diff options
Diffstat (limited to 'depends/libxcb-cursor/xcb/parse_cursor_file.c')
| -rw-r--r-- | depends/libxcb-cursor/xcb/parse_cursor_file.c | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/depends/libxcb-cursor/xcb/parse_cursor_file.c b/depends/libxcb-cursor/xcb/parse_cursor_file.c new file mode 100644 index 0000000..21f72bf --- /dev/null +++ b/depends/libxcb-cursor/xcb/parse_cursor_file.c @@ -0,0 +1,198 @@ +/* + * vim:ts=4:sw=4:expandtab + * + * Copyright © 2013 Michael Stapelberg + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + * + * Except as contained in this notice, the names of the authors or their + * institutions shall not be used in advertising or otherwise to promote the + * sale, use or other dealings in this Software without prior written + * authorization from the authors. + * + */ +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <ctype.h> +#include <errno.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <unistd.h> +#include <stdbool.h> + +#ifdef HAVE_ENDIAN_H +#include <endian.h> +#endif +#ifdef HAVE_SYS_ENDIAN_H +#include <sys/endian.h> +#endif +#ifdef HAVE_SYS_BYTEORDER_H +#include <sys/byteorder.h> +# ifndef HAVE_LE32TOH +# define le32toh(x) LE_32(x) +# endif +#elif defined(HAVE_LIBKERN_OSBYTEORDER_H) +#include <libkern/OSByteOrder.h> +#define le32toh(x) OSSwapLittleToHostInt32(x) +#endif + +#include <xcb/xcb.h> + +#include "cursor.h" +#include "xcb_cursor.h" + +static uint32_t dist(const uint32_t a, const uint32_t b) { + return (a > b ? (a - b) : (b - a)); +} + +static uint32_t find_best_size(xcint_cursor_file_t *cf, const uint32_t target, uint32_t *nsizesp) { + uint32_t best = 0; + /* Amount of cursors with the best size */ + uint32_t nsizes = 0; + for (int n = 0; n < cf->header.ntoc; n++) { + const uint32_t size = cf->tocs[n].subtype; + + if (cf->tocs[n].type != XCURSOR_IMAGE_TYPE) + continue; + + /* If the distance is less to the target size, this is a better fit. */ + if (best == 0 || dist(size, target) < dist(best, target)) { + best = size; + nsizes = 0; + } + + if (size == best) + nsizes++; + } + + *nsizesp = nsizes; + return best; +} + +/* Returns true if and only if the read() call read the entirety of the data it + * was supposed to read. */ +static bool read_entirely(int fd, void *buf, size_t count) { + return read(fd, buf, count) == count; +} + +int parse_cursor_file(xcb_cursor_context_t *c, const int fd, xcint_image_t **images, int *nimg) { + /* Read the header, verify the magic value. */ + xcint_cursor_file_t cf; + uint32_t nsizes = 0; + uint32_t best = 0; + uint32_t skip = 0; + /* The amount of images stored in 'images', used when cleaning up. */ + int cnt = 0; + + if (!read_entirely(fd, &(cf.header), sizeof(xcint_file_header_t))) + return -EINVAL; + + cf.header.magic = le32toh(cf.header.magic); + cf.header.header = le32toh(cf.header.header); + cf.header.version = le32toh(cf.header.version); + cf.header.ntoc = le32toh(cf.header.ntoc); + + if (cf.header.magic != XCURSOR_MAGIC) + return -EINVAL; + + if ((skip = (cf.header.header - sizeof(xcint_file_header_t))) > 0) + if (lseek(fd, skip, SEEK_CUR) == EOF) + return -EINVAL; + + if (cf.header.ntoc > 0x10000) + return -EINVAL; + + /* Read the table of contents */ + cf.tocs = malloc(cf.header.ntoc * sizeof(xcint_file_toc_t)); + if (!read_entirely(fd, cf.tocs, cf.header.ntoc * sizeof(xcint_file_toc_t))) + goto error; + + for (int n = 0; n < cf.header.ntoc; n++) { + cf.tocs[n].type = le32toh(cf.tocs[n].type); + cf.tocs[n].subtype = le32toh(cf.tocs[n].subtype); + cf.tocs[n].position = le32toh(cf.tocs[n].position); + } + + /* No images? Invalid file. */ + if ((best = find_best_size(&cf, c->size, &nsizes)) == 0 || nsizes == 0) + goto error; + + *nimg = nsizes; + if ((*images = calloc(nsizes, sizeof(xcint_image_t))) == NULL) + goto error; + + for (int n = 0; n < cf.header.ntoc; n++) { + xcint_chunk_header_t chunk; + /* for convenience */ + xcint_image_t *i = &((*images)[cnt]); + uint32_t numpixels = 0; + uint32_t *p = NULL; + + if (cf.tocs[n].type != XCURSOR_IMAGE_TYPE || + cf.tocs[n].subtype != best) + continue; + + lseek(fd, cf.tocs[n].position, SEEK_SET); + if (!read_entirely(fd, &chunk, sizeof(xcint_chunk_header_t))) + goto error2; + chunk.header = le32toh(chunk.header); + chunk.type = le32toh(chunk.type); + chunk.subtype = le32toh(chunk.subtype); + chunk.version = le32toh(chunk.version); + /* Sanity check, as libxcursor does it. */ + if (chunk.type != cf.tocs[n].type || + chunk.subtype != cf.tocs[n].subtype) + goto error2; + if (!read_entirely(fd, i, sizeof(xcint_image_t) - sizeof(uint32_t*))) // TODO: better type + goto error2; + i->width = le32toh(i->width); + i->height = le32toh(i->height); + i->xhot = le32toh(i->xhot); + i->yhot = le32toh(i->yhot); + i->delay = le32toh(i->delay); + + /* Read the actual image data and convert it to host byte order */ + /* Catch integer overflows */ + if (((uint64_t)i->width) * i->height > UINT32_MAX) + goto error2; + numpixels = i->width * i->height; + i->pixels = malloc(numpixels * sizeof(uint32_t)); + /* With the malloc, one more image is eligible for cleanup later. */ + cnt++; + if (!read_entirely(fd, i->pixels, numpixels * sizeof(uint32_t))) + goto error2; + p = i->pixels; + for (int j = 0; j < numpixels; j++, p++) + *p = le32toh(*p); + } + + free(cf.tocs); + return 0; + +error2: + /* Free the memory for all images that were read so far. */ + for (int n = 0; n < cnt; n++) + free((*images)[n].pixels); + free(*images); +error: + *images = NULL; + free(cf.tocs); + return -EINVAL; +} |