tls_picotls.c

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#include <math.h>

#include "certs.h"
#include "tls_picotls.h"
#include "pico_vpp_crypto.h"

picotls_main_t picotls_main;

#define MAX_QUEUE 12000
#define PTLS_MAX_PLAINTEXT_RECORD_SIZE 16384

static u32
picotls_ctx_alloc (void)
{
  u8 thread_id = vlib_get_thread_index ();
  picotls_main_t *pm = &picotls_main;
  picotls_ctx_t **ctx;

  pool_get (pm->ctx_pool[thread_id], ctx);
  if (!(*ctx))
    *ctx = clib_mem_alloc (sizeof (picotls_ctx_t));

  clib_memset (*ctx, 0, sizeof (picotls_ctx_t));
  (*ctx)->ctx.c_thread_index = thread_id;
  (*ctx)->ctx.tls_ctx_engine = CRYPTO_ENGINE_PICOTLS;
  (*ctx)->ctx.app_session_handle = SESSION_INVALID_HANDLE;
  (*ctx)->ptls_ctx_idx = ctx - pm->ctx_pool[thread_id];
  return (*ctx)->ptls_ctx_idx;
}

static void
picotls_ctx_free (tls_ctx_t * ctx)
{
  picotls_ctx_t *ptls_ctx = (picotls_ctx_t *) ctx;
  vec_free (ptls_ctx->rx_content);
  vec_free (ptls_ctx->write_content);
  pool_put_index (picotls_main.ctx_pool[ctx->c_thread_index],
                  ptls_ctx->ptls_ctx_idx);
}

static u32
picotls_listen_ctx_alloc (void)
{
  picotls_main_t *pm = &picotls_main;
  picotls_listen_ctx_t *ptls_lctx;

  pool_get (pm->lctx_pool, ptls_lctx);

  clib_memset (ptls_lctx, 0, sizeof (picotls_listen_ctx_t));
  ptls_lctx->ptls_lctx_index = ptls_lctx - pm->lctx_pool;
  return ptls_lctx->ptls_lctx_index;
}

static void
picotls_listen_ctx_free (picotls_listen_ctx_t * lctx)
{
  pool_put_index (picotls_main.lctx_pool, lctx->ptls_lctx_index);
}

tls_ctx_t *
picotls_ctx_get (u32 ctx_index)
{
  picotls_ctx_t **ctx;
  ctx =
    pool_elt_at_index (picotls_main.ctx_pool[vlib_get_thread_index ()],
                       ctx_index);
  return &(*ctx)->ctx;
}

picotls_listen_ctx_t *
picotls_lctx_get (u32 lctx_index)
{
  return pool_elt_at_index (picotls_main.lctx_pool, lctx_index);
}

static u8
picotls_handshake_is_over (tls_ctx_t * ctx)
{
  picotls_ctx_t *ptls_ctx = (picotls_ctx_t *) ctx;
  assert (ptls_ctx->tls);
  return ptls_handshake_is_complete (ptls_ctx->tls);
}

static int
picotls_try_handshake_write (picotls_ctx_t * ptls_ctx,
                             session_t * tls_session, ptls_buffer_t * buf)
{
  u32 enq_max, enq_now;
  svm_fifo_t *f;
  int write, buf_left;

  if (buf->off <= 0)
    return 0;

  f = tls_session->tx_fifo;
  buf_left = buf->off;
  enq_max = svm_fifo_max_enqueue_prod (f);
  if (!enq_max)
    return 0;

  enq_now = clib_min (svm_fifo_max_write_chunk (f), enq_max);
  enq_now = clib_min (enq_now, buf_left);
  write = svm_fifo_enqueue (f, enq_now, buf->base);
  buf_left -= write;
  tls_add_vpp_q_tx_evt (tls_session);
  return write;
}

static int
picotls_start_listen (tls_ctx_t * lctx)
{
  picotls_listen_ctx_t *ptls_lctx;
  ptls_context_t *ptls_ctx;
  u32 ptls_lctx_idx;
  app_cert_key_pair_t *ckpair;
  static ptls_key_exchange_algorithm_t *key_exchange[] = {
#ifdef PTLS_OPENSSL_HAVE_X25519
    &ptls_openssl_x25519,
#endif
#ifdef PTLS_OPENSSL_HAVE_SECP256r1
    &ptls_openssl_secp256r1,
#endif
#ifdef PTLS_OPENSSL_HAVE_SECP384r1
    &ptls_openssl_secp384r1,
#endif
#ifdef PTLS_OPENSSL_HAVE_SECP521r1
    &ptls_openssl_secp521r1
#endif
  };

