diff options
Diffstat (limited to 'contrib/pgcrypto/mbuf.c')
-rw-r--r-- | contrib/pgcrypto/mbuf.c | 560 |
1 files changed, 560 insertions, 0 deletions
diff --git a/contrib/pgcrypto/mbuf.c b/contrib/pgcrypto/mbuf.c new file mode 100644 index 0000000..bc668a0 --- /dev/null +++ b/contrib/pgcrypto/mbuf.c @@ -0,0 +1,560 @@ +/* + * mbuf.c + * Memory buffer operations. + * + * Copyright (c) 2005 Marko Kreen + * 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. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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. + * + * contrib/pgcrypto/mbuf.c + */ + +#include "postgres.h" + +#include "mbuf.h" +#include "px.h" + +#define STEP (16*1024) + +struct MBuf +{ + uint8 *data; + uint8 *data_end; + uint8 *read_pos; + uint8 *buf_end; + bool no_write; + bool own_data; +}; + +int +mbuf_avail(MBuf *mbuf) +{ + return mbuf->data_end - mbuf->read_pos; +} + +int +mbuf_size(MBuf *mbuf) +{ + return mbuf->data_end - mbuf->data; +} + +int +mbuf_tell(MBuf *mbuf) +{ + return mbuf->read_pos - mbuf->data; +} + +int +mbuf_free(MBuf *mbuf) +{ + if (mbuf->own_data) + { + px_memset(mbuf->data, 0, mbuf->buf_end - mbuf->data); + pfree(mbuf->data); + } + pfree(mbuf); + return 0; +} + +static void +prepare_room(MBuf *mbuf, int block_len) +{ + uint8 *newbuf; + unsigned newlen; + + if (mbuf->data_end + block_len <= mbuf->buf_end) + return; + + newlen = (mbuf->buf_end - mbuf->data) + + ((block_len + STEP + STEP - 1) & -STEP); + + newbuf = repalloc(mbuf->data, newlen); + + mbuf->buf_end = newbuf + newlen; + mbuf->data_end = newbuf + (mbuf->data_end - mbuf->data); + mbuf->read_pos = newbuf + (mbuf->read_pos - mbuf->data); + mbuf->data = newbuf; +} + +int +mbuf_append(MBuf *dst, const uint8 *buf, int len) +{ + if (dst->no_write) + { + px_debug("mbuf_append: no_write"); + return PXE_BUG; + } + + prepare_room(dst, len); + + memcpy(dst->data_end, buf, len); + dst->data_end += len; + + return 0; +} + +MBuf * +mbuf_create(int len) +{ + MBuf *mbuf; + + if (!len) + len = 8192; + + mbuf = palloc(sizeof *mbuf); + mbuf->data = palloc(len); + mbuf->buf_end = mbuf->data + len; + mbuf->data_end = mbuf->data; + mbuf->read_pos = mbuf->data; + + mbuf->no_write = false; + mbuf->own_data = true; + + return mbuf; +} + +MBuf * +mbuf_create_from_data(uint8 *data, int len) +{ + MBuf *mbuf; + + mbuf = palloc(sizeof *mbuf); + mbuf->data = (uint8 *) data; + mbuf->buf_end = mbuf->data + len; + mbuf->data_end = mbuf->data + len; + mbuf->read_pos = mbuf->data; + + mbuf->no_write = true; + mbuf->own_data = false; + + return mbuf; +} + + +int +mbuf_grab(MBuf *mbuf, int len, uint8 **data_p) +{ + if (len > mbuf_avail(mbuf)) + len = mbuf_avail(mbuf); + + mbuf->no_write = true; + + *data_p = mbuf->read_pos; + mbuf->read_pos += len; + return len; +} + +int +mbuf_rewind(MBuf *mbuf) +{ + mbuf->read_pos = mbuf->data; + return 0; +} + +int +mbuf_steal_data(MBuf *mbuf, uint8 **data_p) +{ + int len = mbuf_size(mbuf); + + mbuf->no_write = true; + mbuf->own_data = false; + + *data_p = mbuf->data; + + mbuf->data = mbuf->data_end = mbuf->read_pos = mbuf->buf_end = NULL; + + return len; +} + +/* + * PullFilter + */ + +struct PullFilter +{ + PullFilter *src; + const PullFilterOps *op; + int buflen; + uint8 *buf; + int pos; + void *priv; +}; + +int +pullf_create(PullFilter **pf_p, const PullFilterOps *op, void *init_arg, PullFilter *src) +{ + PullFilter *pf; + void *priv; + int res; + + if (op->init != NULL) + { + res = op->init(&priv, init_arg, src); + if (res < 0) + return res; + } + else + { + priv = init_arg; + res = 0; + } + + pf = palloc0(sizeof(*pf)); + pf->buflen = res; + pf->op = op; + pf->priv = priv; + pf->src = src; + if (pf->buflen > 0) + { + pf->buf = palloc(pf->buflen); + pf->pos = 0; + } + else + { + pf->buf = NULL; + pf->pos = 0; + } + *pf_p = pf; + return 0; +} + +void +pullf_free(PullFilter *pf) +{ + if (pf->op->free) + pf->op->free(pf->priv); + + if (pf->buf) + { + px_memset(pf->buf, 0, pf->buflen); + pfree(pf->buf); + } + + px_memset(pf, 0, sizeof(*pf)); + pfree(pf); +} + +/* may return less data than asked, 0 means eof */ +int +pullf_read(PullFilter *pf, int len, uint8 **data_p) +{ + int res; + + if (pf->op->pull) + { + if (pf->buflen && len > pf->buflen) + len = pf->buflen; + res = pf->op->pull(pf->priv, pf->src, len, data_p, + pf->buf, pf->buflen); + } + else + res = pullf_read(pf->src, len, data_p); + return res; +} + +int +pullf_read_max(PullFilter *pf, int len, uint8 **data_p, uint8 *tmpbuf) +{ + int res, + total; + uint8 *tmp; + + res = pullf_read(pf, len, data_p); + if (res <= 0 || res == len) + return res; + + /* read was shorter, use tmpbuf */ + memcpy(tmpbuf, *data_p, res); + *data_p = tmpbuf; + len -= res; + total = res; + + while (len > 0) + { + res = pullf_read(pf, len, &tmp); + if (res < 0) + { + /* so the caller must clear only on success */ + px_memset(tmpbuf, 0, total); + return res; + } + if (res == 0) + break; + memcpy(tmpbuf + total, tmp, res); + total += res; + len -= res; + } + return total; +} + +/* + * caller wants exactly len bytes and don't bother with references + */ +int +pullf_read_fixed(PullFilter *src, int len, uint8 *dst) +{ + int res; + uint8 *p; + + res = pullf_read_max(src, len, &p, dst); + if (res < 0) + return res; + if (res != len) + { + px_debug("pullf_read_fixed: need=%d got=%d", len, res); + return PXE_PGP_CORRUPT_DATA; + } + if (p != dst) + memcpy(dst, p, len); + return 0; +} + +/* + * read from MBuf + */ +static int +pull_from_mbuf(void *arg, PullFilter *src, int len, + uint8 **data_p, uint8 *buf, int buflen) +{ + MBuf *mbuf = arg; + + return mbuf_grab(mbuf, len, data_p); +} + +static const struct PullFilterOps mbuf_reader = { + NULL, pull_from_mbuf, NULL +}; + +int +pullf_create_mbuf_reader(PullFilter **mp_p, MBuf *src) +{ + return pullf_create(mp_p, &mbuf_reader, src, NULL); +} + + +/* + * PushFilter + */ + +struct PushFilter +{ + PushFilter *next; + const PushFilterOps *op; + int block_size; + uint8 *buf; + int pos; + void *priv; +}; + +int +pushf_create(PushFilter **mp_p, const PushFilterOps *op, void *init_arg, PushFilter *next) +{ + PushFilter *mp; + void *priv; + int res; + + if (op->init != NULL) + { + res = op->init(next, init_arg, &priv); + if (res < 0) + return res; + } + else + { + priv = init_arg; + res = 0; + } + + mp = palloc0(sizeof(*mp)); + mp->block_size = res; + mp->op = op; + mp->priv = priv; + mp->next = next; + if (mp->block_size > 0) + { + mp->buf = palloc(mp->block_size); + mp->pos = 0; + } + else + { + mp->buf = NULL; + mp->pos = 0; + } + *mp_p = mp; + return 0; +} + +void +pushf_free(PushFilter *mp) +{ + if (mp->op->free) + mp->op->free(mp->priv); + + if (mp->buf) + { + px_memset(mp->buf, 0, mp->block_size); + pfree(mp->buf); + } + + px_memset(mp, 0, sizeof(*mp)); + pfree(mp); +} + +void +pushf_free_all(PushFilter *mp) +{ + PushFilter *tmp; + + while (mp) + { + tmp = mp->next; + pushf_free(mp); + mp = tmp; + } +} + +static int +wrap_process(PushFilter *mp, const uint8 *data, int len) +{ + int res; + + if (mp->op->push != NULL) + res = mp->op->push(mp->next, mp->priv, data, len); + else + res = pushf_write(mp->next, data, len); + if (res > 0) + return PXE_BUG; + return res; +} + +/* consumes all data, returns len on success */ +int +pushf_write(PushFilter *mp, const uint8 *data, int len) +{ + int need, + res; + + /* + * no buffering + */ + if (mp->block_size <= 0) + return wrap_process(mp, data, len); + + /* + * try to empty buffer + */ + need = mp->block_size - mp->pos; + if (need > 0) + { + if (len < need) + { + memcpy(mp->buf + mp->pos, data, len); + mp->pos += len; + return 0; + } + memcpy(mp->buf + mp->pos, data, need); + len -= need; + data += need; + } + + /* + * buffer full, process + */ + res = wrap_process(mp, mp->buf, mp->block_size); + if (res < 0) + return res; + mp->pos = 0; + + /* + * now process directly from data + */ + while (len > 0) + { + if (len > mp->block_size) + { + res = wrap_process(mp, data, mp->block_size); + if (res < 0) + return res; + data += mp->block_size; + len -= mp->block_size; + } + else + { + memcpy(mp->buf, data, len); + mp->pos += len; + break; + } + } + return 0; +} + +int +pushf_flush(PushFilter *mp) +{ + int res; + + while (mp) + { + if (mp->block_size > 0) + { + res = wrap_process(mp, mp->buf, mp->pos); + if (res < 0) + return res; + } + + if (mp->op->flush) + { + res = mp->op->flush(mp->next, mp->priv); + if (res < 0) + return res; + } + + mp = mp->next; + } + return 0; +} + + +/* + * write to MBuf + */ +static int +push_into_mbuf(PushFilter *next, void *arg, const uint8 *data, int len) +{ + int res = 0; + MBuf *mbuf = arg; + + if (len > 0) + res = mbuf_append(mbuf, data, len); + return res < 0 ? res : 0; +} + +static const struct PushFilterOps mbuf_filter = { + NULL, push_into_mbuf, NULL, NULL +}; + +int +pushf_create_mbuf_writer(PushFilter **res, MBuf *dst) +{ + return pushf_create(res, &mbuf_filter, dst, NULL); +} |