path: root/src/vppinfra/format.c

/*
 * Copyright (c) 2015 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*------------------------------------------------------------------
 * format.c -- see notice below
 *
 * October 2003, Eliot Dresselhaus
 *
 * Modifications to this file Copyright (c) 2003 by cisco Systems, Inc.
 * All rights reserved.
 *------------------------------------------------------------------
 */

/*
  Copyright (c) 2001, 2002, 2003, 2006 Eliot Dresselhaus

  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.
*/

#include <stdarg.h>		/* va_start, etc */

#ifdef CLIB_UNIX
#include <unistd.h>
#include <stdio.h>
#endif

#ifdef CLIB_STANDALONE
#include <vppinfra/standalone_stdio.h>
#endif

#include <vppinfra/mem.h>
#include <vppinfra/format.h>
#include <vppinfra/vec.h>
#include <vppinfra/error.h>
#include <vppinfra/string.h>
#include <vppinfra/os.h>	/* os_puts */
#include <vppinfra/math.h>

typedef struct
{
  /* Output number in this base. */
  u8 base;

  /* Number of show of 64 bit number. */
  u8 n_bits;

  /* Signed or unsigned. */
  u8 is_signed;

  /* Output digits uppercase (not lowercase) %X versus %x. */
  u8 uppercase_digits;
} format_integer_options_t;

static u8 *format_integer (u8 * s, u64 number,
			   format_integer_options_t * options);
static u8 *format_float (u8 * s, f64 x, uword n_digits_to_print,
			 uword output_style);

typedef struct
{
  /* String justification: + => right, - => left, = => center. */
  uword justify;

  /* Width of string (before and after decimal point for numbers).
     0 => natural width. */
  uword width[2];

  /* Long => 'l', long long 'L', int 0. */
  uword how_long;

  /* Pad character.  Defaults to space. */
  uword pad_char;
} format_info_t;

static u8 *
justify (u8 * s, format_info_t * fi, uword s_len_orig)
{
  uword i0, l0, l1;

  i0 = s_len_orig;
  l0 = i0 + fi->width[0];
  l1 = vec_len (s);

  /* If width is zero user returned width. */
  if (l0 == i0)
    l0 = l1;

  if (l1 > l0)
    _vec_len (s) = l0;
  else if (l0 > l1)
    {
      uword n = l0 - l1;
      uword n_left = 0, n_right = 0;

      switch (fi->justify)
	{
	case '-':
	  n_right = n;
	  break;

	case '+':
	  n_left = n;
	  break;

	case '=':
	  n_right = n_left = n / 2;
	  if (n % 2)
	    n_left++;
	  break;
	}
      if (n_left > 0)
	{
	  vec_insert (s, n_left, i0);
	  memset (s + i0, fi->pad_char, n_left);
	  l1 = vec_len (s);
	}
      if (n_right > 0)
	{
	  vec_resize (s, n_right);
	  memset (s + l1, fi->pad_char, n_right);
	}
    }
  return s;
}

static const u8 *
do_percent (u8 ** _s, const u8 * fmt, va_list * va)
{
  u8 *s = *_s;
  uword c;

  const u8 *f = fmt;

  format_info_t fi = {
    .justify = '+',
    .width = {0},
    .pad_char = ' ',
    .how_long = 0,
  };

  uword i;

  ASSERT (f[0] == '%');

  switch (c = *++f)
    {
    case '%':
      /* %% => % */
      vec_add1 (s, c);
      f++;
      goto done;

    case '-':
    case '+':
    case '=':
      fi.justify = c;
      c = *++f;
      break;
    }

  /* Parse width0 . width1. */
  {
    uword is_first_digit = 1;

    fi.width[0] = fi.width[1] = 0;
    for (i = 0; i < 2; i++)
      {
	if (c == '0' && i == 0 && is_first_digit)
	  fi.pad_char = '0';
	is_first_digit = 0;
	if (c == '*')
	  {
	    fi.width[i] = va_arg (*va, int);
	    c = *++f;
	  }
	else
	  {
	    while (c >= '0' && c <= '9')
	      {
		fi.width[i] = 10 * fi.width[i] + (c - '0');
		c = *++f;
	      }
	  }
	if (c != '.')
	  break;
	c = *++f;
      }
  }

