iPXE
Functions
linebuf.c File Reference

Line buffering. More...

#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <ipxe/linebuf.h>

Go to the source code of this file.

Functions

 FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
char * buffered_line (struct line_buffer *linebuf)
 Retrieve buffered-up line.
void empty_line_buffer (struct line_buffer *linebuf)
 Discard line buffer contents.
int line_buffer (struct line_buffer *linebuf, const char *data, size_t len)
 Buffer up received data by lines.

Detailed Description

Line buffering.

Definition in file linebuf.c.


Function Documentation

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL  )
char* buffered_line ( struct line_buffer linebuf)

Retrieve buffered-up line.

Parameters:
linebufLine buffer
Return values:
lineBuffered line, or NULL if no line ready to read

Definition at line 45 of file linebuf.c.

References line_buffer::consumed, line_buffer::data, line_buffer::len, and NULL.

Referenced by http_rx_chunk_len(), http_rx_headers(), http_rx_trailers(), linebuf_consume_okx(), linebuf_empty_okx(), and linebuf_init_okx().

                                                     {
        char *line = &linebuf->data[ linebuf->len ];

        /* Fail unless we have a newly completed line to retrieve */
        if ( ( linebuf->len == 0 ) || ( linebuf->consumed == 0 ) ||
             ( *(--line) != '\0' ) )
                return NULL;

        /* Identify start of line */
        while ( ( line > linebuf->data ) && ( line[-1] != '\0' ) )
                line--;

        return line;
}
void empty_line_buffer ( struct line_buffer linebuf)

Discard line buffer contents.

Parameters:
linebufLine buffer

Definition at line 65 of file linebuf.c.

References line_buffer::consumed, line_buffer::data, free, line_buffer::len, and NULL.

Referenced by http_free(), http_rx_chunk_len(), http_rx_trailers(), http_tx_request(), and linebuf_empty_okx().

                                                       {

        free ( linebuf->data );
        linebuf->data = NULL;
        linebuf->len = 0;
        linebuf->consumed = 0;
}
int line_buffer ( struct line_buffer linebuf,
const char *  data,
size_t  len 
)

Buffer up received data by lines.

Parameters:
linebufLine buffer
dataNew data to add
lenLength of new data to add
Return values:
lenConsumed length, or negative error number

After calling line_buffer(), use buffered_line() to determine whether or not a complete line is available. Carriage returns and newlines will have been stripped, and the line will be NUL-terminated. This buffered line is valid only until the next call to line_buffer() (or to empty_line_buffer()).

Note that line buffers use dynamically allocated storage; you should call empty_line_buffer() before freeing a struct line_buffer.

Definition at line 91 of file linebuf.c.

References assert, line_buffer::consumed, cr, line_buffer::data, EINVAL, ENOMEM, line_buffer::len, len, memchr(), memcpy(), and realloc().

Referenced by http_rx_linebuf(), and linebuf_consume_okx().

                                                                              {
        const char *eol;
        size_t consume;
        size_t new_len;
        char *new_data;
        char *lf;
        char *cr;

        /* Search for line terminator */
        if ( ( eol = memchr ( data, '\n', len ) ) ) {
                consume = ( eol - data + 1 );
        } else {
                consume = len;
        }

        /* Reject any embedded NULs within the data to be consumed */
        if ( memchr ( data, '\0', consume ) )
                return -EINVAL;

        /* Reallocate data buffer and copy in new data */
        new_len = ( linebuf->len + consume );
        new_data = realloc ( linebuf->data, ( new_len + 1 ) );
        if ( ! new_data )
                return -ENOMEM;
        memcpy ( ( new_data + linebuf->len ), data, consume );
        new_data[new_len] = '\0';
        linebuf->data = new_data;
        linebuf->len = new_len;

        /* If we have reached end of line, terminate the line */
        if ( eol ) {

                /* Overwrite trailing LF (which must exist at this point) */
                assert ( linebuf->len > 0 );
                lf = &linebuf->data[ linebuf->len - 1 ];
                assert ( *lf == '\n' );
                *lf = '\0';

                /* Trim (and overwrite) trailing CR, if present */
                if ( linebuf->len > 1 ) {
                        cr = ( lf - 1 );
                        if ( *cr == '\r' ) {
                                linebuf->len--;
                                *cr = '\0';
                        }
                }
        }

        /* Record consumed length */
        linebuf->consumed = consume;

        return consume;
}