Edit
kc3-lang/libevent/event_tagging.c
Nick Mathewson
- event_tagging.c
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/* * Copyright (c) 2003-2009 Niels Provos <provos@citi.umich.edu> * Copyright (c) 2009-2010 Niels Provos and Nick Mathewson * * 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. */ #include "event-config.h" #ifdef _EVENT_HAVE_SYS_TYPES_H #include <sys/types.h> #endif #ifdef _EVENT_HAVE_SYS_PARAM_H #include <sys/param.h> #endif #ifdef WIN32 #define WIN32_LEAN_AND_MEAN #include <winsock2.h> #include <windows.h> #undef WIN32_LEAN_AND_MEAN #else #include <sys/ioctl.h> #endif #include <sys/queue.h> #ifdef _EVENT_HAVE_SYS_TIME_H #include <sys/time.h> #endif #include <errno.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #ifndef WIN32 #include <syslog.h> #endif #ifdef _EVENT_HAVE_UNISTD_H #include <unistd.h> #endif #include "event2/event.h" #include "event2/tag.h" #include "event2/buffer.h" #include "log-internal.h" #include "mm-internal.h" #include "util-internal.h" /* Here's our wire format: Stream = TaggedData* TaggedData = Tag Length Data where the integer value of 'Length' is the length of 'data'. Tag = HByte* LByte where HByte is a byte with the high bit set, and LByte is a byte with the high bit clear. The integer value of the tag is taken by concatenating the lower 7 bits from all the tags. So for example, the tag 0x66 is encoded as [66], whereas the tag 0x166 is encoded as [82 66] Length = Integer Integer = NNibbles Nibble* Padding? where NNibbles is a 4-bit value encoding the number of nibbles-1, and each Nibble is 4 bits worth of encoded integer, in big-endian order. If the total encoded integer size is an odd number of nibbles, a final padding nibble with value 0 is appended. */ int evtag_decode_int(ev_uint32_t *pnumber, struct evbuffer *evbuf); int evtag_decode_int64(ev_uint64_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); void evtag_init(void) { } /* * We encode integers 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. * * @param number a 32-bit unsigned integer to encode * @param data a pointer to where the data should be written. Must * have at least 5 bytes free. * @return the number of bytes written into data. */ #define ENCODE_INT_INTERNAL(data, number) do { \ int off = 1, nibbles = 0; \ \ memset(data, 0, sizeof(number)+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); \ \ return ((off + 1) / 2); \ } while (0) static inline int encode_int_internal(ev_uint8_t *data, ev_uint32_t number) { ENCODE_INT_INTERNAL(data, number); } static inline int encode_int64_internal(ev_uint8_t *data, ev_uint64_t number) { ENCODE_INT_INTERNAL(data, number); } void evtag_encode_int(struct evbuffer *evbuf, ev_uint32_t number) { ev_uint8_t data[5]; int len = encode_int_internal(data, number); evbuffer_add(evbuf, data, len); } void evtag_encode_int64(struct evbuffer *evbuf, ev_uint64_t number) { ev_uint8_t data[9]; int len = encode_int64_internal(data, number); evbuffer_add(evbuf, data, len); } /* * 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; int len = evbuffer_get_length(evbuf); ev_uint8_t *data; int count = 0, shift = 0, done = 0; /* * the encoding of a number is at most one byte more than its * storage size. however, it may also be much smaller. */ data = evbuffer_pullup( evbuf, len < sizeof(number) + 1 ? len : sizeof(number) + 1); 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); evtag_encode_int(evbuf, len); evbuffer_add(evbuf, (void *)data, len); } void evtag_marshal_buffer(struct evbuffer *evbuf, ev_uint32_t tag, struct evbuffer *data) { evtag_encode_tag(evbuf, tag); evtag_encode_int(evbuf, evbuffer_get_length(data)); evbuffer_add_buffer(evbuf, data); } /* Marshaling for integers */ void evtag_marshal_int(struct evbuffer *evbuf, ev_uint32_t tag, ev_uint32_t integer) { ev_uint8_t data[5]; int len = encode_int_internal(data, integer); evtag_encode_tag(evbuf, tag); evtag_encode_int(evbuf, len); evbuffer_add(evbuf, data, len); } void evtag_marshal_int64(struct evbuffer *evbuf, ev_uint32_t tag, ev_uint64_t integer) { ev_uint8_t data[9]; int len = encode_int64_internal(data, integer); evtag_encode_tag(evbuf, tag); evtag_encode_int(evbuf, len); evbuffer_add(evbuf, data, len); } 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) { ev_uint8_t data[10]; int len = encode_int_internal(data, tv->tv_sec); len += encode_int_internal(data + len, tv->tv_usec); evtag_marshal(evbuf, tag, data, len); } #define DECODE_INT_INTERNAL(number, maxnibbles, pnumber, evbuf, offset) \ do { \ ev_uint8_t *data; \ int len = evbuffer_get_length(evbuf) - offset; \ int nibbles = 0; \ \ if (len <= 0) \ return (-1); \ \ /* XXX(niels): faster? */ \ data = evbuffer_pullup(evbuf, offset + 1) + offset; \ \ nibbles = ((data[0] & 0xf0) >> 4) + 1; \ if (nibbles > maxnibbles || (nibbles >> 1) + 1 > len) \ return (-1); \ len = (nibbles >> 1) + 1; \ \ data = evbuffer_pullup(evbuf, offset + len) + offset; \ \ while (nibbles > 0) { \ number <<= 4; \ if (nibbles & 0x1) \ number |= data[nibbles >> 1] & 0x0f; \ else \ number |= (data[nibbles >> 1] & 0xf0) >> 4; \ nibbles--; \ } \ \ *pnumber = number; \ \ return (len); \ } while (0) /* Internal: decode an integer from an evbuffer, without draining it. * Only integers up to 32-bits are supported. * * @param evbuf the buffer to read from * @param offset an index into the buffer at which we should start reading. * @param pnumber a pointer to receive the integer. * @return The length of the number as encoded, or -1 on error. */ static int decode_int_internal(ev_uint32_t *pnumber, struct evbuffer *evbuf, int offset) { ev_uint32_t number = 0; DECODE_INT_INTERNAL(number, 8, pnumber, evbuf, offset); } static int decode_int64_internal(ev_uint64_t *pnumber, struct evbuffer *evbuf, int offset) { ev_uint64_t number = 0; DECODE_INT_INTERNAL(number, 16, pnumber, evbuf, offset); } int evtag_decode_int(ev_uint32_t *pnumber, struct evbuffer *evbuf) { int res = decode_int_internal(pnumber, evbuf, 0); if (res != -1) evbuffer_drain(evbuf, res); return (res == -1 ? -1 : 0); } int evtag_decode_int64(ev_uint64_t *pnumber, struct evbuffer *evbuf) { int res = decode_int64_internal(pnumber, evbuf, 0); if (res != -1) evbuffer_drain(evbuf, res); return (res == -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) { int res, len; len = decode_tag_internal(NULL, evbuf, 0 /* dodrain */); if (len == -1) return (-1); res = decode_int_internal(plength, evbuf, len); if (res == -1) return (-1); *plength += res + len; return (0); } int evtag_payload_length(struct evbuffer *evbuf, ev_uint32_t *plength) { int res, len; len = decode_tag_internal(NULL, evbuf, 0 /* dodrain */); if (len == -1) return (-1); res = decode_int_internal(plength, evbuf, len); if (res == -1) return (-1); return (0); } /* just unmarshals the header and returns the length of the remaining data */ int evtag_unmarshal_header(struct evbuffer *evbuf, ev_uint32_t *ptag) { ev_uint32_t len; if (decode_tag_internal(ptag, evbuf, 1 /* dodrain */) == -1) return (-1); if (evtag_decode_int(&len, evbuf) == -1) return (-1); if (evbuffer_get_length(evbuf) < len) return (-1); return (len); } int evtag_consume(struct evbuffer *evbuf) { int len; if ((len = evtag_unmarshal_header(evbuf, NULL)) == -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) { int len; if ((len = evtag_unmarshal_header(src, ptag)) == -1) return (-1); if (evbuffer_add(dst, evbuffer_pullup(src, len), 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; int result; if (decode_tag_internal(&tag, evbuf, 1 /* dodrain */) == -1) return (-1); if (need_tag != tag) return (-1); if (evtag_decode_int(&len, evbuf) == -1) return (-1); if (evbuffer_get_length(evbuf) < len) return (-1); result = decode_int_internal(pinteger, evbuf, 0); evbuffer_drain(evbuf, len); if (result < 0 || (size_t)result > len) /* XXX Should this be != rather than > ?*/ return (-1); else return result; } int evtag_unmarshal_int64(struct evbuffer *evbuf, ev_uint32_t need_tag, ev_uint64_t *pinteger) { ev_uint32_t tag; ev_uint32_t len; int result; if (decode_tag_internal(&tag, evbuf, 1 /* dodrain */) == -1) return (-1); if (need_tag != tag) return (-1); if (evtag_decode_int(&len, evbuf) == -1) return (-1); if (evbuffer_get_length(evbuf) < len) return (-1); result = decode_int64_internal(pinteger, evbuf, 0); evbuffer_drain(evbuf, len); if (result < 0 || (size_t)result > len) /* XXX Should this be != rather than > ?*/ return (-1); else return result; } /* 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; int tag_len; /* Now unmarshal a tag and check that it matches the tag we want */ if ((tag_len = evtag_unmarshal_header(src, &tag)) == -1 || tag != need_tag) return (-1); if (tag_len != len) return (-1); evbuffer_remove(src, data, len); return (0); } int evtag_unmarshal_string(struct evbuffer *evbuf, ev_uint32_t need_tag, char **pstring) { ev_uint32_t tag; int tag_len; if ((tag_len = evtag_unmarshal_header(evbuf, &tag)) == -1 || tag != need_tag) return (-1); *pstring = mm_malloc(tag_len + 1); if (*pstring == NULL) { event_warn("%s: malloc", __func__); return -1; } evbuffer_remove(evbuf, *pstring, tag_len); (*pstring)[tag_len] = '\0'; 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; int len, offset, offset2; int result = -1; if ((len = evtag_unmarshal_header(evbuf, &tag)) == -1) return (-1); if (tag != need_tag) goto done; if ((offset = decode_int_internal(&integer, evbuf, 0)) == -1) goto done; ptv->tv_sec = integer; if ((offset2 = decode_int_internal(&integer, evbuf, offset)) == -1) goto done; ptv->tv_usec = integer; if (offset + offset2 > len) /* XXX Should this be != instead of > ? */ goto done; result = 0; done: evbuffer_drain(evbuf, len); return result; }