  /* Parse %l* and %L* */
  switch (c)
    {
    case 'w':
      /* word format. */
      fi.how_long = 'w';
      c = *++f;
      break;

    case 'L':
    case 'l':
      fi.how_long = c;
      c = *++f;
      if (c == 'l' && *f == 'l')
	{
	  fi.how_long = 'L';
	  c = *++f;
	}
      break;
    }

  /* Finally we are ready for format letter. */
  if (c != 0)
    {
      uword s_initial_len = vec_len (s);
      format_integer_options_t o = {
	.is_signed = 0,
	.base = 10,
	.n_bits = BITS (uword),
	.uppercase_digits = 0,
      };

      f++;

      switch (c)
	{
	default:
	  {
	    /* Try to give a helpful error message. */
	    vec_free (s);
	    s = format (s, "**** CLIB unknown format `%%%c' ****", c);
	    goto done;
	  }

	case 'c':
	  vec_add1 (s, va_arg (*va, int));
	  break;

	case 'p':
	  vec_add1 (s, '0');
	  vec_add1 (s, 'x');

	  o.is_signed = 0;
	  o.n_bits = BITS (uword *);
	  o.base = 16;
	  o.uppercase_digits = 0;

	  s = format_integer (s, pointer_to_uword (va_arg (*va, void *)), &o);
	  break;

	case 'x':
	case 'X':
	case 'u':
	case 'd':
	  {
	    u64 number;

	    o.base = 10;
	    if (c == 'x' || c == 'X')
	      o.base = 16;
	    o.is_signed = c == 'd';
	    o.uppercase_digits = c == 'X';

	    switch (fi.how_long)
	      {
	      case 'L':
		number = va_arg (*va, unsigned long long);
		o.n_bits = BITS (unsigned long long);
		break;

	      case 'l':
		number = va_arg (*va, long);
		o.n_bits = BITS (long);
		break;

	      case 'w':
		number = va_arg (*va, word);
		o.n_bits = BITS (uword);
		break;

	      default:
		number = va_arg (*va, int);
		o.n_bits = BITS (int);
		break;
	      }

	    s = format_integer (s, number, &o);
	  }
	  break;

	case 's':
	case 'S':
	  {
	    char *cstring = va_arg (*va, char *);
	    uword len;

	    if (!cstring)
	      {
		cstring = "(nil)";
		len = 5;
	      }
	    else if (fi.width[1] != 0)
	      len = clib_min (strlen (cstring), fi.width[1]);
	    else
	      len = strlen (cstring);

	    /* %S => format string as C identifier (replace _ with space). */
	    if (c == 'S')
	      {
		for (i = 0; i < len; i++)
		  vec_add1 (s, cstring[i] == '_' ? ' ' : cstring[i]);
	      }
	    else
	      vec_add (s, cstring, len);
	  }
	  break;

	case 'v':
	  {
	    u8 *v = va_arg (*va, u8 *);
	    uword len;

	    if (fi.width[1] != 0)
	      len = clib_min (vec_len (v), fi.width[1]);
	    else
	      len = vec_len (v);

	    vec_add (s, v, len);
	  }
	  break;

	case 'f':
	case 'g':
	case 'e':
	  /* Floating point. */
	  ASSERT (fi.how_long == 0 || fi.how_long == 'l');
	  s = format_float (s, va_arg (*va, double), fi.width[1], c);
	  break;

	case 'U':
	  /* User defined function. */
	  {
	    typedef u8 *(user_func_t) (u8 * s, va_list * args);
	    user_func_t *u = va_arg (*va, user_func_t *);

	    s = (*u) (s, va);
	  }
	  break;
	}

      s = justify (s, &fi, s_initial_len);
    }

done:
  *_s = s;
  return f;
}

u8 *
va_format (u8 * s, const char *fmt, va_list * va)
{
  const u8 *f = (u8 *) fmt, *g;
  u8 c;

