/* * Copyright (c) 2003, 2004 Niels Provos * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #ifdef HAVE_SYS_TYPES_H #include #endif #ifdef HAVE_SYS_PARAM_H #include #endif #ifdef WIN32 #define WIN32_LEAN_AND_MEAN #include #include #undef WIN32_LEAN_AND_MEAN #else #include #endif #include #ifdef HAVE_SYS_TIME_H #include #endif #include #include #include #include #ifndef WIN32 #include #endif #ifdef HAVE_UNISTD_H #include #endif #include "event.h" #include "evutil.h" #include "log.h" int evtag_decode_int(ev_uint32_t *pnumber, struct evbuffer *evbuf); int evtag_encode_tag(struct evbuffer *evbuf, ev_uint32_t tag); int evtag_decode_tag(ev_uint32_t *ptag, struct evbuffer *evbuf); static struct evbuffer *_buf; /* not thread safe */ void evtag_init(void) { if (_buf != NULL) return; if ((_buf = evbuffer_new()) == NULL) event_err(1, "%s: malloc", __func__); } /* * We encode integer's by nibbles; the first nibble contains the number * of significant nibbles - 1; this allows us to encode up to 64-bit * integers. This function is byte-order independent. */ void encode_int(struct evbuffer *evbuf, ev_uint32_t number) { int off = 1, nibbles = 0; ev_uint8_t data[5]; memset(data, 0, sizeof(ev_uint32_t)+1); while (number) { if (off & 0x1) data[off/2] = (data[off/2] & 0xf0) | (number & 0x0f); else data[off/2] = (data[off/2] & 0x0f) | ((number & 0x0f) << 4); number >>= 4; off++; } if (off > 2) nibbles = off - 2; /* Off - 1 is the number of encoded nibbles */ data[0] = (data[0] & 0x0f) | ((nibbles & 0x0f) << 4); evbuffer_add(evbuf, data, (off + 1) / 2); } /* * Support variable length encoding of tags; we use the high bit in each * octet as a continuation signal. */ int evtag_encode_tag(struct evbuffer *evbuf, ev_uint32_t tag) { int bytes = 0; ev_uint8_t data[5]; memset(data, 0, sizeof(data)); do { ev_uint8_t lower = tag & 0x7f; tag >>= 7; if (tag) lower |= 0x80; data[bytes++] = lower; } while (tag); if (evbuf != NULL) evbuffer_add(evbuf, data, bytes); return (bytes); } static int decode_tag_internal(ev_uint32_t *ptag, struct evbuffer *evbuf, int dodrain) { ev_uint32_t number = 0; ev_uint8_t *data = EVBUFFER_DATA(evbuf); int len = EVBUFFER_LENGTH(evbuf); int count = 0, shift = 0, done = 0; while (count++ < len) { ev_uint8_t lower = *data++; number |= (lower & 0x7f) << shift; shift += 7; if (!(lower & 0x80)) { done = 1; break; } } if (!done) return (-1); if (dodrain) evbuffer_drain(evbuf, count); if (ptag != NULL) *ptag = number; return (count); } int evtag_decode_tag(ev_uint32_t *ptag, struct evbuffer *evbuf) { return (decode_tag_internal(ptag, evbuf, 1 /* dodrain */)); } /* * Marshal a data type, the general format is as follows: * * tag number: one byte; length: var bytes; payload: var bytes */ void evtag_marshal(struct evbuffer *evbuf, ev_uint32_t tag, const void *data, ev_uint32_t len) { evtag_encode_tag(evbuf, tag); encode_int(evbuf, len); evbuffer_add(evbuf, (void *)data, len); } /* Marshaling for integers */ void evtag_marshal_int(struct evbuffer *evbuf, ev_uint32_t tag, ev_uint32_t integer) { evbuffer_drain(_buf, EVBUFFER_LENGTH(_buf)); encode_int(_buf, integer); evtag_encode_tag(evbuf, tag); encode_int(evbuf, EVBUFFER_LENGTH(_buf)); evbuffer_add_buffer(evbuf, _buf); } void evtag_marshal_string(struct evbuffer *buf, ev_uint32_t tag, const char *string) { evtag_marshal(buf, tag, string, strlen(string)); } void evtag_marshal_timeval(struct evbuffer *evbuf, ev_uint32_t tag, struct timeval *tv) { evbuffer_drain(_buf, EVBUFFER_LENGTH(_buf)); encode_int(_buf, tv->tv_sec); encode_int(_buf, tv->tv_usec); evtag_marshal(evbuf, tag, EVBUFFER_DATA(_buf), EVBUFFER_LENGTH(_buf)); } static int decode_int_internal(ev_uint32_t *pnumber, struct evbuffer *evbuf, int dodrain) { ev_uint32_t number = 0; ev_uint8_t *data = EVBUFFER_DATA(evbuf); int len = EVBUFFER_LENGTH(evbuf); int nibbles = 0; if (!len) return (-1); nibbles = ((data[0] & 0xf0) >> 4) + 