Edit
IABSD.fr/xenocara/lib/xcb-util-cursor/cursor/parse_cursor_file.c
dcoppa
- lib/xcb-util-cursor/cursor/parse_cursor_file.c
-
/* * 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> # ifndef HAVE_LE32TOH # define le32toh(x) letoh32(x) # endif #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; }