--- /dev/null
+/* $OpenBSD: i386_nlist.c,v 1.1 2013/12/27 14:12:56 jsing Exp $ */
+/*
+ * Copyright (c) 1989, 1993
+ * The Regents of the University of California. 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. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
+ */
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <a.out.h> /* pulls in nlist.h */
+
+#ifdef _NLIST_DO_ELF
+#include <elf_abi.h>
+#endif
+
+#ifdef _NLIST_DO_ECOFF
+#include <sys/exec_ecoff.h>
+#endif
+
+int __fdnlist(int, struct nlist *);
+int __aout_fdnlist(int, struct nlist *);
+int __ecoff_fdnlist(int, struct nlist *);
+int __elf_fdnlist(int, struct nlist *);
+#ifdef _NLIST_DO_ELF
+int __elf_is_okay__(Elf_Ehdr *ehdr);
+#endif
+
+#define ISLAST(p) (p->n_un.n_name == 0 || p->n_un.n_name[0] == 0)
+
+#ifdef _NLIST_DO_AOUT
+int
+__aout_fdnlist(int fd, struct nlist *list)
+{
+ struct nlist *p, *s;
+ char *strtab;
+ off_t symoff, stroff;
+ u_long symsize;
+ int nent, cc;
+ int strsize, usemalloc = 0;
+ struct nlist nbuf[1024];
+ struct exec exec;
+
+ if (pread(fd, &exec, sizeof(exec), (off_t)0) != sizeof(exec) ||
+ N_BADMAG(exec) || exec.a_syms == 0)
+ return (-1);
+
+ stroff = N_STROFF(exec);
+ symoff = N_SYMOFF(exec);
+ symsize = exec.a_syms;
+
+ /* Read in the size of the string table. */
+ if (pread(fd, (void *)&strsize, sizeof(strsize), stroff) !=
+ sizeof(strsize))
+ return (-1);
+ else
+ stroff += sizeof(strsize);
+
+ /*
+ * Read in the string table. We try mmap, but that will fail
+ * for /dev/ksyms so fall back on malloc. Since OpenBSD's malloc(3)
+ * returns memory to the system on free this does not cause bloat.
+ */
+ strsize -= sizeof(strsize);
+ strtab = mmap(NULL, (size_t)strsize, PROT_READ, MAP_SHARED|MAP_FILE,
+ fd, stroff);
+ if (strtab == MAP_FAILED) {
+ usemalloc = 1;
+ if ((strtab = (char *)malloc(strsize)) == NULL)
+ return (-1);
+ errno = EIO;
+ if (pread(fd, strtab, strsize, stroff) != strsize) {
+ nent = -1;
+ goto aout_done;
+ }
+ }
+
+ /*
+ * clean out any left-over information for all valid entries.
+ * Type and value defined to be 0 if not found; historical
+ * versions cleared other and desc as well. Also figure out
+ * the largest string length so don't read any more of the
+ * string table than we have to.
+ *
+ * XXX clearing anything other than n_type and n_value violates
+ * the semantics given in the man page.
+ */
+ nent = 0;
+ for (p = list; !ISLAST(p); ++p) {
+ p->n_type = 0;
+ p->n_other = 0;
+ p->n_desc = 0;
+ p->n_value = 0;
+ ++nent;
+ }
+
+ while (symsize > 0) {
+ cc = MIN(symsize, sizeof(nbuf));
+ if (pread(fd, nbuf, cc, symoff) != cc)
+ break;
+ symsize -= cc;
+ symoff += cc;
+ for (s = nbuf; cc > 0; ++s, cc -= sizeof(*s)) {
+ char *sname = strtab + s->n_un.n_strx - sizeof(int);
+
+ if (s->n_un.n_strx == 0 || (s->n_type & N_STAB) != 0)
+ continue;
+ for (p = list; !ISLAST(p); p++) {
+ char *pname = p->n_un.n_name;
+
+ if (*sname != '_' && *pname == '_')
+ pname++;
+ if (!strcmp(sname, pname)) {
+ p->n_value = s->n_value;
+ p->n_type = s->n_type;
+ p->n_desc = s->n_desc;
+ p->n_other = s->n_other;
+ if (--nent <= 0)
+ break;
+ }
+ }
+ }
+ }
+aout_done:
+ if (usemalloc)
+ free(strtab);