  g = f;
  while (1)
    {
      c = *f;

      if (!c)
	break;

      if (c == '%')
	{
	  if (f > g)
	    vec_add (s, g, f - g);
	  f = g = do_percent (&s, f, va);
	}
      else
	{
	  f++;
	}
    }

  if (f > g)
    vec_add (s, g, f - g);

  return s;
}

u8 *
format (u8 * s, const char *fmt, ...)
{
  va_list va;
  va_start (va, fmt);
  s = va_format (s, fmt, &va);
  va_end (va);
  return s;
}

word
va_fformat (FILE * f, char *fmt, va_list * va)
{
  word ret;
  u8 *s;

  s = va_format (0, fmt, va);

#ifdef CLIB_UNIX
  if (f)
    {
      ret = fwrite (s, vec_len (s), 1, f);
    }
  else
#endif /* CLIB_UNIX */
    {
      ret = 0;
      os_puts (s, vec_len (s), /* is_error */ 0);
    }

  vec_free (s);
  return ret;
}

word
fformat (FILE * f, char *fmt, ...)
{
  va_list va;
  word ret;

  va_start (va, fmt);
  ret = va_fformat (f, fmt, &va);
  va_end (va);

  return (ret);
}

#ifdef CLIB_UNIX
word
fdformat (int fd, char *fmt, ...)
{
  word ret;
  u8 *s;
  va_list va;

  va_start (va, fmt);
  s = va_format (0, fmt, &va);
  va_end (va);

  ret = write (fd, s, vec_len (s));
  vec_free (s);
  return ret;
}
#endif

/* Format integral type. */
static u8 *
format_integer (u8 * s, u64 number, format_integer_options_t * options)
{
  u64 q;
  u32 r;
  u8 digit_buffer[128];
  u8 *d = digit_buffer + sizeof (digit_buffer);
  word c, base;

  if (options->is_signed && (i64) number < 0)
    {
      number = -number;
      vec_add1 (
/*
 * Copyright (c) 2016 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <vnet/tcp/tcp.h>
#include <vnet/lisp-cp/packets.h>
#include <math.h>

vlib_node_registration_t tcp4_output_node;
vlib_node_registration_t tcp6_output_node;

typedef enum _tcp_output_next
{
  TCP_OUTPUT_NEXT_DROP,
  TCP_OUTPUT_NEXT_IP_LOOKUP,
  TCP_OUTPUT_NEXT_IP_REWRITE,
  TCP_OUTPUT_NEXT_IP_ARP,
  TCP_OUTPUT_N_NEXT
} tcp_output_next_t;

#define foreach_tcp4_output_next              	\
  _ (DROP, "error-drop")                        \
  _ (IP_LOOKUP, "ip4-lookup")			\
  _ (IP_REWRITE, "ip4-rewrite")			\
  _ (IP_ARP, "ip4-arp")

#define foreach_tcp6_output_next              	\
  _ (DROP, "error-drop")                        \
  _ (IP_LOOKUP, "ip6-lookup")			\
  _ (IP_REWRITE, "ip6-rewrite")			\
  _ (IP_ARP, "ip6-discover-neighbor")

static char *tcp_error_strings[] = {
#define tcp_error(n,s) s,
#include <vnet/tcp/tcp_error.def>
#undef tcp_error
};

typedef struct
{
  tcp_header_t tcp_header;
  tcp_connection_t tcp_connection;
} tcp_tx_trace_t;

u16 dummy_mtu = 1460;

u8 *
format_tcp_tx_trace (u8 * s, va_list * args)
{
  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  tcp_tx_trace_t *t = va_arg (*args, tcp_tx_trace_t *);
  u32 indent = format_get_indent (s);

  s = format (s, "%U\n%U%U",
	      format_tcp_header, &t->tcp_header, 128,
	      format_white_space, indent,
	      format_tcp_connection, &t->tcp_connection, 1);

  return s;
}

static u8
tcp_window_compute_scale (u32 window)
{
  u8 wnd_scale = 0;
  while (wnd_scale < TCP_MAX_WND_SCALE && (window >> wnd_scale) > TCP_WND_MAX)
    wnd_scale++;
  return wnd_scale;
}

/**
 * Update max segment size we're able to process.
 *
 * The value is constrained by our interface's MTU and IP options. It is
 * also what we advertise to our peer.
 */
void
tcp_update_rcv_mss (tcp_connection_t * tc)
{
  /* TODO find our iface MTU */
  tc->mss = dummy_mtu - sizeof (tcp_header_t);
}

/**
 * TCP's initial window
 */
always_inline u32
tcp_initial_wnd_unscaled (tcp_connection_t * tc)
{
  /* RFC 6928 recommends the value lower. However at the time our connections
   * are initialized, fifos may not be allocated. Therefore, advertise the
   * smallest possible unscaled window size and update once fifos are
   * assigned to the session.
   */
  /*
     tcp_update_rcv_mss (tc);
     TCP_IW_N_SEGMENTS * tc->mss;
   */
  return TCP_MIN_RX_FIFO_SIZE;
}

/**
 * Compute initial window and scale factor. As per RFC1323, window field in
 * SYN and SYN-ACK segments is never scaled.
 */
u32
tcp_initial_window_to_advertise (tcp_connection_t * tc)
{
  u32 max_fifo;

  /* Initial wnd for SYN. Fifos are not allocated yet.
   * Use some predefined value. For SYN-ACK we still want the
   * scale to be computed in the same way */
  max_fifo = TCP_MAX_RX_FIFO_SIZE;

  tc->rcv_wscale = tcp_window_compute_scale (max_fifo);
  tc->rcv_wnd = tcp_initial_wnd_unscaled (tc);

  return clib_min (tc->rcv_wnd, TCP_WND_MAX);
}

/**
 * Compute and return window to advertise, scaled as per RFC1323
 */
u32
tcp_window_to_advertise (tcp_connection_t * tc, tcp_state_t state)
{
  if (state < TCP_STATE_ESTABLISHED)
    return tcp_initial_window_to_advertise (tc);

  tcp_update_rcv_wnd (tc);

  if (tc->rcv_wnd == 0)
    {
      tc->flags |= TCP_CONN_SENT_RCV_WND0;
    }
  else
    {
      tc->flags &= ~TCP_CONN_SENT_RCV_WND0;
    }

  return tc->rcv_wnd >> tc->rcv_wscale;
}

void
tcp_update_rcv_wnd (tcp_connection_t * tc)
{
  i32 observed_wnd;
  u32 available_space, max_fifo, wnd;

  /*
   * Figure out how much space we have available
   */
  available_space = transport_max_rx_enqueue (&tc->connection);
  max_fifo = transport_rx_fifo_size (&tc->connection);

  ASSERT (tc->rcv_opts.mss < max_fifo);
  if (available_space < tc->rcv_opts.mss && available_space < max_fifo >> 3)
    available_space = 0;

  /*
   * Use the above and what we know about what we've previously advertised
   * to compute the new window
   */
  observed_wnd = (i32) tc->rcv_wnd - (tc->rcv_nxt - tc->rcv_las);
  if (observed_wnd < 0)
    observed_wnd = 0;

  /* Bad. Thou shalt not shrink */
  if (available_space < observed_wnd)
    {
      wnd = observed_wnd;
      TCP_EVT_DBG (TCP_EVT_RCV_WND_SHRUNK, tc, observed_wnd, available_space);
    }
  else
    {
      wnd = available_space;
    }

