#include "git-compat-util.h"

#include "copy.h"

#include "pkt-line.h"

#include "gettext.h"

#include "hex.h"

#include "run-command.h"

#include "sideband.h"

#include "trace.h"

#include "write-or-die.h"

char packet_buffer[LARGE_PACKET_MAX];

static const char *packet_trace_prefix = "git";

static struct trace_key trace_packet = TRACE_KEY_INIT(PACKET);

static struct trace_key trace_pack = TRACE_KEY_INIT(PACKFILE);

void packet_trace_identity(const char *prog)

{

  packet_trace_prefix = xstrdup(prog);

}

static const char *get_trace_prefix(void)

{

  return in_async() ? "sideband" : packet_trace_prefix;

}

static int packet_trace_pack(const char *buf, unsigned int len, int sideband)

{

  if (!sideband) {

    trace_verbatim(&trace_pack, buf, len);

    return 1;

  } else if (len && *buf == '\1') {

    trace_verbatim(&trace_pack, buf + 1, len - 1);

    return 1;

  } else {

    /* it's another non-pack sideband */

    return 0;

  }

}

static void packet_trace(const char *buf, unsigned int len, int write)

{

  struct strbuf out;

  static int in_pack, sideband;

  if (!trace_want(&trace_packet) && !trace_want(&trace_pack))

    return;

  if (in_pack) {

    if (packet_trace_pack(buf, len, sideband))

      return;

  } else if (starts_with(buf, "PACK") || starts_with(buf, "\1PACK")) {

    in_pack = 1;

    sideband = *buf == '\1';

    packet_trace_pack(buf, len, sideband);

    /*

     * Make a note in the human-readable trace that the pack data

     * started.

     */

    buf = "PACK ...";

    len = strlen(buf);

  }

  if (!trace_want(&trace_packet))

    return;

  /* +32 is just a guess for header + quoting */

  strbuf_init(&out, len+32);

  strbuf_addf(&out, "packet: %12s%c ",

        get_trace_prefix(), write ? '>' : '<');

  /* XXX we should really handle printable utf8 */

  for (unsigned int i = 0; i < len; i++) {

    /* suppress newlines */

    if (buf[i] == '\n')

      continue;

    if (buf[i] >= 0x20 && buf[i] <= 0x7e)

      strbuf_addch(&out, buf[i]);

    else

      strbuf_addf(&out, "\\%o", buf[i]);

  }

  strbuf_addch(&out, '\n');

  trace_strbuf(&trace_packet, &out);

  strbuf_release(&out);

}

/*

 * If we buffered things up above (we don't, but we should),

 * we'd flush it here

 */

void packet_flush(int fd)

{

  packet_trace("0000", 4, 1);

  if (write_in_full(fd, "0000", 4) < 0)

    die_errno(_("unable to write flush packet"));

}

void packet_delim(int fd)

{

  packet_trace("0001", 4, 1);

  if (write_in_full(fd, "0001", 4) < 0)

    die_errno(_("unable to write delim packet"));

}

void packet_response_end(int fd)

{

  packet_trace("0002", 4, 1);

  if (write_in_full(fd, "0002", 4) < 0)

    die_errno(_("unable to write response end packet"));

}

int packet_flush_gently(int fd)

{

  packet_trace("0000", 4, 1);

  if (write_in_full(fd, "0000", 4) < 0)

    return error(_("flush packet write failed"));

  return 0;

}

void packet_buf_flush(struct strbuf *buf)

{

  packet_trace("0000", 4, 1);

  strbuf_add(buf, "0000", 4);

}

void packet_buf_delim(struct strbuf *buf)

{

  packet_trace("0001", 4, 1);

  strbuf_add(buf, "0001", 4);

}

void set_packet_header(char *buf, int size)

{

  static char hexchar[] = "0123456789abcdef";

  #define hex(a) (hexchar[(a) & 15])

  buf[0] = hex(size >> 12);

  buf[1] = hex(size >> 8);

  buf[2] = hex(size >> 4);

  buf[3] = hex(size);

  #undef hex

}

static void format_packet(struct strbuf *out, const char *prefix,

        const char *fmt, va_list args)

