/*

 * ProFTPD - FTP server daemon

 * Copyright (c) 2007-2018 The ProFTPD Project team

 *

 * 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 2 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, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA.

 *

 * As a special exemption, The ProFTPD Project team and other respective

 * copyright holders give permission to link this program with OpenSSL, and

 * distribute the resulting executable, without including the source code for

 * OpenSSL in the source distribution.

 */

/* Proctitle management */

#include "conf.h"

#if PF_ARGV_TYPE == PF_ARGV_PSTAT

# ifdef HAVE_SYS_PSTAT_H

#  include <sys/pstat.h>

# else

#  undef PF_ARGV_TYPE

#  define PF_ARGV_TYPE PF_ARGV_WRITEABLE

# endif /* HAVE_SYS_PSTAT_H */

#endif /* PF_ARGV_PSTAT */

#if PF_ARGV_TYPE == PF_ARGV_PSSTRINGS

# ifndef HAVE_SYS_EXEC_H

#  undef PF_ARGV_TYPE

#  define PF_ARGV_TYPE PF_ARGV_WRITEABLE

# else

#  include <machine/vmparam.h>

#  include <sys/exec.h>

# endif /* HAVE_SYS_EXEC_H */

#endif /* PF_ARGV_PSSTRINGS */

#ifdef HAVE___PROGNAME

extern char *__progname, *__progname_full;

#endif /* HAVE___PROGNAME */

extern char **environ;

static char **prog_argv = NULL;

static char *prog_last_argv = NULL;

static int prog_argc = -1;

static char proc_title_buf[BUFSIZ];

static unsigned int proc_flags = 0;

#define PR_PROCTITLE_FL_USE_STATIC    0x001

void pr_proctitle_init(int argc, char *argv[], char *envp[]) {

  register int i, j;

  register size_t envpsize;

  char **p;

  /* Move the environment so setproctitle can use the space. */

  for (i = envpsize = 0; envp[i] != NULL; i++) {

    envpsize += strlen(envp[i]) + 1;

  }

  p = (char **) calloc((i + 1), sizeof(char *));

  if (p != NULL) {

    environ = p;

    j = 0;

    for (i = 0; envp[i] != NULL; i++) {

      size_t envp_len = strlen(envp[i]);

      if (envp_len > PR_TUNABLE_ENV_MAX) {

        /* Skip any environ variables that are too long. */

        continue;

      }

      environ[j] = malloc(envp_len + 1);

      if (environ[j] != NULL) {

        sstrncpy(environ[j], envp[i], envp_len + 1);

        j++;

      }

    }

  }

  prog_argv = argv;

  prog_argc = argc;

  for (i = 0; i < prog_argc; i++) {

    if (!i || (prog_last_argv + 1 == argv[i])) {

      prog_last_argv = argv[i] + strlen(argv[i]);

    }

  }

  for (i = 0; envp[i] != NULL; i++) {

    if ((prog_last_argv + 1) == envp[i]) {

      prog_last_argv = envp[i] + strlen(envp[i]);

    }

  }

#ifdef HAVE___PROGNAME

  /* Set the __progname and __progname_full variables so glibc and company

   * don't go nuts.

   */

  __progname = strdup("proftpd");

  __progname_full = strdup(argv[0]);

#endif /* HAVE___PROGNAME */

  memset(proc_title_buf, '\0', sizeof(proc_title_buf));

}

void pr_proctitle_free(void) {

#ifdef PR_USE_DEVEL

  if (environ) {

    register unsigned int i;

    for (i = 0; environ[i] != NULL; i++) {

      free(environ[i]);

    }

    free(environ);

    environ = NULL;

  }

# ifdef HAVE___PROGNAME

  free(__progname);

  __progname = NULL;

  free(__progname_full);

  __progname_full = NULL;

# endif /* HAVE___PROGNAME */

#endif /* PR_USE_DEVEL */

}

void pr_proctitle_set_str(const char *str) {

#ifndef HAVE_SETPROCTITLE

  char *p;

  int i, procbuflen, maxlen = (prog_last_argv - prog_argv[0]) - 2;

# if PF_ARGV_TYPE == PF_ARGV_PSTAT

  union pstun pst;

# endif /* PF_ARGV_PSTAT */

  if (proc_flags & PR_PROCTITLE_FL_USE_STATIC) {

    return;

  }

  sstrncpy(proc_title_buf, str, sizeof(proc_title_buf));

  procbuflen = strlen(proc_title_buf);

# if PF_ARGV_TYPE == PF_ARGV_NEW

  /* We can just replace argv[] arguments.  Nice and easy. */

  prog_argv[0] = proc_title_buf;

  for (i = 1; i < prog_argc; i++) {

    prog_argv[i] = "";

  }

# endif /* PF_ARGV_NEW */

# if PF_ARGV_TYPE == PF_ARGV_WRITEABLE

  /* We can overwrite individual argv[] arguments.  Semi-nice. */

  snprintf(prog_argv[0], maxlen, "%s", proc_title_buf);

  p = &prog_argv[0][procbuflen];

  while (p < prog_last_argv) {

    *p++ = '\0';