  ckpair = app_cert_key_pair_get_if_valid (lctx->ckpair_index);
  if (!ckpair || !ckpair->cert || !ckpair->key)
    {
      TLS_DBG (1, "tls cert and/or key not configured %d",
               lctx->parent_app_wrk_index);
      return -1;
    }

  ptls_lctx_idx = picotls_listen_ctx_alloc ();
  ptls_lctx = picotls_lctx_get (ptls_lctx_idx);
  ptls_ctx = malloc (sizeof (ptls_context_t));
  ptls_lctx->ptls_ctx = ptls_ctx;

  memset (ptls_ctx, 0, sizeof (ptls_context_t));
  ptls_ctx->update_open_count = NULL;

  /*
   * Process certificate & private key.
   */
  load_bio_certificate_chain (ptls_ctx, (char *) ckpair->cert);
  load_bio_private_key (ptls_ctx, (char *) ckpair->key);

  /* setup protocol related functions */
  ptls_ctx->key_exchanges = key_exchange;
  ptls_ctx->random_bytes = ptls_openssl_random_bytes;
  ptls_ctx->cipher_suites = ptls_vpp_crypto_cipher_suites;
  ptls_ctx->get_time = &ptls_get_time;

  lctx->tls_ssl_ctx = ptls_lctx_idx;

  return 0;
}

static int
picotls_stop_listen (tls_ctx_t * lctx)
{
  u32 ptls_lctx_index;
  picotls_listen_ctx_t *ptls_lctx;

  ptls_lctx_index = lctx->tls_ssl_ctx;
  ptls_lctx = picotls_lctx_get (ptls_lctx_index);

  picotls_listen_ctx_free (ptls_lctx);

  return 0;
}

static void
picotls_handle_handshake_failure (tls_ctx_t * ctx)
{
  session_free (session_get (ctx->c_s_index, ctx->c_thread_index));
  ctx->no_app_session = 1;
  ctx->c_s_index = SESSION_INVALID_INDEX;
  tls_disconnect_transport (ctx);
}

static void
picotls_confirm_app_close (tls_ctx_t * ctx)
{
  tls_disconnect_transport (ctx);
  session_transport_closed_notify (&ctx->connection);
}

static int
picotls_transport_close (tls_ctx_t * ctx)
{
  if (!picotls_handshake_is_over (ctx))
    {
      picotls_handle_handshake_failure (ctx);
      return 0;
    }
  picotls_ctx_t *ptls_ctx = (picotls_ctx_t *) ctx;
  ptls_free (ptls_ctx->tls);
  session_transport_closing_notify (&ctx->connection);
  return 0;
}

static int
picotls_app_close (tls_ctx_t * ctx)
{
  session_t *app_session;

  app_session = session_get_from_handle (ctx->app_session_handle);
  if (!svm_fifo_max_dequeue_cons (app_session->tx_fifo))
    picotls_confirm_app_close (ctx);
  else
    ctx->app_closed = 1;

  return 0;
}

static inline int
picotls_do_handshake (picotls_ctx_t * ptls_ctx, session_t * tls_session,
                      u8 * input, int input_len)
{
  ptls_t *tls = ptls_ctx->tls;
  ptls_buffer_t buf;
  int rv = PTLS_ERROR_IN_PROGRESS;
  int write = 0, off;

  do
    {
      off = 0;
      do
        {
          ptls_buffer_init (&buf, "", 0);
          size_t consumed = input_len - off;
          rv = ptls_handshake (tls, &buf, input + off, &consumed, NULL);
          off += consumed;
          ptls_ctx->rx_offset += consumed;
          if ((rv == 0 || rv == PTLS_ERROR_IN_PROGRESS) && buf.off != 0)
            {
              write = picotls_try_handshake_write (ptls_ctx, tls_session,
                                                   &buf);
            }
          ptls_buffer_dispose (&buf);
        }
      while (rv == PTLS_ERROR_IN_PROGRESS && input_len != off);
    }
  while (rv == PTLS_ERROR_IN_PROGRESS);

