar,
		     const char *dir, const char *file)
{
	const char *t;
	struct stat st;

	if (helper[0] != '\0') {
		/* Already set */
		return true;
	}

	t = getenv(envvar);
	if (t != NULL) {
		if (strlen(t) >= size) {
			DEBUG(DEBUG_ERR,
			      ("Unable to set %s - path too long\n", type));
			return false;
		}

		strncpy(helper, t, size);
	} else if (file == NULL) {
		return false;
	} else if (dir == NULL) {
			DEBUG(DEBUG_ERR,
			      ("Unable to set %s - dir is NULL\n", type));
		return false;
	} else {
		if (snprintf(helper, size, "%s/%s", dir, file) >= size) {
			DEBUG(DEBUG_ERR,
			      ("Unable to set %s - path too long\n", type));
			return false;
		}
	}

	if (stat(helper, &st) != 0) {
		DEBUG(DEBUG_ERR,
		      ("Unable to set %s \"%s\" - %s\n",
		       type, helper, strerror(errno)));
		return false;
	}
	if (!(st.st_mode & S_IXUSR)) {
		DEBUG(DEBUG_ERR,
		      ("Unable to set %s \"%s\" - not executable\n",
		       type, helper));
		return false;
	}

	DEBUG(DEBUG_NOTICE,
	      ("Set %s to \"%s\"\n", type, helper));
	return true;
}

/* 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)
{
	int ret;
	static char external_trace[PATH_MAX+1] = "";
	char * cmd;

	if (!ctdb_set_helper("external trace handler",
			     external_trace, sizeof(external_trace),
			     "CTDB_EXTERNAL_TRACE", NULL, NULL)) {
		return;
	}

	cmd = talloc_asprintf(NULL, "%s %lu", external_trace, (unsigned long) getpid());
	DEBUG(DEBUG_WARNING,("begin external trace: %s\n", cmd));
	ret = system(cmd);
	if (ret == -1) {
		DEBUG(DEBUG_ERR,
		      ("external trace command \"%s\" failed\n", cmd));
	}
	DEBUG(DEBUG_WARNING,("end external trace: %s\n", cmd));
	talloc_free(cmd);
}

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

	setservent(0);
	se = getservbyname("ctdb", "tcp");
	endservent();

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

	if (! parse_ip(str, NULL, port, address)) {
		return -1;
	}

	return 0;
}


/*
  check if two addresses are the same
*/
bool ctdb_same_address(ctdb_sock_addr *a1, ctdb_sock_addr *a2)
{
	return ctdb_same_ip(a1, a2) &&
		ctdb_addr_to_port(a1) == ctdb_addr_to_port(a2);
}


/*
  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));
}


static uint32_t ctdb_marshall_record_size(TDB_DATA key,
					  struct ctdb_ltdb_header *header,
					  TDB_DATA data)
{
	return offsetof(struct ctdb_rec_data_old, data) + key.dsize +
	       data.dsize + (header ? sizeof(*header) : 0);
}

static void ctdb_marshall_record_copy(struct ctdb_rec_data_old *rec,
				      uint32_t reqid,
				      TDB_DATA key,
				      struct ctdb_ltdb_header *header,
				      TDB_DATA data,
				      uint32_t length)
{
	uint32_t offset;

	rec->length = length;
	rec->reqid = reqid;
	rec->keylen = key.dsize;
	memcpy(&rec->data[0], key.dptr, key.dsize);
	offset = key.dsize;

	if (header) {
		rec->datalen = data.dsize + sizeof(*header);
		memcpy(&rec->data[offset], header, sizeof(*header));
		offset += sizeof(*header);
	} else {
		rec->datalen = data.dsize;
	}
	memcpy(&rec->data[offset], data.dptr, data.dsize);
}

/*
  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_old *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_old *d;

	length = ctdb_marshall_record_size(key, header, data);

	d = (struct ctdb_rec_data_old *)talloc_size(mem_ctx, length);
	if (d == NULL) {
		return NULL;
	}

	ctdb_marshall_record_copy(d, reqid, key, header, data, length);
	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_old *r;
	struct ctdb_marshall_buffer *m2;
	uint32_t length, offset;

	length = ctdb_marshall_record_size(key, header, data);

	if (m == NULL) {
		offset = offsetof(struct ctdb_marshall_buffer, data);
		m2 = talloc_zero_size(mem_ctx, offset + length);
	} else {
		offset = talloc_get_size(m);
		m2 = talloc_realloc_size(mem_ctx, m, offset + length);
	}
	if (m2 == NULL) {
		TALLOC_FREE(m);
		return NULL;
	}

	if (m == NULL) {
		m2->db_id = db_id;
	}

	r = (struct ctdb_rec_data_old *)((uint8_t *)m2 + offset);
	ctdb_marshall_record_copy(r, reqid, key, header, data, length);
	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_old *ctdb_marshall_loop_next(
				struct ctdb_marshall_buffer *m,
				struct ctdb_rec_data_old *r,
				uint32_t *reqid,
				struct ctdb_ltdb_header *header,
				TDB_DATA *key, TDB_DATA *data)
{
	if (r == NULL) {
		r = (struct ctdb_rec_data_old *)&m->data[0];
	} else {
		r = (struct ctdb_rec_data_old *)(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;
		}
		memcpy(header, &r->data[r->keylen], sizeof(*header));
	}