  }

  for (i = 1; i < prog_argc; i++) {

    prog_argv[i] = "";

  }

# endif /* PF_ARGV_WRITEABLE */

# if PF_ARGV_TYPE == PF_ARGV_PSSTRINGS

  PS_STRINGS->ps_nargvstr = 1;

  PS_STRINGS->ps_argvstr = proc_title_buf;

# endif /* PF_ARGV_PSSTRINGS */

#else

  if (proc_flags & PR_PROCTITLE_FL_USE_STATIC) {

    return;

  }

  setproctitle("%s", str);

#endif /* HAVE_SETPROCTITLE */

}

/* Note that we deliberately do NOT use pr_vsnprintf() here, since truncation

 * of long strings is often normal for these entries; consider paths longer

 * than PR_TUNABLE_SCOREBOARD_BUFFER_SIZE (Issue#683).

 */

void pr_proctitle_set(const char *fmt, ...) {

  va_list msg;

#ifndef HAVE_SETPROCTITLE

# if PF_ARGV_TYPE == PF_ARGV_PSTAT

  union pstun pst;

# endif /* PF_ARGV_PSTAT */

  char *p;

  int i, procbuflen, maxlen = (prog_last_argv - prog_argv[0]) - 2;

#endif /* HAVE_SETPROCTITLE */

  if (proc_flags & PR_PROCTITLE_FL_USE_STATIC) {

    return;

  }

  if (fmt == NULL) {

    return;

  }

  va_start(msg, fmt);

  memset(proc_title_buf, 0, sizeof(proc_title_buf));

#ifdef HAVE_SETPROCTITLE

# if __FreeBSD__ >= 4 && !defined(FREEBSD4_0) && !defined(FREEBSD4_1)

  /* FreeBSD's setproctitle() automatically prepends the process name. */

  vsnprintf(proc_title_buf, sizeof(proc_title_buf)-1, fmt, msg);

# else /* FREEBSD4 */

  /* Manually append the process name for non-FreeBSD platforms. */

  snprintf(proc_title_buf, sizeof(proc_title_buf)-1, "%s", "proftpd: ");

  vsnprintf(proc_title_buf + strlen(proc_title_buf),

    sizeof(proc_title_buf)-1 - strlen(proc_title_buf), fmt, msg);

# endif /* FREEBSD4 */

  setproctitle("%s", proc_title_buf);

#else /* HAVE_SETPROCTITLE */

  /* Manually append the process name for non-setproctitle() platforms. */

  snprintf(proc_title_buf, sizeof(proc_title_buf)-1, "%s", "proftpd: ");

  vsnprintf(proc_title_buf + strlen(proc_title_buf),

    sizeof(proc_title_buf)-1 - strlen(proc_title_buf), fmt, msg);

#endif /* HAVE_SETPROCTITLE */

  va_end(msg);

#ifdef HAVE_SETPROCTITLE

  return;

#else

  procbuflen = strlen(proc_title_buf);

# if PF_ARGV_TYPE == PF_ARGV_NEW

  /* We can just replace argv[] arguments.  Nice and easy. */

  prog_argv[0] = proc_title_buf;

  for (i = 1; i < prog_argc; i++) {

    prog_argv[i] = "";

  }

# endif /* PF_ARGV_NEW */

# if PF_ARGV_TYPE == PF_ARGV_WRITEABLE

  /* We can overwrite individual argv[] arguments.  Semi-nice. */

  snprintf(prog_argv[0], maxlen, "%s", proc_title_buf);

  p = &prog_argv[0][procbuflen];

  while (p < prog_last_argv) {

    *p++ = '\0';

  }

  for (i = 1; i < prog_argc; i++) {

    prog_argv[i] = "";

  }

# endif /* PF_ARGV_WRITEABLE */

# if PF_ARGV_TYPE == PF_ARGV_PSTAT

  pst.pst_command = proc_title_buf;

  pstat(PSTAT_SETCMD, pst, procbuflen, 0, 0);

# endif /* PF_ARGV_PSTAT */

# if PF_ARGV_TYPE == PF_ARGV_PSSTRINGS

  PS_STRINGS->ps_nargvstr = 1;

  PS_STRINGS->ps_argvstr = proc_title_buf;

# endif /* PF_ARGV_PSSTRINGS */

#endif /* HAVE_SETPROCTITLE */

}

void pr_proctitle_set_static_str(const char *buf) {

  if (buf != NULL) {

    pr_proctitle_set_str(buf);

    proc_flags |= PR_PROCTITLE_FL_USE_STATIC;

  } else {

    /* Reset. */

    proc_flags = 0;

  }

}

int pr_proctitle_get(char *buf, size_t bufsz) {

  if (buf == NULL ||

      bufsz == 0) {

    /* If the caller didn't provide an input buffer, they are simply

     * querying for the length of the current process title.  Easy enough

     * to acquiesce to that request.

     */

    return strlen(proc_title_buf);

  }

  sstrncpy(buf, proc_title_buf, bufsz);

  return strlen(buf);

}