  return write;
}

static inline int
picotls_ctx_read (tls_ctx_t * ctx, session_t * tls_session)
{
  picotls_ctx_t *ptls_ctx = (picotls_ctx_t *) ctx;
  int from_tls_len = 0, off, crypto_len, ret;
  u32 deq_max, deq_now;
  u32 enq_max;
  ptls_buffer_t *buf = &ptls_ctx->read_buffer;
  svm_fifo_t *tls_rx_fifo, *app_rx_fifo;
  session_t *app_session;

  tls_rx_fifo = tls_session->rx_fifo;

  if (!picotls_handshake_is_over (ctx))
    {
      deq_max = svm_fifo_max_dequeue_cons (tls_rx_fifo);
      if (!deq_max)
        goto done_hs;

      vec_validate (ptls_ctx->rx_content, deq_max);
      ptls_ctx->rx_offset = 0;
      ptls_ctx->rx_len = 0;

      off = svm_fifo_dequeue (tls_rx_fifo, deq_max, TLS_RX_LEN (ptls_ctx));
      from_tls_len += off;
      ptls_ctx->rx_len += off;

      picotls_do_handshake (ptls_ctx, tls_session, TLS_RX_OFFSET (ptls_ctx),
                            from_tls_len);
      if (picotls_handshake_is_over (ctx))
        tls_notify_app_accept (ctx);

    done_hs:
      if (!TLS_RX_IS_LEFT (ptls_ctx))
        return 0;
    }

  app_session = session_get_from_handle (ctx->app_session_handle);
  app_rx_fifo = app_session->rx_fifo;

  if (TLS_READ_IS_LEFT (ptls_ctx))
    goto enq_buf;

  ptls_buffer_init (buf, "", 0);
  ptls_ctx->read_buffer_offset = 0;

  if (!TLS_RX_IS_LEFT (ptls_ctx))
    {
      deq_max = svm_fifo_max_dequeue_cons (tls_rx_fifo);
      if (!deq_max)
        goto app_fifo;

      deq_now = clib_min (deq_max, svm_fifo_max_read_chunk (tls_rx_fifo));

      if (PREDICT_FALSE (deq_now < deq_max))
        {
          off =
            svm_fifo_dequeue (tls_rx_fifo, deq_max, TLS_RX_LEN (ptls_ctx));
          from_tls_len += off;
          ptls_ctx->rx_len += off;
        }
      else
        {
          ret =
            ptls_receive (ptls_ctx->tls, buf, svm_fifo_head (tls_rx_fifo),
                          (size_t *) & deq_now);
          svm_fifo_dequeue_drop (tls_rx_fifo, deq_now);
          goto enq_buf;
        }
    }

app_fifo:

  enq_max = svm_fifo_max_enqueue_prod (app_rx_fifo);
  if (!enq_max)
    goto final;

  crypto_len = clib_min (enq_max, TLS_RX_LEFT_LEN (ptls_ctx));
  off = 0;

  do
    {
      size_t consumed = crypto_len - off;
      ret =
        ptls_receive (ptls_ctx->tls, buf,
                      TLS_RX_OFFSET (ptls_ctx), &consumed);
      off += consumed;
      ptls_ctx->rx_offset += off;
    }
  while (ret == 0 && off < crypto_len);

enq_buf:

  off =
    svm_fifo_enqueue (app_rx_fifo, TLS_READ_LEFT_LEN (ptls_ctx),
                      TLS_READ_OFFSET (ptls_ctx));
  if (off < 0)
    {
      tls_add_vpp_q_builtin_rx_evt (tls_session);
      return 0;
    }

  ptls_ctx->read_buffer_offset += off;
  if (!TLS_RX_IS_LEFT (ptls_ctx))
    {
      ptls_ctx->rx_len = 0;
      ptls_ctx->rx_offset = 0;
    }

final:
  ptls_buffer_dispose (buf);

  if (app_session->session_state >= SESSION_STATE_READY)
    tls_notify_app_enqueue (ctx, app_session);

  if (TLS_RX_IS_LEFT (ptls_ctx) || TLS_READ_IS_LEFT (ptls_ctx)
      || svm_fifo_max_dequeue (tls_rx_fifo))
    tls_add_vpp_q_builtin_rx_evt (tls_session);

