core-lightning/status.c
Rusty Russell 4b9eb19c68 status: don't send overlarge messages.
We'll assert if we try: better to truncate, trace a warning, and let the
recipient complain about a truncated message,

This is particularly an issue when we're sending encapsulated messages;
this avoids extra checks in the caller.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2017-01-10 15:25:20 +10:30

104 lines
2.1 KiB
C

#include "status.h"
#include "utils.h"
#include "wire/wire.h"
#include "wire/wire_sync.h"
#include <assert.h>
#include <ccan/breakpoint/breakpoint.h>
#include <ccan/endian/endian.h>
#include <ccan/err/err.h>
#include <ccan/fdpass/fdpass.h>
#include <ccan/read_write_all/read_write_all.h>
#include <ccan/tal/str/str.h>
#include <stdarg.h>
static int status_fd = -1;
const void *trc;
void status_setup(int fd)
{
status_fd = fd;
trc = tal_tmpctx(NULL);
}
static bool too_large(size_t len, int type)
{
if (len > 65535) {
status_trace("About to truncate msg %i from %zu bytes",
type, len);
return true;
}
return false;
}
void status_send(const u8 *p)
{
const u8 *msg = p;
assert(status_fd >= 0);
if (too_large(tal_count(p), fromwire_peektype(p)))
msg = tal_dup_arr(p, u8, p, 65535, 0);
if (!wire_sync_write(status_fd, msg))
err(1, "Writing out status len %zu", tal_count(msg));
tal_free(p);
}
void status_send_fd(int fd)
{
assert(status_fd >= 0);
assert(fd >= 0);
if (!fdpass_send(status_fd, fd))
err(1, "Writing out status fd %i", fd);
close(fd);
}
static void status_send_with_hdr(u16 type, const void *p, size_t len)
{
be16 be_type, be_len;
if (too_large(len + sizeof(be_type), type))
len = 65535 - sizeof(be_type);
be_type = cpu_to_be16(type);
be_len = cpu_to_be16(len + sizeof(be_type));
assert(status_fd >= 0);
assert(be16_to_cpu(be_len) == len + sizeof(be_type));
if (!write_all(status_fd, &be_len, sizeof(be_len))
|| !write_all(status_fd, &be_type, sizeof(be_type))
|| !write_all(status_fd, p, len))
err(1, "Writing out status %u len %zu", type, len);
}
void status_trace(const char *fmt, ...)
{
va_list ap;
char *str;
va_start(ap, fmt);
str = tal_vfmt(NULL, fmt, ap);
status_send_with_hdr(STATUS_TRACE, str, strlen(str));
tal_free(str);
va_end(ap);
/* Free up any temporary children. */
tal_free(trc);
trc = tal_tmpctx(NULL);
}
void status_failed(u16 code, const char *fmt, ...)
{
va_list ap;
char *str;
breakpoint();
assert(code & STATUS_FAIL);
va_start(ap, fmt);
str = tal_vfmt(NULL, fmt, ap);
status_send_with_hdr(code, str, strlen(str));
va_end(ap);
exit(0x80 | (code & 0xFF));
}