{

  size_t orig_len, n;

  orig_len = out->len;

  strbuf_addstr(out, "0000");

  strbuf_addstr(out, prefix);

  strbuf_vaddf(out, fmt, args);

  n = out->len - orig_len;

  if (n > LARGE_PACKET_MAX)

    die(_("protocol error: impossibly long line"));

  set_packet_header(&out->buf[orig_len], n);

  packet_trace(out->buf + orig_len + 4, n - 4, 1);

}

static int packet_write_fmt_1(int fd, int gently, const char *prefix,

            const char *fmt, va_list args)

{

  static struct strbuf buf = STRBUF_INIT;

  strbuf_reset(&buf);

  format_packet(&buf, prefix, fmt, args);

  if (write_in_full(fd, buf.buf, buf.len) < 0) {

    if (!gently) {

      check_pipe(errno);

      die_errno(_("packet write with format failed"));

    }

    return error(_("packet write with format failed"));

  }

  return 0;

}

void packet_write_fmt(int fd, const char *fmt, ...)

{

  va_list args;

  va_start(args, fmt);

  packet_write_fmt_1(fd, 0, "", fmt, args);

  va_end(args);

}

int packet_write_fmt_gently(int fd, const char *fmt, ...)

{

  int status;

  va_list args;

  va_start(args, fmt);

  status = packet_write_fmt_1(fd, 1, "", fmt, args);

  va_end(args);

  return status;

}

static int do_packet_write(const int fd_out, const char *buf, size_t size,

         struct strbuf *err)

{

  char header[4];

  size_t packet_size;

  if (size > LARGE_PACKET_DATA_MAX) {

    strbuf_addstr(err, _("packet write failed - data exceeds max packet size"));

    return -1;

  }

  packet_trace(buf, size, 1);

  packet_size = size + 4;

  set_packet_header(header, packet_size);

  /*

   * Write the header and the buffer in 2 parts so that we do

   * not need to allocate a buffer or rely on a static buffer.

   * This also avoids putting a large buffer on the stack which

   * might have multi-threading issues.

   */

  if (write_in_full(fd_out, header, 4) < 0 ||

      write_in_full(fd_out, buf, size) < 0) {

    strbuf_addf(err, _("packet write failed: %s"), strerror(errno));

    return -1;

  }

  return 0;

}

static int packet_write_gently(const int fd_out, const char *buf, size_t size)

{

  struct strbuf err = STRBUF_INIT;

  if (do_packet_write(fd_out, buf, size, &err)) {

    error("%s", err.buf);

    strbuf_release(&err);

    return -1;

  }

  return 0;

}

void packet_write(int fd_out, const char *buf, size_t size)

{

  struct strbuf err = STRBUF_INIT;

  if (do_packet_write(fd_out, buf, size, &err))

    die("%s", err.buf);

}

void packet_fwrite(FILE *f, const char *buf, size_t size)

{

  size_t packet_size;

  char header[4];

  if (size > LARGE_PACKET_DATA_MAX)

    die(_("packet write failed - data exceeds max packet size"));

  packet_trace(buf, size, 1);

  packet_size = size + 4;

  set_packet_header(header, packet_size);

  fwrite_or_die(f, header, 4);

  fwrite_or_die(f, buf, size);

}

void packet_fwrite_fmt(FILE *fh, const char *fmt, ...)

{

       static struct strbuf buf = STRBUF_INIT;

       va_list args;

       strbuf_reset(&buf);

       va_start(args, fmt);

       format_packet(&buf, "", fmt, args);

       va_end(args);

       fwrite_or_die(fh, buf.buf, buf.len);

}

void packet_fflush(FILE *f)

{

  packet_trace("0000", 4, 1);

  fwrite_or_die(f, "0000", 4);

  fflush_or_die(f);

}

void packet_buf_write(struct strbuf *buf, const char *fmt, ...)