  return from_tls_len;
}

static inline int
picotls_content_process (picotls_ctx_t * ptls_ctx, svm_fifo_t * src_fifo,
                         svm_fifo_t * dst_fifo, int content_len,
                         int total_record_overhead, int is_no_copy)
{
  ptls_buffer_t *buf = &ptls_ctx->write_buffer;
  int total_length = content_len + total_record_overhead;
  int to_dst_len;
  if (is_no_copy)
    {
      ptls_buffer_init (buf, svm_fifo_tail (dst_fifo), total_length);
      ptls_send (ptls_ctx->tls, buf, svm_fifo_head (src_fifo), content_len);

      assert (!buf->is_allocated);
      assert (buf->base == svm_fifo_tail (dst_fifo));

      svm_fifo_dequeue_drop (src_fifo, content_len);
      svm_fifo_enqueue_nocopy (dst_fifo, buf->off);
      to_dst_len = buf->off;
    }
  else
    {
      assert (!TLS_WRITE_IS_LEFT (ptls_ctx));
      vec_validate (ptls_ctx->write_content, total_length);
      ptls_buffer_init (buf, ptls_ctx->write_content, total_length);

      ptls_send (ptls_ctx->tls, buf, svm_fifo_head (src_fifo), content_len);
      svm_fifo_dequeue_drop (src_fifo, content_len);

      to_dst_len = svm_fifo_enqueue (dst_fifo, buf->off, buf->base);
    }
  ptls_ctx->write_buffer_offset += to_dst_len;
  return to_dst_len;
}

static inline int
picotls_ctx_write (tls_ctx_t * ctx, session_t * app_session,
                   transport_send_params_t * sp)
{
  picotls_ctx_t *ptls_ctx = (picotls_ctx_t *) ctx;
  u32 deq_max, deq_now;
  u32 enq_max, enq_now;
  int from_app_len = 0, to_tls_len = 0, is_nocopy = 0;
  svm_fifo_t *tls_tx_fifo, *app_tx_fifo;
  session_t *tls_session;

  int record_overhead = ptls_get_record_overhead (ptls_ctx->tls);
  int num_records, total_overhead;

  tls_session = session_get_from_handle (ctx->tls_session_handle);
  tls_tx_fifo = tls_session->tx_fifo;
  app_tx_fifo = app_session->tx_fifo;

  if (PREDICT_FALSE (TLS_WRITE_IS_LEFT (ptls_ctx)))
    {
      enq_max = svm_fifo_max_enqueue_prod (tls_tx_fifo);
      int to_write = clib_min (enq_max,
                               ptls_ctx->write_buffer.off -
                               ptls_ctx->write_buffer_offset);
      to_tls_len =
        svm_fifo_enqueue (tls_tx_fifo, to_write, TLS_WRITE_OFFSET (ptls_ctx));
      if (to_tls_len < 0)
        {
          app_session->flags |= SESSION_F_CUSTOM_TX;
          return 0;
        }
      ptls_ctx->write_buffer_offset += to_tls_len;

      if (TLS_WRITE_IS_LEFT (ptls_ctx))
        {
          app_session->flags |= SESSION_F_CUSTOM_TX;
          return to_tls_len;
        }
      else
        {
          ptls_buffer_init (&ptls_ctx->write_buffer, "", 0);
          ptls_ctx->write_buffer_offset = 0;
        }

    }

  deq_max = svm_fifo_max_dequeue_cons (app_tx_fifo);
  if (!deq_max)
    return deq_max;

  deq_now = clib_min (deq_max, sp->max_burst_size);
  deq_now = clib_min (deq_now, svm_fifo_max_read_chunk (app_tx_fifo));

  enq_max = svm_fifo_max_enqueue_prod (tls_tx_fifo);
    /** There is no engough enqueue space for one record **/
  if (enq_max <= record_overhead)
    {
      app_session->flags |= SESSION_F_CUSTOM_TX;
      return 0;
    }

  enq_now = clib_min (enq_max, svm_fifo_max_write_chunk (tls_tx_fifo));