1; if (nibbles > 8 || (nibbles >> 1) + 1 > len) return (-1); len = (nibbles >> 1) + 1; while (nibbles > 0) { number <<= 4; if (nibbles & 0x1) number |= data[nibbles >> 1] & 0x0f; else number |= (data[nibbles >> 1] & 0xf0) >> 4; nibbles--; } if (dodrain) evbuffer_drain(evbuf, len); *pnumber = number; return (len); } int evtag_decode_int(ev_uint32_t *pnumber, struct evbuffer *evbuf) { return (decode_int_internal(pnumber, evbuf, 1) == -1 ? -1 : 0); } int evtag_peek(struct evbuffer *evbuf, ev_uint32_t *ptag) { return (decode_tag_internal(ptag, evbuf, 0 /* dodrain */)); } int evtag_peek_length(struct evbuffer *evbuf, ev_uint32_t *plength) { struct evbuffer tmp; int res, len; len = decode_tag_internal(NULL, evbuf, 0 /* dodrain */); if (len == -1) return (-1); tmp = *evbuf; tmp.buffer += len; tmp.off -= len; res = decode_int_internal(plength, &tmp, 0); if (res == -1) return (-1); *plength += res + len; return (0); } int evtag_payload_length(struct evbuffer *evbuf, ev_uint32_t *plength) { struct evbuffer tmp; int res, len; len = decode_tag_internal(NULL, evbuf, 0 /* dodrain */); if (len == -1) return (-1); tmp = *evbuf; tmp.buffer += len; tmp.off -= len; res = decode_int_internal(plength, &tmp, 0); if (res == -1) return (-1); return (0); } int evtag_consume(struct evbuffer *evbuf) { ev_uint32_t len; if (decode_tag_internal(NULL, evbuf, 1 /* dodrain */) == -1) return (-1); if (evtag_decode_int(&len, evbuf) == -1) return (-1); evbuffer_drain(evbuf, len); return (0); } /* Reads the data type from an event buffer */ int evtag_unmarshal(struct evbuffer *src, ev_uint32_t *ptag, struct evbuffer *dst) { ev_uint32_t len; ev_uint32_t integer; if (decode_tag_internal(ptag, src, 1 /* dodrain */) == -1) return (-1); if (evtag_decode_int(&integer, src) == -1) return (-1); len = integer; if (EVBUFFER_LENGTH(src) < len) return (-1); if (evbuffer_add(dst, EVBUFFER_DATA(src), len) == -1) return (-1); evbuffer_drain(src, len); return (len); } /* Marshaling for integers */ int evtag_unmarshal_int(struct evbuffer *evbuf, ev_uint32_t need_tag, ev_uint32_t *pinteger) { ev_uint32_t tag; ev_uint32_t len; ev_uint32_t integer; if (decode_tag_internal(&tag, evbuf, 1 /* dodrain */) == -1) return (-1); if (need_tag != tag) return (-1); if (evtag_decode_int(&integer, evbuf) == -1) return (-1); len = integer; if (EVBUFFER_LENGTH(evbuf) < len) return (-1); evbuffer_drain(_buf, EVBUFFER_LENGTH(_buf)); if (evbuffer_add(_buf, EVBUFFER_DATA(evbuf), len) == -1) return (-1); evbuffer_drain(evbuf, len); return (evtag_decode_int(pinteger, _buf)); } /* Unmarshal a fixed length tag */ int evtag_unmarshal_fixed(struct evbuffer *src, ev_uint32_t need_tag, void *data, size_t len) { ev_uint32_t tag; /* Initialize this event buffer so that we can read into it */ evbuffer_drain(_buf, EVBUFFER_LENGTH(_buf)); /* Now unmarshal a tag and check that it matches the tag we want */ if (evtag_unmarshal(src, &tag, _buf) == -1 || tag != need_tag) return (-1); if (EVBUFFER_LENGTH(_buf) != len) return (-1); memcpy(data, EVBUFFER_DATA(_buf), len); return (0); } int evtag_unmarshal_string(struct evbuffer *evbuf, ev_uint32_t need_tag, char **pstring) { ev_uint32_t tag; evbuffer_drain(_buf, EVBUFFER_LENGTH(_buf)); if (evtag_unmarshal(evbuf, &tag, _buf) == -1 || tag != need_tag) return (-1); *pstring = calloc(EVBUFFER_LENGTH(_buf) + 1, 1); if (*pstring == NULL) event_err(1, "%s: calloc", __func__); evbuffer_remove(_buf, *pstring, EVBUFFER_LENGTH(_buf)); return (0); } int evtag_unmarshal_timeval(struct evbuffer *evbuf, ev_uint32_t need_tag, struct timeval *ptv) { ev_uint32_t tag; ev_uint32_t integer; evbuffer_drain(_buf, EVBUFFER_LENGTH(_buf)); if (evtag_unmarshal(evbuf, &tag, _buf) == -1 || tag != need_tag) return (-1); if (evtag_decode_int(&integer, _buf) == -1) return (-1); ptv->tv_sec = integer; if (evtag_decode_int(&integer, _buf) == -1) return (-1); ptv->tv_usec = integer; return (0); }