{

  va_list args;

  va_start(args, fmt);

  format_packet(buf, "", fmt, args);

  va_end(args);

}

int write_packetized_from_fd_no_flush(int fd_in, int fd_out)

{

  char *buf = xmalloc(LARGE_PACKET_DATA_MAX);

  int err = 0;

  ssize_t bytes_to_write;

  while (!err) {

    bytes_to_write = xread(fd_in, buf, LARGE_PACKET_DATA_MAX);

    if (bytes_to_write < 0) {

      free(buf);

      return COPY_READ_ERROR;

    }

    if (bytes_to_write == 0)

      break;

    err = packet_write_gently(fd_out, buf, bytes_to_write);

  }

  free(buf);

  return err;

}

int write_packetized_from_buf_no_flush_count(const char *src_in, size_t len,

               int fd_out, int *packet_counter)

{

  int err = 0;

  size_t bytes_written = 0;

  size_t bytes_to_write;

  while (!err) {

    if ((len - bytes_written) > LARGE_PACKET_DATA_MAX)

      bytes_to_write = LARGE_PACKET_DATA_MAX;

    else

      bytes_to_write = len - bytes_written;

    if (bytes_to_write == 0)

      break;

    err = packet_write_gently(fd_out, src_in + bytes_written, bytes_to_write);

    bytes_written += bytes_to_write;

    if (packet_counter)

      (*packet_counter)++;

  }

  return err;

}

static int get_packet_data(int fd, char **src_buf, size_t *src_size,

         void *dst, size_t size, int options)

{

  size_t bytes_read;

  if (fd >= 0 && src_buf && *src_buf)

    BUG("multiple sources given to packet_read");

  /* Read up to "size" bytes from our source, whatever it is. */

  if (src_buf && *src_buf) {

    bytes_read = size < *src_size ? size : *src_size;

    memcpy(dst, *src_buf, bytes_read);

    *src_buf += bytes_read;

    *src_size -= bytes_read;

  } else {

    ssize_t ret = read_in_full(fd, dst, size);

    if (ret < 0) {

      if (options & PACKET_READ_GENTLE_ON_READ_ERROR)

        return error_errno(_("read error"));

      die_errno(_("read error"));

    }

    bytes_read = (size_t) ret;

  }

  /* And complain if we didn't get enough bytes to satisfy the read. */

  if (bytes_read != size) {

    if (options & PACKET_READ_GENTLE_ON_EOF)

      return -1;

    if (options & PACKET_READ_GENTLE_ON_READ_ERROR)

      return error(_("the remote end hung up unexpectedly"));

    die(_("the remote end hung up unexpectedly"));

  }

  return 0;

}

int packet_length(const char lenbuf_hex[4], size_t size)

{

  if (size < 4)

    BUG("buffer too small");

  return  hexval(lenbuf_hex[0]) << 12 |

    hexval(lenbuf_hex[1]) <<  8 |

    hexval(lenbuf_hex[2]) <<  4 |

    hexval(lenbuf_hex[3]);

}

static char *find_packfile_uri_path(const char *buffer)

{

  const char *URI_MARK = "://";

  char *path;

  int len;

  /* First char is sideband mark */

  buffer += 1;

  len = strspn(buffer, "0123456789abcdefABCDEF");

  /* size of SHA1 and SHA256 hash */

  if (!(len == 40 || len == 64) || buffer[len] != ' ')

    return NULL; /* required "<hash>SP" not seen */

  path = strstr(buffer + len + 1, URI_MARK);

  if (!path)

    return NULL;

  path = strchr(path + strlen(URI_MARK), '/');

  if (!path || !*(path + 1))

    return NULL;

  /* position after '/' */

  return ++path;

}

enum packet_read_status packet_read_with_status(int fd, char **src_buffer,

            size_t *src_len, char *buffer,

            unsigned size, int *pktlen,

            int options)

{

  int len;

  char linelen[4];

  char *uri_path_start;

  if (get_packet_data(fd, src_buffer, src_len, linelen, 4, options) < 0) {

    *pktlen = -1;

    return PACKET_READ_EOF;

  }

  len = packet_length(linelen, sizeof(linelen));

  if (len < 0) {

    if (options & PACKET_READ_GENTLE_ON_READ_ERROR)

      return error(_("protocol error: bad line length "

               "character: %.4s"), linelen);

    die(_("protocol error: bad line length character: %.4s"), linelen);

