You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

137 lines
3.6 KiB

#include <ccan/endian/endian.h>
/* FIXME: io_plan needs size_t */
#include <unistd.h>
#include <ccan/io/io_plan.h>
#include <ccan/mem/mem.h>
#include <ccan/short_types/short_types.h>
#include <ccan/take/take.h>
#include <ccan/tal/tal.h>
#include <wire/wire_io.h>
/*
* OK, this is a little tricky. ccan/io lets you create your own plans,
* beyond the standard io_read/io_write etc. It provides a union to place
* scratch data, and it's almost enough for our purposes.
*/
/* 2 bytes for the length header. */
#define HEADER_LEN (sizeof(le16))
/* Since length can only be 64k, this is an impossible value. */
#define INSIDE_HEADER_BIT 0x80000000
/* arg->u2.s contains length we've read, arg->u1.vp contains u8 **data. */
static int do_read_wire_header(int fd, struct io_plan_arg *arg)
{
ssize_t ret;
size_t len = arg->u2.s & ~INSIDE_HEADER_BIT;
u8 *p = *(u8 **)arg->u1.vp;
ret = read(fd, p + len, HEADER_LEN - len);
if (ret <= 0)
return -1;
arg->u2.s += ret;
/* Both bytes read? Set up for normal read of data. */
if (arg->u2.s == INSIDE_HEADER_BIT + HEADER_LEN) {
arg->u2.s = be16_to_cpu(*(be16 *)p);
/* A type-only message is not unheard of, so optimize a little */
if (arg->u2.s != HEADER_LEN)
tal_resize((u8 **)arg->u1.vp, arg->u2.s);
arg->u1.vp = *(u8 **)arg->u1.vp;
}
return arg->u2.s == 0;
}
static int do_read_wire(int fd, struct io_plan_arg *arg)
{
ssize_t ret;
/* Still reading header? */
if (arg->u2.s & INSIDE_HEADER_BIT)
return do_read_wire_header(fd, arg);
/* Normal read */
ret = read(fd, arg->u1.cp, arg->u2.s);
if (ret <= 0)
return -1;
arg->u1.cp += ret;
arg->u2.s -= ret;
return arg->u2.s == 0;
}
struct io_plan *io_read_wire_(struct io_conn *conn,
const tal_t *ctx,
u8 **data,
struct io_plan *(*next)(struct io_conn *, void *),
void *next_arg)
{
struct io_plan_arg *arg = io_plan_arg(conn, IO_IN);
/* We allocate data now; saves storing ctx, and lets us read in len. */
arg->u1.vp = data;
*data = tal_arr(ctx, u8, HEADER_LEN);
/* We use u2 to store the length we've read. */
arg->u2.s = INSIDE_HEADER_BIT;
return io_set_plan(conn, IO_IN, do_read_wire, next, next_arg);
}
/* arg->u2.s contains length we've written, arg->u1 contains u8 *data. */
static int do_write_wire_header(int fd, struct io_plan_arg *arg)
{
ssize_t ret;
size_t len = arg->u2.s & ~INSIDE_HEADER_BIT;
be16 hdr = cpu_to_be16(tal_count(arg->u1.const_vp));
ret = write(fd, (char *)&hdr + len, HEADER_LEN - len);
if (ret <= 0)
return -1;
arg->u2.s += ret;
/* Both bytes written? Set up for normal write of data. */
if (arg->u2.s == INSIDE_HEADER_BIT + HEADER_LEN)
arg->u2.s = 0;
return 0;
}
static int do_write_wire(int fd, struct io_plan_arg *arg)
{
ssize_t ret;
size_t totlen = tal_len(arg->u1.cp);
/* Still writing header? */
if (arg->u2.s & INSIDE_HEADER_BIT)
return do_write_wire_header(fd, arg);
/* Normal write */
ret = write(fd, arg->u1.cp + arg->u2.s, totlen - arg->u2.s);
if (ret < 0)
return -1;
arg->u2.s += ret;
if (arg->u2.s != totlen)
return 0;
tal_free(arg->u1.cp);
return 1;
}
/* Write message from data (tal_count(data) gives length). */
struct io_plan *io_write_wire_(struct io_conn *conn,
const u8 *data,
struct io_plan *(*next)(struct io_conn *, void *),
void *next_arg)
{
struct io_plan_arg *arg = io_plan_arg(conn, IO_OUT);
arg->u1.const_vp = tal_dup_arr(conn, u8, memcheck(data, tal_len(data)),
tal_len(data), 0);
/* We use u2 to store the length we've written. */
arg->u2.s = INSIDE_HEADER_BIT;
return io_set_plan(conn, IO_OUT, do_write_wire, next, next_arg);
}