s4-dsdb: Add documentation link for Tombstone Reanimation

[Samba.git] / 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 "../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)
{
        int ret;
        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));
        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(struct ctdb_context *ctdb,
                       TALLOC_CTX *mem_ctx, const char *str,
                       struct ctdb_address *address)
{
        struct servent *se;
        ctdb_sock_addr addr;

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

        /* Parse IP address and re-convert to string.  This ensure correct
         * string form for IPv6 addresses.
         */
        if (! parse_ip(str, NULL, 0, &addr)) {
                return -1;
        }

        address->address = talloc_strdup(mem_ctx, ctdb_addr_to_str(&addr));
        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"));
        }
}


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

static void ctdb_marshall_record_copy(struct ctdb_rec_data *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 *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 = ctdb_marshall_record_size(key, header, data);

        d = (struct ctdb_rec_data *)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 *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 *)((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 *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;
                }
                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;
}


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;
}

/* 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;
}