source: vendor/current/ctdb/common/system_util.c

/*
   common system utilities

   Copyright (C) Amitay Isaacs  2014
   Copyright (C) Martin Schwenke  2014

   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/filesys.h"
#include "system/shmem.h"
#include "system/network.h"

#include <libgen.h>

#include "lib/util/debug.h"

#include "protocol/protocol.h"

#include "common/logging.h"
#include "common/system.h"

#if HAVE_SCHED_H
#include <sched.h>
#endif

#if HAVE_PROCINFO_H
#include <procinfo.h>
#endif

/*
  if possible, make this task real time
 */
bool set_scheduler(void)
{
#ifdef _AIX_
#if HAVE_THREAD_SETSCHED
        struct thrdentry64 te;
        tid64_t ti;

        ti = 0ULL;
        if (getthrds64(getpid(), &te, sizeof(te), &ti, 1) != 1) {
                DEBUG(DEBUG_ERR, ("Unable to get thread information\n"));
                return false;
        }

        if (thread_setsched(te.ti_tid, 0, SCHED_RR) == -1) {
                DEBUG(DEBUG_ERR, ("Unable to set scheduler to SCHED_RR (%s)\n",
                                  strerror(errno)));
                return false;
        } else {
                return true;
        }
#endif
#else /* no AIX */
#if HAVE_SCHED_SETSCHEDULER
        struct sched_param p;
        int policy = SCHED_FIFO;

        p.sched_priority = 1;

#ifdef SCHED_RESET_ON_FORK
        policy |= SCHED_RESET_ON_FORK;
#endif
        if (sched_setscheduler(0, policy, &p) == -1) {
                DEBUG(DEBUG_CRIT,("Unable to set scheduler to SCHED_FIFO (%s)\n",
                         strerror(errno)));
                return false;
        } else {
                return true;
        }
#endif
#endif
        DEBUG(DEBUG_CRIT,("No way to set real-time priority.\n"));
        return false;
}

/*
  reset scheduler from real-time to normal scheduling
 */
void reset_scheduler(void)
{
#ifdef _AIX_
#if HAVE_THREAD_SETSCHED
        struct thrdentry64 te;
        tid64_t ti;

        ti = 0ULL;
        if (getthrds64(getpid(), &te, sizeof(te), &ti, 1) != 1) {
                DEBUG(DEBUG_ERR, ("Unable to get thread information\n"));
        }
        if (thread_setsched(te.ti_tid, 0, SCHED_OTHER) == -1) {
                DEBUG(DEBUG_ERR, ("Unable to set scheduler to SCHED_OTHER\n"));
        }
#endif
#else /* no AIX */
#if HAVE_SCHED_SETSCHEDULER
#ifndef SCHED_RESET_ON_FORK
        struct sched_param p;

        p.sched_priority = 0;
        if (sched_setscheduler(0, SCHED_OTHER, &p) == -1) {
                DEBUG(DEBUG_ERR, ("Unable to set scheduler to SCHED_OTHER\n"));
        }
#endif
#endif
#endif
}

void set_nonblocking(int fd)
{
        int v;

        v = fcntl(fd, F_GETFL, 0);
        if (v == -1) {
                DEBUG(DEBUG_WARNING, ("Failed to get file status flags - %s\n",
                                      strerror(errno)));
                return;
        }
        if (fcntl(fd, F_SETFL, v | O_NONBLOCK) == -1) {
                DEBUG(DEBUG_WARNING, ("Failed to set non_blocking on fd - %s\n",
                                      strerror(errno)));
        }
}

void set_close_on_exec(int fd)
{
        int v;

        v = fcntl(fd, F_GETFD, 0);
        if (v == -1) {
                DEBUG(DEBUG_WARNING, ("Failed to get file descriptor flags - %s\n",
                                      strerror(errno)));
                return;
        }
        if (fcntl(fd, F_SETFD, v | FD_CLOEXEC) != 0) {
                DEBUG(DEBUG_WARNING, ("Failed to set close_on_exec on fd - %s\n",
                                      strerror(errno)));
        }
}


bool parse_ipv4(const char *s, unsigned port, struct sockaddr_in *sin)
{
        sin->sin_family = AF_INET;
        sin->sin_port   = htons(port);

        if (inet_pton(AF_INET, s, &sin->sin_addr) != 1) {
                DEBUG(DEBUG_ERR, (__location__ " Failed to translate %s into sin_addr\n", s));
                return false;
        }

#ifdef HAVE_SOCK_SIN_LEN
        sin->sin_len = sizeof(*sin);
#endif
        return true;
}

static bool parse_ipv6(const char *s, const char *ifaces, unsigned port, ctdb_sock_addr *saddr)
{
        saddr->ip6.sin6_family   = AF_INET6;
        saddr->ip6.sin6_port     = htons(port);
        saddr->ip6.sin6_flowinfo = 0;
        saddr->ip6.sin6_scope_id = 0;

        if (inet_pton(AF_INET6, s, &saddr->ip6.sin6_addr) != 1) {
                DEBUG(DEBUG_ERR, (__location__ " Failed to translate %s into sin6_addr\n", s));
                return false;
        }

        if (ifaces && IN6_IS_ADDR_LINKLOCAL(&saddr->ip6.sin6_addr)) {
                if (strchr(ifaces, ',')) {
                        DEBUG(DEBUG_ERR, (__location__ " Link local address %s "
                                          "is specified for multiple ifaces %s\n",
                                          s, ifaces));
                        return false;
                }
                saddr->ip6.sin6_scope_id = if_nametoindex(ifaces);
        }