  } else if (!len) {

    packet_trace("0000", 4, 0);

    *pktlen = 0;

    return PACKET_READ_FLUSH;

  } else if (len == 1) {

    packet_trace("0001", 4, 0);

    *pktlen = 0;

    return PACKET_READ_DELIM;

  } else if (len == 2) {

    packet_trace("0002", 4, 0);

    *pktlen = 0;

    return PACKET_READ_RESPONSE_END;

  } else if (len < 4) {

    if (options & PACKET_READ_GENTLE_ON_READ_ERROR)

      return error(_("protocol error: bad line length %d"),

             len);

    die(_("protocol error: bad line length %d"), len);

  }

  len -= 4;

  if ((unsigned)len >= size) {

    if (options & PACKET_READ_GENTLE_ON_READ_ERROR)

      return error(_("protocol error: bad line length %d"),

             len);

    die(_("protocol error: bad line length %d"), len);

  }

  if (get_packet_data(fd, src_buffer, src_len, buffer, len, options) < 0) {

    *pktlen = -1;

    return PACKET_READ_EOF;

  }

  if ((options & PACKET_READ_CHOMP_NEWLINE) &&

      len && buffer[len-1] == '\n') {

    if (options & PACKET_READ_USE_SIDEBAND) {

      int band = *buffer & 0xff;

      switch (band) {

      case 1:

        /* Chomp newline for payload */

        len--;

        break;

      case 2:

      case 3:

        /*

         * Do not chomp newline for progress and error

         * message.

         */

        break;

      default:

        /*

         * Bad sideband, let's leave it to

         * demultiplex_sideband() to catch this error.

         */

        break;

      }

    } else {

      len--;

    }

  }

  buffer[len] = 0;

  if (options & PACKET_READ_REDACT_URI_PATH &&

      (uri_path_start = find_packfile_uri_path(buffer))) {

    const char *redacted = "<redacted>";

    struct strbuf tracebuf = STRBUF_INIT;

    strbuf_insert(&tracebuf, 0, buffer, len);

    strbuf_splice(&tracebuf, uri_path_start - buffer,

            strlen(uri_path_start), redacted, strlen(redacted));

    packet_trace(tracebuf.buf, tracebuf.len, 0);

    strbuf_release(&tracebuf);

  } else {

    packet_trace(buffer, len, 0);

  }

  if ((options & PACKET_READ_DIE_ON_ERR_PACKET) &&

      starts_with(buffer, "ERR "))

    die(_("remote error: %s"), buffer + 4);

  *pktlen = len;

  return PACKET_READ_NORMAL;

}

int packet_read(int fd, char *buffer, unsigned size, int options)

{

  int pktlen = -1;

  packet_read_with_status(fd, NULL, NULL, buffer, size, &pktlen,

        options);

  return pktlen;

}

char *packet_read_line(int fd, int *dst_len)

{

  int len = packet_read(fd, packet_buffer, sizeof(packet_buffer),

            PACKET_READ_CHOMP_NEWLINE);

  if (dst_len)

    *dst_len = len;

  return (len > 0) ? packet_buffer : NULL;

}

int packet_read_line_gently(int fd, int *dst_len, char **dst_line)

{

  int len = packet_read(fd, packet_buffer, sizeof(packet_buffer),

            PACKET_READ_CHOMP_NEWLINE|PACKET_READ_GENTLE_ON_EOF);

  if (dst_len)

    *dst_len = len;

  if (dst_line)

    *dst_line = (len > 0) ? packet_buffer : NULL;

  return len;

}

ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out, int options)

{

  int packet_len;

  size_t orig_len = sb_out->len;

  size_t orig_alloc = sb_out->alloc;

  for (;;) {

    strbuf_grow(sb_out, LARGE_PACKET_DATA_MAX);

    packet_len = packet_read(fd_in,

      /* strbuf_grow() above always allocates one extra byte to

       * store a '\0' at the end of the string. packet_read()

       * writes a '\0' extra byte at the end, too. Let it know

       * that there is already room for the extra byte.

