From e82d74f89809c6c01f71168b3b8fdcf490e93fa7 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Wed, 13 Oct 2010 21:17:51 +0200 Subject: Initial import --- blob.c | 177 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 177 insertions(+) create mode 100644 blob.c (limited to 'blob.c') diff --git a/blob.c b/blob.c new file mode 100644 index 0000000..823eb24 --- /dev/null +++ b/blob.c @@ -0,0 +1,177 @@ +/* + * blob - library for generating/parsing tagged binary data + * + * Copyright (C) 2010 Felix Fietkau + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License version 2.1 + * as published by the Free Software Foundation + * + * This program 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. + */ + +#include "blob.h" + +static bool +blob_buffer_grow(struct blob_buf *buf, int minlen) +{ + buf->buflen += ((minlen / 256) + 1) * 256; + buf->buf = realloc(buf->buf, buf->buflen); + return !!buf->buf; +} + +static void +blob_init(struct blob_attr *attr, int id, unsigned int len) +{ + len &= BLOB_ATTR_LEN_MASK; + len |= (id << BLOB_ATTR_ID_SHIFT) & BLOB_ATTR_ID_MASK; + attr->id_len = cpu_to_be32(len); +} + +static inline struct blob_attr * +offset_to_attr(struct blob_buf *buf, int offset) +{ + void *ptr = (char *)buf->buf + offset; + return ptr; +} + +static inline int +attr_to_offset(struct blob_buf *buf, struct blob_attr *attr) +{ + return (char *)attr - (char *) buf->buf; +} + +static struct blob_attr * +blob_add(struct blob_buf *buf, struct blob_attr *pos, int id, int payload) +{ + int offset = attr_to_offset(buf, pos); + int required = (offset + sizeof(struct blob_attr) + payload) - buf->buflen; + struct blob_attr *attr; + + if (required > 0) { + int offset_head = attr_to_offset(buf, buf->head); + + if (!buf->grow || !buf->grow(buf, required)) + return NULL; + + buf->head = offset_to_attr(buf, offset_head); + attr = offset_to_attr(buf, offset); + } else { + attr = pos; + } + + blob_init(attr, id, payload + sizeof(struct blob_attr)); + return attr; +} + +int +blob_buf_init(struct blob_buf *buf, int id) +{ + if (!buf->grow) + buf->grow = blob_buffer_grow; + + buf->head = buf->buf; + if (blob_add(buf, buf->buf, id, 0) == NULL) + return -ENOMEM; + + return 0; +} + +struct blob_attr * +blob_new(struct blob_buf *buf, int id, int payload) +{ + struct blob_attr *attr; + + attr = blob_add(buf, blob_next(buf->head), id, payload); + if (!attr) + return NULL; + + blob_set_raw_len(buf->head, blob_pad_len(buf->head) + blob_pad_len(attr)); + return attr; +} + +struct blob_attr * +blob_put(struct blob_buf *buf, int id, const void *ptr, int len) +{ + struct blob_attr *attr; + + attr = blob_new(buf, id, len); + if (!attr) + return NULL; + + if (ptr) + memcpy(blob_data(attr), ptr, len); + return attr; +} + +void * +blob_nest_start(struct blob_buf *buf, int id) +{ + unsigned long offset = attr_to_offset(buf, buf->head); + buf->head = blob_new(buf, id, 0); + return (void *) offset; +} + +void +blob_nest_end(struct blob_buf *buf, void *cookie) +{ + struct blob_attr *attr = offset_to_attr(buf, (unsigned long) cookie); + blob_set_raw_len(attr, blob_pad_len(attr) + blob_len(buf->head)); + buf->head = attr; +} + +static const int blob_type_minlen[BLOB_ATTR_LAST] = { + [BLOB_ATTR_STRING] = 1, + [BLOB_ATTR_INT8] = sizeof(uint8_t), + [BLOB_ATTR_INT16] = sizeof(uint16_t), + [BLOB_ATTR_INT32] = sizeof(uint32_t), + [BLOB_ATTR_INT64] = sizeof(uint64_t), +}; + +int +blob_parse(struct blob_attr *attr, struct blob_attr **data, struct blob_attr_info *info, int max) +{ + struct blob_attr *pos; + int found = 0; + int rem; + + memset(data, 0, sizeof(struct blob_attr *) * max); + blob_for_each_attr(pos, attr, rem) { + int id = blob_id(pos); + int len = blob_len(pos); + + if (id >= max) + continue; + + if (info) { + int type = info[id].type; + if (type < BLOB_ATTR_LAST) { + if (type >= BLOB_ATTR_INT8 && type <= BLOB_ATTR_INT64) { + if (len != blob_type_minlen[type]) + continue; + } else { + if (len < blob_type_minlen[type]) + continue; + } + } + + if (info[id].minlen && len < info[id].minlen) + continue; + + if (info[id].maxlen && len > info[id].maxlen) + continue; + + if (info[id].validate && !info[id].validate(&info[id], attr)) + continue; + } + + if (!data[id]) + found++; + + data[id] = pos; + } + return found; +} -- cgit v1.2.3