#ifdef HAVE_SOCK_SIN_LEN
        saddr->ip6.sin6_len = sizeof(*saddr);
#endif
        return true;
}

/*
  parse an ip
 */
bool parse_ip(const char *addr, const char *ifaces, unsigned port, ctdb_sock_addr *saddr)
{
        char *p;
        bool ret;

        ZERO_STRUCTP(saddr); /* valgrind :-) */

        /* now is this a ipv4 or ipv6 address ?*/
        p = index(addr, ':');
        if (p == NULL) {
                ret = parse_ipv4(addr, port, &saddr->ip);
        } else {
                ret = parse_ipv6(addr, ifaces, port, saddr);
        }

        return ret;
}

/*
  parse a ip/mask pair
 */
bool parse_ip_mask(const char *str, const char *ifaces, ctdb_sock_addr *addr, unsigned *mask)
{
        char *p;
        char s[64]; /* Much longer than INET6_ADDRSTRLEN */
        char *endp = NULL;
        ssize_t len;
        bool ret;

        ZERO_STRUCT(*addr);

        len = strlen(str);
        if (len >= sizeof(s)) {
                DEBUG(DEBUG_ERR, ("Address %s is unreasonably long\n", str));
                return false;
        }

        strncpy(s, str, len+1);

        p = rindex(s, '/');
        if (p == NULL) {
                DEBUG(DEBUG_ERR, (__location__ " This addr: %s does not contain a mask\n", s));
                return false;
        }

        *mask = strtoul(p+1, &endp, 10);
        if (endp == NULL || *endp != 0) {
                /* trailing garbage */
                DEBUG(DEBUG_ERR, (__location__ " Trailing garbage after the mask in %s\n", s));
                return false;
        }
        *p = 0;


        /* now is this a ipv4 or ipv6 address ?*/
        ret = parse_ip(s, ifaces, 0, addr);

        return ret;
}

/*
  parse a ip:port pair
 */
bool parse_ip_port(const char *addr, ctdb_sock_addr *saddr)
{
        char *p;
        char s[64]; /* Much longer than INET6_ADDRSTRLEN */
        unsigned port;
        char *endp = NULL;
        ssize_t len;
        bool ret;

        len = strlen(addr);
        if (len >= sizeof(s)) {
                DEBUG(DEBUG_ERR, ("Address %s is unreasonably long\n", addr));
                return false;
        }

        strncpy(s, addr, len+1);

        p = rindex(s, ':');
        if (p == NULL) {
                DEBUG(DEBUG_ERR, (__location__ " This addr: %s does not contain a port number\n", s));
                return false;
        }

        port = strtoul(p+1, &endp, 10);
        if (endp == NULL || *endp != 0) {
                /* trailing garbage */
                DEBUG(DEBUG_ERR, (__location__ " Trailing garbage after the port in %s\n", s));
                return false;
        }
        *p = 0;

        /* now is this a ipv4 or ipv6 address ?*/
        ret = parse_ip(s, NULL, port, saddr);

        return ret;
}

/* 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
}

int mkdir_p(const char *dir, int mode)
{
        char t[PATH_MAX];
        ssize_t len;
        int ret;

        if (strcmp(dir, "/") == 0) {
                return 0;
        }

        if (strcmp(dir, ".") == 0) {
                return 0;
        }

        /* Try to create directory */
        ret = mkdir(dir, mode);
        /* Succeed if that worked or if it already existed */
        if (ret == 0 || errno == EEXIST) {
                return 0;
        }
        /* Fail on anything else except ENOENT */
        if (errno != ENOENT) {
                return ret;
        }

        /* Create ancestors */
        len = strlen(dir);
        if (len >= PATH_MAX) {
                errno = ENAMETOOLONG;
                return -1;
        }
        strncpy(t, dir, len+1);

        ret = mkdir_p(dirname(t), mode);
        if (ret != 0) {
                return ret;
        }

        /* Create directory */
        ret = mkdir(dir, mode);
        if ((ret == -1) && (errno == EEXIST)) {
                ret = 0;
        }

        return ret;
}

void mkdir_p_or_die(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);
        }
}

/* A read wrapper that will deal with EINTR.  For now, copied from
 * source3/lib/system.c
 */
ssize_t sys_read(int fd, void *buf, size_t count)
{
        ssize_t ret;

        do {
                ret = read(fd, buf, count);
#if defined(EWOULDBLOCK)
        } while (ret == -1 && (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK));
#else
        } while (ret == -1 && (errno == EINTR || errno == EAGAIN));
#endif
        return ret;
}

/* A write wrapper that will deal with EINTR.  For now, copied from
 * source3/lib/system.c
 */
ssize_t sys_write(int fd, const void *buf, size_t count)
{
        ssize_t ret;

        do {
                ret = write(fd, buf, count);
#if defined(EWOULDBLOCK)
        } while (ret == -1 && (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK));
#else
        } while (ret == -1 && (errno == EINTR || errno == EAGAIN));
#endif
        return ret;
}