	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;
}

/* Add a node to a node map with given address and flags */
static bool node_map_add(TALLOC_CTX *mem_ctx,
			 const char *nstr, uint32_t flags,
			 struct ctdb_node_map_old **node_map)
{
	ctdb_sock_addr addr;
	uint32_t num;
	size_t s;
	struct ctdb_node_and_flags *n;

	/* Might as well do this before trying to allocate memory */
	if (ctdb_parse_address(mem_ctx, nstr, &addr) == -1) {
		return false;
	}

	num = (*node_map)->num + 1;
	s = offsetof(struct ctdb_node_map_old, nodes) +
		num * sizeof(struct ctdb_node_and_flags);
	*node_map = talloc_realloc_size(mem_ctx, *node_map, s);
	if (*node_map == NULL) {
		DEBUG(DEBUG_ERR, (__location__ " Out of memory\n"));
		return false;
	}

	n = &(*node_map)->nodes[(*node_map)->num];
	n->addr = addr;
	n->pnn = (*node_map)->num;
	n->flags = flags;

	(*node_map)->num++;

	return true;
}

/* Read a nodes file into a node map */
struct ctdb_node_map_old *ctdb_read_nodes_file(TALLOC_CTX *mem_ctx,
					   const char *nlist)
{
	char **lines;
	int nlines;
	int i;
	struct ctdb_node_map_old *ret;

	/* Allocate node map header */
	ret = talloc_zero_size(mem_ctx, offsetof(struct ctdb_node_map_old, nodes));
	if (ret == NULL) {
		DEBUG(DEBUG_ERR, (__location__ " Out of memory\n"));
		return false;
	}

	lines = file_lines_load(nlist, &nlines, 0, mem_ctx);
	if (lines == NULL) {
		DEBUG(DEBUG_ERR, ("Failed to read nodes file \"%s\"\n", nlist));
		return false;
	}
	while (nlines > 0 && strcmp(lines[nlines-1], "") == 0) {
		nlines--;
	}

	for (i=0; i < nlines; i++) {
		char *node;
		uint32_t flags;
		size_t len;

		node = lines[i];
		/* strip leading spaces */
		while((*node == ' ') || (*node == '\t')) {
			node++;
		}

		len = strlen(node);

		while ((len > 1) &&
		       ((node[len-1] == ' ') || (node[len-1] == '\t')))
		{
			node[len-1] = '\0';
			len--;
		}

		if (len == 0) {
			continue;
		}
		if (*node == '#') {
			/* A "deleted" node is a node that is
			   commented out in the nodes file.  This is
			   used instead of removing a line, which
			   would cause subsequent nodes to change
			   their PNN. */
			flags = NODE_FLAGS_DELETED;
			node = discard_const("0.0.0.0");
		} else {
			flags = 0;
		}
		if (!node_map_add(mem_ctx, node, flags, &ret)) {
			talloc_free(lines);
			TALLOC_FREE(ret);
			return NULL;
		}
	}

	talloc_free(lines);
	return ret;
}

struct ctdb_node_map_old *
ctdb_node_list_to_map(struct ctdb_node **nodes, uint32_t num_nodes,
		      TALLOC_CTX *mem_ctx)
{
	uint32_t i;
	size_t size;
	struct ctdb_node_map_old *node_map;

	size = offsetof(struct ctdb_node_map_old, nodes) +
		num_nodes * sizeof(struct ctdb_node_and_flags);
	node_map  = (struct ctdb_node_map_old *)talloc_zero_size(mem_ctx, size);
	if (node_map == NULL) {
		DEBUG(DEBUG_ERR,
		      (__location__ " Failed to allocate nodemap array\n"));
		return NULL;
	}

	node_map->num = num_nodes;
	for (i=0; i<num_nodes; i++) {
		node_map->nodes[i].addr  = nodes[i]->address;
		node_map->nodes[i].pnn   = nodes[i]->pnn;
		node_map->nodes[i].flags = nodes[i]->flags;
	}

	return node_map;
}

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)
{
	DEBUG(DEBUG_NOTICE,("Set runstate to %s (%d)\n",
			    runstate_to_string(runstate), runstate));

	if (runstate <= ctdb->runstate) {
		ctdb_fatal(ctdb, "runstate must always increase");
	}

	ctdb->runstate = runstate;
}

/* Convert arbitrary data to 4-byte boundary padded uint32 array */
uint32_t *ctdb_key_to_idkey(TALLOC_CTX *mem_ctx, TDB_DATA key)
{
	uint32_t idkey_size, *k;

	idkey_size = 1 + (key.dsize + sizeof(uint32_t)-1) / sizeof(uint32_t);

	k = talloc_zero_array(mem_ctx, uint32_t, idkey_size);
	if (k == NULL) {
		return NULL;
	}

	k[0] = idkey_size;
	memcpy(&k[1], key.dptr, key.dsize);

	return k;
}