  /* Make sure we have a multiple of rcv_wscale */
  if (wnd && tc->rcv_wscale)
    {
      wnd &= ~(1 << tc->rcv_wscale);
      if (wnd == 0)
	wnd = 1 << tc->rcv_wscale;
    }

  tc->rcv_wnd = clib_min (wnd, TCP_WND_MAX << tc->rcv_wscale);
}

/**
 * Write TCP options to segment.
 */
u32
tcp_options_write (u8 * data, tcp_options_t * opts)
{
  u32 opts_len = 0;
  u32 buf, seq_len = 4;

  if (tcp_opts_mss (opts))
    {
      *data++ = TCP_OPTION_MSS;
      *data++ = TCP_OPTION_LEN_MSS;
      buf = clib_host_to_net_u16 (opts->mss);
      clib_memcpy (data, &buf, sizeof (opts->mss));
      data += sizeof (opts->mss);
      opts_len += TCP_OPTION_LEN_MSS;
    }

  if (tcp_opts_wscale (opts))
    {
      *data++ = TCP_OPTION_WINDOW_SCALE;
      *data++ = TCP_OPTION_LEN_WINDOW_SCALE;
      *data++ = opts->wscale;
      opts_len += TCP_OPTION_LEN_WINDOW_SCALE;
    }

  if (tcp_opts_sack_permitted (opts))
    {
      *data++ = TCP_OPTION_SACK_PERMITTED;
      *data++ = TCP_OPTION_LEN_SACK_PERMITTED;
      opts_len += TCP_OPTION_LEN_SACK_PERMITTED;
    }

  if (tcp_opts_tstamp (opts))
    {
      *data++ = TCP_OPTION_TIMESTAMP;
      *data++ = TCP_OPTION_LEN_TIMESTAMP;
      buf = clib_host_to_net_u32 (opts->tsval);
      clib_memcpy (data, &buf, sizeof (opts->tsval));
      data += sizeof (opts->tsval);
      buf = clib_host_to_net_u32 (opts->tsecr);
      clib_memcpy (data, &buf, sizeof (opts->tsecr));
      data += sizeof (opts->tsecr);
      opts_len += TCP_OPTION_LEN_TIMESTAMP;
    }

  if (tcp_opts_sack (opts))
    {
      int i;
      u32 n_sack_blocks = clib_min (vec_len (opts->sacks),
				    TCP_OPTS_MAX_SACK_BLOCKS);

      if (n_sack_blocks != 0)
	{
	  *data++ = TCP_OPTION_SACK_BLOCK;
	  *data++ = 2 + n_sack_blocks * TCP_OPTION_LEN_SACK_BLOCK;
	  for (i = 0; i < n_sack_blocks; i++)
	    {
	      buf = clib_host_to_net_u32 (opts->sacks[i].start);
	      clib_memcpy (data, &buf, seq_len);
	      data += seq_len;
	      buf = clib_host_to_net_u32 (opts->sacks[i].end);
	      clib_memcpy (data, &buf, seq_len);
	      data += seq_len;
	    }
	  opts_len += 2 + n_sack_blocks * TCP_OPTION_LEN_SACK_BLOCK;
	}
    }

  /* Terminate TCP options */
  if (opts_len % 4)
    {
      *data++ = TCP_OPTION_EOL;
      opts_len += TCP_OPTION_LEN_EOL;
    }

  /* Pad with zeroes to a u32 boundary */
  while (opts_len % 4)
    {
      *data++ = TCP_OPTION_NOOP;
      opts_len += TCP_OPTION_LEN_NOOP;
    }
  return opts_len;
}

always_inline int
tcp_make_syn_options (tcp_options_t * opts, u8 wnd_scale)
{
  u8 len = 0;

  opts->flags |= TCP_OPTS_FLAG_MSS;
  opts->mss = dummy_mtu;	/*XXX discover that */
  len += TCP_OPTION_LEN_MSS;

  opts->flags |= TCP_OPTS_FLAG_WSCALE;
  opts->wscale = wnd_scale;
  len += TCP_OPTION_LEN_WINDOW_SCALE;

  opts->flags |= TCP_OPTS_FLAG_TSTAMP;
  opts->tsval = tcp_time_now ();
  opts->tsecr = 0;
  len += TCP_OPTION_LEN_TIMESTAMP;

  if (TCP_USE_SACKS)
    {
      opts->flags |= TCP_OPTS_FLAG_SACK_PERMITTED;
      len += TCP_OPTION_LEN_SACK_PERMITTED;
    }

  /* Align to needed boundary */
  len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN;
  return len;
}

always_inline int
tcp_make_synack_options (tcp_connection_t * tc,