/* $OpenBSD: elfrdsetroot.c,v 1.22 2011/07/08 21:39:32 drahn Exp $ */ /* $NetBSD: rdsetroot.c,v 1.2 1995/10/13 16:38:39 gwr Exp $ */ /* * Copyright (c) 1994 Gordon W. Ross * Copyright (c) 1997 Per Fogelstrom. (ELF modifications) * 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. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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. */ /* * Copy a ramdisk image into the space reserved for it. * Kernel variables: rd_root_size, rd_root_image */ #include <sys/types.h> #include <sys/file.h> #include <sys/mman.h> #include <sys/stat.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <nlist.h> #include <sys/exec_elf.h> #include "elfrdsetroot.h" struct elfhdr head; /* Offsets relative to start of data segment. */ long rd_root_image_off, rd_root_size_off; /* value in the location at rd_root_size_off */ off_t rd_root_size_val; /* pointers to pieces of mapped file */ char *dataseg; /* parameters to mmap digged out from program header */ off_t mmap_off; size_t mmap_size; __dead void usage(void); int debug; struct elf_fn *elf_fn; int main(int argc, char *argv[]) { int ch, fd, n, xflag = 0, fsd; int found = 0, phsize; char *fs = NULL; char *file; u_int32_t *ip; while ((ch = getopt(argc, argv, "dx")) != -1) { switch (ch) { case 'd': debug = 1; break; case 'x': xflag = 1; break; default: usage(); } } argc -= optind; argv += optind; if (argc == 1) file = argv[0]; else if (argc == 2) { file = argv[0]; fs = argv[1]; } else usage(); fd = open(file, xflag ? O_RDONLY : O_RDWR, 0644); if (fd < 0) { perror(file); exit(1); } if (fs) { if (xflag) fsd = open(fs, O_RDWR | O_CREAT | O_TRUNC, 0644); else fsd = open(fs, O_RDONLY, 0644); } else { if (xflag) fsd = dup(STDOUT_FILENO); else fsd = dup(STDIN_FILENO); } if (fsd < 0) { perror(fs); exit(1); } n = read(fd, &head, sizeof(head)); if (n < sizeof(head)) { fprintf(stderr, "%s: reading header\n", file); exit(1); } if (!IS_ELF(head)) { fprintf(stderr, "%s: bad magic number\n", file); exit(1); } if (head.e_ident[EI_CLASS] == ELFCLASS32) { elf_fn = &ELF32_fn; } else if (head.e_ident[EI_CLASS] == ELFCLASS64) { elf_fn = &ELF64_fn; } else { fprintf(stderr, "%s: invalid elf, not 32 or 64 bit", file); exit(1); } elf_fn->locate_image(fd, &head, file, &rd_root_size_off, &rd_root_image_off, &mmap_off, &mmap_size); /* * Map in the whole data segment. * The file offset needs to be page aligned. */ dataseg = mmap(NULL, mmap_size, xflag ? PROT_READ : PROT_READ | PROT_WRITE, MAP_SHARED, fd, mmap_off); if (dataseg == MAP_FAILED) { fprintf(stderr, "%s: can not map data seg\n", file); perror(file); exit(1); } /* * Find value in the location: rd_root_size */ ip = (u_int32_t *) (dataseg + rd_root_size_off); rd_root_size_val = *ip; if (debug) fprintf(stderr, "rd_root_size val: 0x%llx (%lld blocks)\n", (unsigned long long)rd_root_size_val, (unsigned long long)rd_root_size_val >> 9); /* * Copy the symbol table and string table. */ if (debug) fprintf(stderr, "copying root image...\n"); if (xflag) { n = write(fsd, dataseg + rd_root_image_off, (size_t)rd_root_size_val); if (n != rd_root_size_val) { perror("write"); exit(1); } } else { struct stat sstat; if (fstat(fsd, &sstat) == -1) { perror("fstat"); exit(1); } if (S_ISREG(sstat.st_mode) && sstat.st_size > rd_root_size_val) { fprintf(stderr, "ramdisk too small 0x%llx 0x%llx\n", (unsigned long long)sstat.st_size, (unsigned long long)rd_root_size_val); exit(1); } n = read(fsd, dataseg + rd_root_image_off, (size_t)rd_root_size_val); if (n < 0) { perror("read"); exit(1); } msync(dataseg, mmap_size, 0); } if (debug) fprintf(stderr, "...copied %d bytes\n", n); exit(0); } __dead void usage(void) { extern char *__progname; fprintf(stderr, "usage: %s [-dx] bsd [fs]\n", __progname); exit(1); }