+extern void send_nak(const struct comm_addr *dest, uint32_t our_index,
+ uint32_t their_index, uint32_t msgtype,
+ struct buffer_if *buf, const char *logwhy);
+
+extern int consttime_memeq(const void *s1, const void *s2, size_t n);
+
+const char *iaddr_to_string(const union iaddr *ia);
+int iaddr_socklen(const union iaddr *ia);
+
+void string_item_to_iaddr(const item_t *item, uint16_t port, union iaddr *ia,
+ const char *desc);
+
+
+/*
+ * SBUF_DEFINE(int nbufs, size_t size);
+ * // Generates a number of definitions and statements organising
+ * // nbufs rotating char[size] buffers such that subsequent code
+ * // may refer to:
+ * char *const SBUF;
+ */
+#define SBUF_DEFINE(nbufs, size) \
+ static int static_bufs__bufnum; \
+ static char static_bufs__bufs[(nbufs)][(size)]; \
+ static_bufs__bufnum++; \
+ static_bufs__bufnum %= (nbufs); \
+ static_bufs__bufs[static_bufs__bufnum]
+#define SBUF (static_bufs__bufs[static_bufs__bufnum])
+
+/*----- line-buffered asynch input -----*/
+
+enum async_linebuf_result {
+ async_linebuf_nothing,
+ async_linebuf_ok,
+ async_linebuf_eof,
+ async_linebuf_broken,
+};
+
+const char *pollbadbit(int revents); /* returns 0, or bad bit description */
+
+enum async_linebuf_result
+async_linebuf_read(struct pollfd *pfd, struct buffer_if *buf,
+ const char **emsg_out);
+ /* Implements reading whole lines, asynchronously. Use like
+ * this:
+ * - set up the fd, which should be readable, O_NONBLOCK
+ * - set up and initialise buffer, which should be big enough
+ * for one line plus its trailing newline, and be empty
+ * with start==base
+ * - in your beforepoll_fn, be interested in POLLIN
+ * - in your afterpoll_fn, repeatedly call this function
+ * until it doesn't return `nothing'
+ * - after you're done, simply close fd and free or reset buf
+ * State on return from async_linebuf_read depends on return value:
+ *
+ * async_linebuf_nothing:
+ *
+ * No complete lines available right now. You should return
+ * from afterpoll. buf should be left untouched until the
+ * next call to async_linebuf_read.
+ *
+ * async_linebuf_ok:
+ *
+ * buf->base contains a input line as a nul-terminated string
+ * (\n replaced by \0); *emsg_out==0. You must call
+ * async_linebuf_read again before returning from afterpoll.
+ *
+ * async_linebuf_eof:
+ *
+ * EOF on stream. buf->base contains any partial
+ * (non-newline-terminated) line; *emsg_out!=0 iff there was
+ * such a partial line. You can call async_linebuf_read again
+ * if you like but it will probably just return eof again.
+ *
+ * broken:
+ *
+ * Fatal problem (might be overly long lines, nuls in input
+ * data, bad bits in pfd->revents, errors from read, etc.)
+ *
+ * *emsg_out is the error message describing the problem;
+ * this message might be stored in buf, might be from
+ * strerror, or might be a constant.
+ *
+ * You must not call async_linebuf_read again. buf contents
+ * is undefined: it is only safe to reset or free.
+ *
+ * While using this function, do not look at buf->start or ->size
+ * or anything after the first '\0' in buf.
+ *
+ * If you decide to stop reading with async_linebuf_read that's
+ * fine and you can reset or free buf, but you risk missing some
+ * read-but-not-reported data.
+ */
+
+/*----- some handy macros -----*/
+
+#define MINMAX(ae,be,op) ({ \
+ typeof((ae)) a=(ae); \
+ typeof((be)) b=(be); \
+ a op b ? a : b; \
+ })
+#define MAX(a,b) MINMAX((a),(b),>)
+#define MIN(a,b) MINMAX((a),(b),<)
+
+#define MAX_RAW(a,b) ((a)>(b)?(a):(b))
+#define MIN_RAW(a,b) ((a)<(b)?(a):(b))
+
+static inline bool_t iswouldblock(int e)
+ { return e==EWOULDBLOCK || e==EAGAIN; }
+