    /** Allowed to execute no-copy crypto operation **/
  if (enq_now > record_overhead)
    {
      is_nocopy = 1;
      from_app_len = clib_min (deq_now, enq_now);
      num_records =
        ceil ((f64) from_app_len / PTLS_MAX_PLAINTEXT_RECORD_SIZE);
      total_overhead = num_records * record_overhead;
      if (from_app_len + total_overhead > enq_now)
        from_app_len = enq_now - total_overhead;
    }
  else
    {
      from_app_len = clib_min (deq_now, enq_max);
      num_records =
        ceil ((f64) from_app_len / PTLS_MAX_PLAINTEXT_RECORD_SIZE);
      total_overhead = num_records * record_overhead;
      if (from_app_len + total_overhead > enq_max)
        from_app_len = enq_max - total_overhead;
    }

  to_tls_len =
    picotls_content_process (ptls_ctx, app_tx_fifo, tls_tx_fifo,
                             from_app_len, total_overhead, is_nocopy);
  if (!TLS_WRITE_IS_LEFT (ptls_ctx))
    {
      ptls_ctx->write_buffer_offset = 0;
      ptls_buffer_init (&ptls_ctx->write_buffer, "", 0);
    }

  if (svm_fifo_needs_deq_ntf (app_tx_fifo, from_app_len))
    session_dequeue_notify (app_session);

  if (to_tls_len)
    tls_add_vpp_q_tx_evt (tls_session);

  if (from_app_len < deq_max || TLS_WRITE_IS_LEFT (ptls_ctx))
    app_session->flags |= SESSION_F_CUSTOM_TX;

  if (ctx->app_closed)
    picotls_app_close (ctx);

  return to_tls_len;
}

static int
picotls_ctx_init_server (tls_ctx_t * ctx)
{
  picotls_ctx_t *ptls_ctx = (picotls_ctx_t *) ctx;
  u32 ptls_lctx_idx = ctx->tls_ssl_ctx;
  picotls_listen_ctx_t *ptls_lctx;

  ptls_lctx = picotls_lctx_get (ptls_lctx_idx);
  ptls_ctx->tls = ptls_new (ptls_lctx->ptls_ctx, 1);
  if (ptls_ctx->tls == NULL)
    {
      TLS_DBG (1, "Failed to initialize ptls_ssl structure");
      return -1;
    }

  ptls_ctx->rx_len = 0;
  ptls_ctx->rx_offset = 0;

  ptls_ctx->write_buffer_offset = 0;
  return 0;
}

tls_ctx_t *
picotls_ctx_get_w_thread (u32 ctx_index, u8 thread_index)
{
  picotls_ctx_t **ctx;
  ctx = pool_elt_at_index (picotls_main.ctx_pool[thread_index], ctx_index);
  return &(*ctx)->ctx;
}

const static tls_engine_vft_t picotls_engine = {
  .ctx_alloc = picotls_ctx_alloc,
  .ctx_free = picotls_ctx_free,
  .ctx_get = picotls_ctx_get,
  .ctx_get_w_thread = picotls_ctx_get_w_thread,
  .ctx_handshake_is_over = picotls_handshake_is_over,
  .ctx_start_listen = picotls_start_listen,
  .ctx_stop_listen = picotls_stop_listen,
  .ctx_init_server = picotls_ctx_init_server,
  .ctx_read = picotls_ctx_read,
  .ctx_write = picotls_ctx_write,
  .ctx_transport_close = picotls_transport_close,
  .ctx_app_close = picotls_app_close,
};

static clib_error_t *
tls_picotls_init (vlib_main_t * vm)
{
  vlib_thread_main_t *vtm = vlib_get_thread_main ();
  picotls_main_t *pm = &picotls_main;
  clib_error_t *error = 0;
  u32 num_threads;

  num_threads = 1 + vtm->n_threads;

  vec_validate (pm->ctx_pool, num_threads - 1);

  tls_register_engine (&picotls_engine, CRYPTO_ENGINE_PICOTLS);

  return error;
}

/* *INDENT-OFF* */
VLIB_INIT_FUNCTION (tls_picotls_init) = {
  .runs_after = VLIB_INITS ("tls_init"),
};
/* *INDENT-ON* */

/* *INDENT-OFF* */
VLIB_PLUGIN_REGISTER () = {
  .version = VPP_BUILD_VER,
  .description = "Transport Layer Security (TLS) Engine, Picotls Based",
};
/* *INDENT-ON* */

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */