/*
 * Dropbear - a SSH2 server
 * 
 * Copyright (c) 2002,2003 Matt Johnston
 * All rights reserved.
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * strlcat() is copyright as follows:
 * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */

#include "includes.h"
#include "dbutil.h"
#include "buffer.h"
#include "session.h"
#include "atomicio.h"

#define MAX_FMT 100

static void generic_dropbear_exit(int exitcode, const char* format, 
    va_list param);
static void generic_dropbear_log(int priority, const char* format, 
    va_list param);

void (*_dropbear_exit)(int exitcode, const char* format, va_list param) 
            = generic_dropbear_exit;
void (*_dropbear_log)(int priority, const char* format, va_list param)
            = generic_dropbear_log;

#ifdef DEBUG_TRACE
int debug_trace = 1;
#endif

#ifndef DISABLE_SYSLOG
void startsyslog() {

# if 0 //LUDO:
  openlog(PROGNAME, LOG_PID, LOG_AUTHPRIV);
# endif

}
#endif /* DISABLE_SYSLOG */

/* the "format" string must be <= 100 characters */
void dropbear_close(const char* format, ...) {

  va_list param;

  va_start(param, format);
  _dropbear_exit(EXIT_SUCCESS, format, param);
  va_end(param);

}

void dropbear_exit(const char* format, ...) {

  va_list param;

  va_start(param, format);
  _dropbear_exit(EXIT_FAILURE, format, param);
  va_end(param);
}

static void generic_dropbear_exit(int exitcode, const char* format, 
    va_list param) {

  char fmtbuf[300];

  snprintf(fmtbuf, sizeof(fmtbuf), "Exited: %s", format);
  _dropbear_log(LOG_INFO, fmtbuf, param);
  exit(exitcode);
}

void fail_assert(const char* expr, const char* file, int line) {
  dropbear_exit("failed assertion (%s:%d): `%s'", file, line, expr);
}

static void generic_dropbear_log(int UNUSED(priority), const char* format, 
    va_list param) {

  char printbuf[1024];

  vsnprintf(printbuf, sizeof(printbuf), format, param);

  fprintf(stderr, "%s\n", printbuf);

}

/* this is what can be called to write arbitrary log messages */
void dropbear_log(int priority, const char* format, ...) {

  va_list param;

  va_start(param, format);
  _dropbear_log(priority, format, param);
  va_end(param);
}


#ifdef DEBUG_TRACE
void dropbear_trace(const char* format, ...) {

  va_list param;

  if (!debug_trace) {
    return;
  }

  va_start(param, format);
  fprintf(stderr, "TRACE: ");
  vfprintf(stderr, format, param);
  fprintf(stderr, "\n");
  va_end(param);
}
#endif /* DEBUG_TRACE */

static void set_sock_priority(int sock) {

  int val;

  /* disable nagle */
  val = 1;
  setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, (void*)&val, sizeof(val));

  /* set the TOS bit. note that this will fail for ipv6, I can't find any
   * equivalent. */
#ifdef IPTOS_LOWDELAY
  val = IPTOS_LOWDELAY;
  setsockopt(sock, IPPROTO_IP, IP_TOS, (void*)&val, sizeof(val));
#endif

#ifdef SO_PRIORITY
  /* linux specific, sets QoS class.
   * 6 looks to be optimal for interactive traffic (see tc-prio(8) ). */
  val = 6;
  setsockopt(sock, SOL_SOCKET, SO_PRIORITY, (void*) &val, sizeof(val));
#endif

}

/* Listen on address:port. 
 * Special cases are address of "" listening on everything,
 * and address of NULL listening on localhost only.
 * Returns the number of sockets bound on success, or -1 on failure. On
 * failure, if errstring wasn't NULL, it'll be a newly malloced error
 * string.*/
int dropbear_listen(const char* address, const char* port,
    int *socks, unsigned int sockcount, char **errstring, int *maxfd) {

  struct addrinfo hints, *res = NULL, *res0 = NULL;
  int err;
  unsigned int nsock;
  struct linger linger;
  int val;
  int sock;

  TRACE(("enter dropbear_listen"))
  
  memset(&hints, 0, sizeof(hints));
  hints.ai_family = AF_UNSPEC; /* TODO: let them flag v4 only etc */
  hints.ai_socktype = SOCK_STREAM;