       */

      sb_out->buf + sb_out->len, LARGE_PACKET_DATA_MAX+1,

      options);

    if (packet_len <= 0)

      break;

    sb_out->len += packet_len;

  }

  if (packet_len < 0) {

    if (orig_alloc == 0)

      strbuf_release(sb_out);

    else

      strbuf_setlen(sb_out, orig_len);

    return packet_len;

  }

  return sb_out->len - orig_len;

}

int recv_sideband(const char *me, int in_stream, int out)

{

  char buf[LARGE_PACKET_MAX + 1];

  int len;

  struct strbuf scratch = STRBUF_INIT;

  enum sideband_type sideband_type;

  while (1) {

    int status = packet_read_with_status(in_stream, NULL, NULL,

                 buf, LARGE_PACKET_MAX,

                 &len,

                 PACKET_READ_GENTLE_ON_EOF);

    if (!demultiplex_sideband(me, status, buf, len, 0, &scratch,

            &sideband_type))

      continue;

    switch (sideband_type) {

    case SIDEBAND_PRIMARY:

      write_or_die(out, buf + 1, len - 1);

      break;

    default: /* errors: message already written */

      if (scratch.len > 0)

        BUG("unhandled incomplete sideband: '%s'",

            scratch.buf);

      return sideband_type;

    }

  }

}

/* Packet Reader Functions */

void packet_reader_init(struct packet_reader *reader, int fd,

      char *src_buffer, size_t src_len,

      int options)

{

  memset(reader, 0, sizeof(*reader));

  reader->fd = fd;

  reader->src_buffer = src_buffer;

  reader->src_len = src_len;

  reader->buffer = packet_buffer;

  reader->buffer_size = sizeof(packet_buffer);

  reader->options = options;

  reader->me = "git";

  reader->hash_algo = &hash_algos[GIT_HASH_SHA1_LEGACY];

  strbuf_init(&reader->scratch, 0);

}

enum packet_read_status packet_reader_read(struct packet_reader *reader)

{

  if (reader->line_peeked) {

    reader->line_peeked = 0;

    return reader->status;

  }

  if (reader->use_sideband)

    reader->options |= PACKET_READ_USE_SIDEBAND;

  /*

   * Consume all progress packets until a primary payload packet is

   * received

   */

  while (1) {

    enum sideband_type sideband_type;

    reader->status = packet_read_with_status(reader->fd,

               &reader->src_buffer,

               &reader->src_len,

               reader->buffer,

               reader->buffer_size,

               &reader->pktlen,

               reader->options);

    if (!reader->use_sideband)

      break;

    if (demultiplex_sideband(reader->me, reader->status,

           reader->buffer, reader->pktlen, 1,

           &reader->scratch, &sideband_type))

      break;

  }

  if (reader->status == PACKET_READ_NORMAL)

    /* Skip the sideband designator if sideband is used */

    reader->line = reader->use_sideband ?

      reader->buffer + 1 : reader->buffer;

  else

    reader->line = NULL;

  return reader->status;

}

enum packet_read_status packet_reader_peek(struct packet_reader *reader)

{

  /* Only allow peeking a single line */

  if (reader->line_peeked)

    return reader->status;

  /* Peek a line by reading it and setting peeked flag */

  packet_reader_read(reader);

  reader->line_peeked = 1;

  return reader->status;

}

void packet_writer_init(struct packet_writer *writer, int dest_fd)

{

  writer->dest_fd = dest_fd;

  writer->use_sideband = 0;

}

void packet_writer_write(struct packet_writer *writer, const char *fmt, ...)

{

  va_list args;

  va_start(args, fmt);

  packet_write_fmt_1(writer->dest_fd, 0,

         writer->use_sideband ? "\001" : "", fmt, args);

  va_end(args);

}

void packet_writer_error(struct packet_writer *writer, const char *fmt, ...)

{

  va_list args;

  va_start(args, fmt);

  packet_write_fmt_1(writer->dest_fd, 0,

         writer->use_sideband ? "\003" : "ERR ", fmt, args);

  va_end(args);

}

void packet_writer_delim(struct packet_writer *writer)

{

  packet_delim(writer->dest_fd);

}

void packet_writer_flush(struct packet_writer *writer)

{

  packet_flush(writer->dest_fd);

}