diff options
Diffstat (limited to 'src/coredump-util.c')
| -rw-r--r-- | src/coredump-util.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/src/coredump-util.c b/src/coredump-util.c new file mode 100644 index 0000000..468d54a --- /dev/null +++ b/src/coredump-util.c @@ -0,0 +1,219 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of libminidump. + + Copyright 2012 Lennart Poettering + + libminidump is free software; you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 of the + License, or (at your option) any later version. + + libminidump 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with libminidump; If not, see + <http://www.gnu.org/licenses/>. +***/ + +#include <errno.h> +#include <stdlib.h> +#include <string.h> +#include <assert.h> +#include <stdio.h> +#include <unistd.h> +#include <sys/param.h> + +#include "coredump-util.h" + +int coredump_read_header(int fd, ElfW(Ehdr) *header) { + ssize_t l; + + assert(fd >= 0); + assert(header); + + l = pread(fd, header, sizeof(*header), 0); + if (l < 0) + return -errno; + if (l != sizeof(*header)) + return -EIO; + + if (memcmp(header->e_ident, ELFMAG, SELFMAG) != 0) + return -EINVAL; + + if (header->e_type != ET_CORE) + return -EINVAL; + + if (header->e_ehsize != sizeof(ElfW(Ehdr))) + return -EINVAL; + + if (header->e_phentsize != sizeof(ElfW(Phdr))) + return -EINVAL; + +#if __WORDSIZE == 32 + if (header->e_ident[EI_CLASS] != ELFCLASS32) + return -EINVAL; +#elif __WORDSIZE == 64 + if (header->e_ident[EI_CLASS] != ELFCLASS64) + return -EINVAL; +#else +#error "Unknown word size." +#endif + +#if __BYTE_ORDER == __LITTLE_ENDIAN + if (header->e_ident[EI_DATA] != ELFDATA2LSB) + return -EINVAL; +#elif __BYTE_ORDER == __BIG_ENDIAN + if (header->e_ident[EI_DATA] != ELFDATA2MSB) + return -EINVAL; +#else +#error "Unknown endianess." +#endif + +#if defined(__i386) + if (header->e_machine != EM_386) + return -EINVAL; +#elif defined(__x86_64) + if (header->e_machine != EM_X86_64) + return -EINVAL; +#else +#error "Unknown machine." +#endif + + return 0; +} + +int coredump_read_segment_header(int fd, const ElfW(Ehdr) *header, unsigned long i, ElfW(Phdr) *segment) { + ssize_t l; + + assert(fd >= 0); + assert(header); + assert(segment); + + if (header->e_phoff == 0) + return -E2BIG; + + if (i >= header->e_phnum) + return -E2BIG; + + l = pread(fd, segment, sizeof(*segment), + header->e_phoff + i * header->e_phentsize); + + if (l < 0) + return -errno; + if (l != sizeof(*segment)) + return -EIO; + + return 0; +} + +int coredump_find_note_segment(int fd, const ElfW(Ehdr) *header, off_t *offset, off_t *length) { + unsigned long i; + int r; + + assert(fd >= 0); + assert(header); + assert(offset); + assert(length); + + for (i = 0; i < header->e_phnum; i++) { + ElfW(Phdr) segment; + + r = coredump_read_segment_header(fd, header, i, &segment); + if (r < 0) + return r; + + if (segment.p_type == PT_NOTE) { + *offset = segment.p_offset; + *length = segment.p_filesz; + + return 1; + } + } + + return 0; +} + +int coredump_read_memory(int fd, const ElfW(Ehdr) *header, unsigned long source, void *destination, size_t length) { + unsigned long i; + int r; + + assert(fd >= 0); + assert(header); + assert(destination); + assert(length > 0); + + for (i = 0; i < header->e_phnum; i++) { + ElfW(Phdr) segment; + ssize_t l; + + r = coredump_read_segment_header(fd, header, i, &segment); + if (r < 0) + return r; + + if (segment.p_type != PT_LOAD) + continue; + + if (source >= segment.p_vaddr + segment.p_filesz) + continue; + + if (source + length < segment.p_vaddr) + continue; + + /* We assume that what we are looking for lies + * entirely within one segment. */ + + if (source < segment.p_vaddr || + source + length > segment.p_vaddr + segment.p_filesz) + return -EIO; + + l = pread(fd, + (uint8_t*) destination, length, + segment.p_offset + (source - segment.p_vaddr)); + if (l < 0) + return -errno; + if ((size_t) l != length) + return -EIO; + + return 1; + } + + return 0; +} + +int coredump_next_note(int fd, off_t *offset, off_t *length, ElfW(Nhdr) *n, off_t *name, off_t *descriptor) { + ssize_t l; + off_t j; + + assert(fd >= 0); + assert(offset); + assert(length); + assert(n); + assert(name); + assert(descriptor); + + l = pread(fd, n, sizeof(*n), *offset); + if (l < 0) + return -errno; + if (l != sizeof(*n)) + return -EIO; + + j = sizeof(*n) + + roundup(n->n_namesz, sizeof(int)) + + roundup(n->n_descsz, sizeof(int)); + + if (j > *length) + return -EIO; + + *name = *offset + sizeof(*n); + *descriptor = *offset + sizeof(*n) + roundup(n->n_namesz, sizeof(int)); + + *offset += j; + *length -= j; + + return 0; +} |