  // for calling getaddrinfo:
  // address == NULL and !AI_PASSIVE: local loopback
  // address == NULL and AI_PASSIVE: all interfaces
  // address != NULL: whatever the address says
  if (!address) {
    TRACE(("dropbear_listen: local loopback"))
  } else {
    if (address[0] == '\0') {
      TRACE(("dropbear_listen: all interfaces"))
      address = NULL;
    }
    hints.ai_flags = AI_PASSIVE;
  }
  err = getaddrinfo(address, port, &hints, &res0);

  if (err) {
    if (errstring != NULL && *errstring == NULL) {
      int len;
      len = 20 + strlen(gai_strerror(err));
      *errstring = (char*)m_malloc(len);
      snprintf(*errstring, len, "Error resolving: %s", gai_strerror(err));
    }
    if (res0) {
      freeaddrinfo(res0);
      res0 = NULL;
    }
    TRACE(("leave dropbear_listen: failed resolving"))
    return -1;
  }


  nsock = 0;
  for (res = res0; res != NULL && nsock < sockcount;
      res = res->ai_next) {

    /* Get a socket */
    socks[nsock] = socket(res->ai_family, res->ai_socktype,
        res->ai_protocol);

    sock = socks[nsock]; /* For clarity */

    if (sock < 0) {
      err = errno;
      TRACE(("socket() failed"))
      continue;
    }

    /* Various useful socket options */
    val = 1;
    /* set to reuse, quick timeout */
    setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void*) &val, sizeof(val));
    linger.l_onoff = 1;
    linger.l_linger = 5;
    setsockopt(sock, SOL_SOCKET, SO_LINGER, (void*)&linger, sizeof(linger));

    set_sock_priority(sock);

    if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) {
      err = errno;
      close(sock);
      TRACE(("bind(%s) failed", port))
      continue;
    }

    if (listen(sock, 20) < 0) {
      err = errno;
      close(sock);
      TRACE(("listen() failed"))
      continue;
    }

    *maxfd = MAX(*maxfd, sock);

    nsock++;
  }

  if (res0) {
    freeaddrinfo(res0);
    res0 = NULL;
  }

  if (nsock == 0) {
    if (errstring != NULL && *errstring == NULL) {
      int len;
      len = 20 + strlen(strerror(err));
      *errstring = (char*)m_malloc(len);
      snprintf(*errstring, len, "Error listening: %s", strerror(err));
      TRACE(("leave dropbear_listen: failure, %s", strerror(err)))
      return -1;
    }
  }

  TRACE(("leave dropbear_listen: success, %d socks bound", nsock))
  return nsock;
}

/* Connect via TCP to a host. Connection will try ipv4 or ipv6, will
 * return immediately if nonblocking is set. On failure, if errstring
 * wasn't null, it will be a newly malloced error message */

/* TODO: maxfd */
int connect_remote(const char* remotehost, const char* remoteport,
    int nonblocking, char ** errstring) {

  struct addrinfo *res0 = NULL, *res = NULL, hints;
  int sock;
  int err;

  TRACE(("enter connect_remote"))

  if (errstring != NULL) {
    *errstring = NULL;
  }

  memset(&hints, 0, sizeof(hints));
  hints.ai_socktype = SOCK_STREAM;
  hints.ai_family = PF_UNSPEC;

  err = getaddrinfo(remotehost, remoteport, &hints, &res0);
  if (err) {
    if (errstring != NULL && *errstring == NULL) {
      int len;
      len = 20 + strlen(gai_strerror(err));
      *errstring = (char*)m_malloc(len);
      snprintf(*errstring, len, "Error resolving: %s", gai_strerror(err));
    }
    TRACE(("Error resolving: %s", gai_strerror(err)))
    return -1;
  }

  sock = -1;
  err = EADDRNOTAVAIL;
  for (res = res0; res; res = res->ai_next) {

    sock = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
    if (sock < 0) {
      err = errno;
      continue;
    }

# if 0 //LUDO:
    if (nonblocking) {
      if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0) {
        close(sock);
        sock = -1;
        if (errstring != NULL && *errstring == NULL) {
          *errstring = m_strdup("Failed non-blocking");
        }
        TRACE(("Failed non-blocking: %s", strerror(errno)))
        continue;
      }
    }
# endif
    if (connect(sock, res->ai_addr, res->ai_addrlen) < 0) {
      if (errno == EINPROGRESS && nonblocking) {
        TRACE(("Connect in progress"))
        break;
      } else {
        err = errno;
        close(sock);
        sock = -1;
        continue;
      }
    }
# if 0 //LUDO:
     //PSP: thanks to XOSs pspvnc :) you guys rock.
    {
      u32 one = 1;
      sceNetInetSetsockopt(sock, IPPROTO_TCP, TCP_NODELAY,(char *)&one, sizeof(one));
      //Alter Socket options to have a timeout
      u32 timeout = 1000; // in microseconds
      err = sceNetInetSetsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, (char*)&timeout, sizeof(timeout));
    }
# endif
    break; /* Success */
  }

