X-Git-Url: https://git.distorted.org.uk/~mdw/secnet/blobdiff_plain/2ec49059fbb09a119ede30da946b46e98c58199c..86420bb75f19f628ffd2d8ff9964e59ed99e3187:/util.h diff --git a/util.h b/util.h index 5866e57..4e1f9d0 100644 --- a/util.h +++ b/util.h @@ -1,3 +1,22 @@ +/* + * This file is part of secnet. + * See README for full list of copyright holders. + * + * secnet is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version d of the License, or + * (at your option) any later version. + * + * secnet is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * version 3 along with secnet; if not, see + * https://www.gnu.org/licenses/gpl.html. + */ + #ifndef util_h #define util_h @@ -23,12 +42,38 @@ extern void buffer_assert_used(struct buffer_if *buffer, cstring_t file, int line); extern void buffer_new(struct buffer_if *buffer, int32_t len); extern void buffer_init(struct buffer_if *buffer, int32_t max_start_pad); +extern void buffer_destroy(struct buffer_if *buffer); extern void buffer_copy(struct buffer_if *dst, const struct buffer_if *src); extern void *buf_append(struct buffer_if *buf, int32_t amount); extern void *buf_prepend(struct buffer_if *buf, int32_t amount); extern void *buf_unappend(struct buffer_if *buf, int32_t amount); extern void *buf_unprepend(struct buffer_if *buf, int32_t amount); +/* + * void BUF_ADD_BYTES(append, struct buffer_if*, const void*, int32_t size); + * void BUF_ADD_BYTES(prepend, struct buffer_if*, const void*, int32_t size); + * void BUF_GET_BYTES(unappend, struct buffer_if*, void*, int32_t size); + * void BUF_GET_BYTES(unprepend, struct buffer_if*, void*, int32_t size); + * // all of these evaluate size twice + * + * void BUF_ADD_OBJ(append, struct_buffer_if*, const OBJECT& something); + * void BUF_ADD_OBJ(prepend, struct_buffer_if*, const OBJECT& something); + * void BUF_GET_OBJ(unappend, struct_buffer_if*, OBJECT& something); + * void BUF_GET_OBJ(unprepend, struct_buffer_if*, OBJECT& something); + */ +#define BUF_ADD_BYTES(appendprepend, bufp, datap, size) \ + (buf_un##appendprepend /* ensures we have correct direction */, \ + memcpy(buf_##appendprepend((bufp),(size)),(datap),(size))) +#define BUF_ADD_OBJ(appendprepend, bufp, obj) \ + BUF_ADD_BYTES(appendprepend,(bufp),&(obj),sizeof((obj))) +#define BUF_GET_BYTES(unappendunprepend, bufp, datap, size) \ + (BUF_GET__DOESNOTEXIST__buf_un##unappendunprepend, \ + memcpy((datap),buf_##unappendunprepend((bufp),(size)),(size))) +#define BUF_GET_OBJ(unappendunprepend, bufp, obj) \ + BUF_ADD_BYTES(unappendunprepend,&(obj),(bufp),sizeof((obj))) +#define BUF_GET__DOESNOTEXIST__buf_ununappend 0 +#define BUF_GET__DOESNOTEXIST__buf_ununprepend 0 + static inline int32_t buf_remaining_space(const struct buffer_if *buf) { return (buf->base + buf->alloclen) - (buf->start + buf->size); @@ -56,6 +101,95 @@ extern void send_nak(const struct comm_addr *dest, uint32_t our_index, 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); \ @@ -64,4 +198,10 @@ extern int consttime_memeq(const void *s1, const void *s2, size_t n); #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; } + #endif /* util_h */