  if (sock < 0 && !(errno == EINPROGRESS && nonblocking)) {
    /* Failed */
    if (errstring != NULL && *errstring == NULL) {
      int len;
      len = 20 + strlen(strerror(err));
      *errstring = (char*)m_malloc(len);
      snprintf(*errstring, len, "Error connecting: %s", strerror(err));
    }
    TRACE(("Error connecting: %s", strerror(err)))
  } else {
    /* Success */
    set_sock_priority(sock);
  }

  freeaddrinfo(res0);
  if (sock > 0 && errstring != NULL && *errstring != NULL) {
    m_free(*errstring);
  }

  TRACE(("leave connect_remote: sock %d\n", sock))
  return sock;
}

/* Return a string representation of the socket address passed. The return
 * value is allocated with malloc() */
unsigned char * getaddrstring(struct sockaddr_storage* addr, int withport) 
{
  char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV];
  char *retstring = NULL;
  int ret;
  unsigned int len;

  len = sizeof(struct sockaddr_storage);
  /* Some platforms such as Solaris 8 require that len is the length
   * of the specific structure. */
  if (addr->ss_family == AF_INET) {
    len = sizeof(struct sockaddr_in);
  }
#ifdef AF_INET6
  if (addr->ss_family == AF_INET6) {
    len = sizeof(struct sockaddr_in6);
  }
#endif

  ret = getnameinfo((struct sockaddr*)addr, len, hbuf, sizeof(hbuf), 
      sbuf, sizeof(sbuf), NI_NUMERICSERV | NI_NUMERICHOST);

  if (ret != 0) {
    /* This is a fairly bad failure - it'll fallback to IP if it
     * just can't resolve */
    dropbear_exit("failed lookup (%d, %d)", ret, errno);
  }

  if (withport) {
    len = strlen(hbuf) + 2 + strlen(sbuf);
    retstring = (char*)m_malloc(len);
    snprintf(retstring, len, "%s:%s", hbuf, sbuf);
  } else {
    retstring = m_strdup(hbuf);
  }

  return retstring;

}

/* Get the hostname corresponding to the address addr. On failure, the IP
 * address is returned. The return value is allocated with strdup() */
char* getaddrhostname(struct sockaddr_storage * addr) {

  char hbuf[NI_MAXHOST];
  char sbuf[NI_MAXSERV];
  int ret;
  unsigned int len;
#ifdef DO_HOST_LOOKUP
  const int flags = NI_NUMERICSERV;
#else
  const int flags = NI_NUMERICHOST | NI_NUMERICSERV;
#endif

  len = sizeof(struct sockaddr_storage);
  /* Some platforms such as Solaris 8 require that len is the length
   * of the specific structure. */
  if (addr->ss_family == AF_INET) {
    len = sizeof(struct sockaddr_in);
  }
#ifdef AF_INET6
  if (addr->ss_family == AF_INET6) {
    len = sizeof(struct sockaddr_in6);
  }
#endif


  ret = getnameinfo((struct sockaddr*)addr, len, hbuf, sizeof(hbuf),
      sbuf, sizeof(sbuf), flags);

  if (ret != 0) {
    /* On some systems (Darwin does it) we get EINTR from getnameinfo
     * somehow. Eew. So we'll just return the IP, since that doesn't seem
     * to exhibit that behaviour. */
    return getaddrstring(addr, 0);
  }

  return m_strdup(hbuf);
}

#ifdef DEBUG_TRACE
void printhex(const char * label, const unsigned char * buf, int len) {

  int i;

  fprintf(stderr, "%s\n", label);
  for (i = 0; i < len; i++) {
    fprintf(stderr, "%02x", buf[i]);
    if (i % 16 == 15) {
      fprintf(stderr, "\n");
    }
    else if (i % 2 == 1) {
      fprintf(stderr, " ");
    }
  }
  fprintf(stderr, "\n");
}
#endif

/* Strip all control characters from text (a null-terminated string), except
 * for '\n', '\r' and '\t'.
 * The result returned is a newly allocated string, this must be free()d after
 * use */
char * stripcontrol(const char * text) {

  char * ret;
  int len, pos;
  int i;
  
  len = strlen(text);
  ret = m_malloc(len+1);

  pos = 0;
  for (i = 0; i < len; i++) {
    if ((text[i] <= '~' && text[i] >= ' ') /* normal printable range */
        || text[i] == '\n' || text[i] == '\r' || text[i] == '\t') {
      ret[pos] = text[i];
      pos++;
    }
  }
  ret[pos] = 0x0;
  return ret;
}
      

/* reads the contents of filename into the buffer buf, from the current
 * position, either to the end of the file, or the buffer being full.
 * Returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE */
int buf_readfile(buffer* buf, const char* filename) {

  int fd;
  int len;
  int maxlen;

  fd = open(filename, O_RDONLY);

  if (fd < 0) {
    close(fd);
    return DROPBEAR_FAILURE;
  }
  
  do {
    maxlen = buf->size - buf->pos;
    len = read(fd, buf_getwriteptr(buf, maxlen),
        maxlen);
    buf_incrwritepos(buf, len);
  } while (len < maxlen && len > 0);

  close(fd);
  return DROPBEAR_SUCCESS;
}

/* get a line from the file into buffer in the style expected for an
 * authkeys file.
 * Will return DROPBEAR_SUCCESS if data is read, or DROPBEAR_FAILURE on EOF.*/
/* Only used for ~/.ssh/known_hosts and ~/.ssh/authorized_keys */
#if defined(DROPBEAR_CLIENT) || defined(ENABLE_SVR_PUBKEY_AUTH)
int buf_getline(buffer * line, FILE * authfile) {

  int c = EOF;

  TRACE(("enter buf_getline"))

  buf_setpos(line, 0);
  buf_setlen(line, 0);

  while (line->pos < line->size) {

    c = fgetc(authfile); /*getc() is weird with some uClibc systems*/
    if (c == EOF || c == '\n' || c == '\r') {
      goto out;
    }

    buf_putbyte(line, (unsigned char)c);
  }

  TRACE(("leave getauthline: line too long"))
  /* We return success, but the line length will be zeroed - ie we just
   * ignore that line */
  buf_setlen(line, 0);

out:


  /* if we didn't read anything before EOF or error, exit */
  if (c == EOF && line->pos == 0) {
    TRACE(("leave buf_getline: failure"))
    return DROPBEAR_FAILURE;
  } else {
    TRACE(("leave buf_getline: success"))
    buf_setpos(line, 0);
    return DROPBEAR_SUCCESS;
  }

}  
#endif

/* make sure that the socket closes */
void m_close(int fd) {

  int val;
  do {
    val = close(fd);
  } while (val < 0 && errno == EINTR);

  if (val < 0 && errno != EBADF) {
    /* Linux says EIO can happen */
    dropbear_exit("Error closing fd %d, %s", fd, strerror(errno));
  }
}
  
void * m_malloc(size_t size) {

  void* ret;

  if (size == 0) {
    dropbear_exit("m_malloc failed");
  }
  ret = calloc(1, size);
  if (ret == NULL) {
    dropbear_exit("m_malloc failed");
  }
  return ret;

}

void * m_strdup(const char * str) {
  char* ret;

  ret = strdup(str);
  if (ret == NULL) {
    dropbear_exit("m_strdup failed");
  }
  return ret;
}

void __m_free(void* ptr) {
  if (ptr != NULL) {
    free(ptr);
  }
}

void * m_realloc(void* ptr, size_t size) {

  void *ret;

  if (size == 0) {
    dropbear_exit("m_realloc failed");
  }
  ret = realloc(ptr, size);
  if (ret == NULL) {
    dropbear_exit("m_realloc failed");
  }
  return ret;
}

/* Clear the data, based on the method in David Wheeler's
 * "Secure Programming for Linux and Unix HOWTO" */
/* Beware of calling this from within dbutil.c - things might get
 * optimised away */
void m_burn(void *data, unsigned int len) 
{
# if 0 //LUDO:
  volatile char *p = data;

  if (data == NULL)
    return;
  while (len--) {
    *p++ = 0x66;
  }
# endif
}


void setnonblocking(int fd) {
# if 0 //LUDO: TO_BE_DONE !
  TRACE(("setnonblocking: %d", fd))

  if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0) {
    if (errno == ENODEV) {
      /* Some devices (like /dev/null redirected in)
       * can't be set to non-blocking */
      TRACE(("ignoring ENODEV for setnonblocking"))
    } else {
      dropbear_exit("Couldn't set nonblocking");
    }
  }
  TRACE(("leave setnonblocking"))
# endif
}