+ else
+ munmap(strtab, strsize);
+ return (nent);
+}
+#endif /* _NLIST_DO_AOUT */
+
+#ifdef _NLIST_DO_ECOFF
+#define check(off, size) ((off < 0) || (off + size > mappedsize))
+#define BAD do { rv = -1; goto out; } while (0)
+#define BADUNMAP do { rv = -1; goto unmap; } while (0)
+
+int
+__ecoff_fdnlist(int fd, struct nlist *list)
+{
+ struct nlist *p;
+ struct ecoff_exechdr *exechdrp;
+ struct ecoff_symhdr *symhdrp;
+ struct ecoff_extsym *esyms;
+ struct stat st;
+ char *mappedfile;
+ size_t mappedsize;
+ u_long symhdroff, extstroff;
+ u_int symhdrsize;
+ int rv, nent;
+ long i, nesyms;
+
+ rv = -3;
+
+ if (fstat(fd, &st) < 0)
+ BAD;
+ if (st.st_size > SIZE_T_MAX) {
+ errno = EFBIG;
+ BAD;
+ }
+ mappedsize = st.st_size;
+ mappedfile = mmap(NULL, mappedsize, PROT_READ, MAP_SHARED|MAP_FILE,
+ fd, 0);
+ if (mappedfile == MAP_FAILED)
+ BAD;
+
+ if (check(0, sizeof *exechdrp))
+ BADUNMAP;
+ exechdrp = (struct ecoff_exechdr *)&mappedfile[0];
+
+ if (ECOFF_BADMAG(exechdrp))
+ BADUNMAP;
+
+ symhdroff = exechdrp->f.f_symptr;
+ symhdrsize = exechdrp->f.f_nsyms;
+
+ if (check(symhdroff, sizeof *symhdrp) ||
+ sizeof *symhdrp != symhdrsize)
+ BADUNMAP;
+ symhdrp = (struct ecoff_symhdr *)&mappedfile[symhdroff];
+
+ nesyms = symhdrp->esymMax;
+ if (check(symhdrp->cbExtOffset, nesyms * sizeof *esyms))
+ BADUNMAP;
+ esyms = (struct ecoff_extsym *)&mappedfile[symhdrp->cbExtOffset];
+ extstroff = symhdrp->cbSsExtOffset;
+
+ /*
+ * clean out any left-over information for all valid entries.
+ * Type and value defined to be 0 if not found; historical
+ * versions cleared other and desc as well.
+ *
+ * XXX clearing anything other than n_type and n_value violates
+ * the semantics given in the man page.
+ */
+ nent = 0;
+ for (p = list; !ISLAST(p); ++p) {
+ p->n_type = 0;
+ p->n_other = 0;
+ p->n_desc = 0;
+ p->n_value = 0;
+ ++nent;
+ }
+
+ for (i = 0; i < nesyms; i++) {
+ for (p = list; !ISLAST(p); p++) {
+ char *nlistname;
+ char *symtabname;
+
+ nlistname = p->n_un.n_name;
+ if (*nlistname == '_')
+ nlistname++;
+ symtabname =
+ &mappedfile[extstroff + esyms[i].es_strindex];
+
+ if (!strcmp(symtabname, nlistname)) {
+ p->n_value = esyms[i].es_value;
+ p->n_type = N_EXT; /* XXX */
+ p->n_desc = 0; /* XXX */
+ p->n_other = 0; /* XXX */
+ if (--nent <= 0)
+ break;
+ }
+ }
+ }
+ rv = nent;
+
+unmap:
+ munmap(mappedfile, mappedsize);
+out:
+ return (rv);
+}
+#endif /* _NLIST_DO_ECOFF */
+
+#ifdef _NLIST_DO_ELF
+/*
+ * __elf_is_okay__ - Determine if ehdr really
+ * is ELF and valid for the target platform.
+ *
+ * WARNING: This is NOT a ELF ABI function and
+ * as such its use should be restricted.
+ */
+int
+__elf_is_okay__(Elf_Ehdr *ehdr)
+{
+ int retval = 0;
+ /*
+ * We need to check magic, class size, endianess,
+ * and version before we look at the rest of the
+ * Elf_Ehdr structure. These few elements are
+ * represented in a machine independent fashion.
+ */
+
+ /*
+ * We are constructing a 32-bit executable. So we can't
+ * use the libc nlist.c, which would be upset. Manually
+ * check for the i386 values for EI_CLASS and e_machine.
+ */
+
+ if (IS_ELF(*ehdr) &&
+ ehdr->e_ident[EI_CLASS] == ELFCLASS32 &&
+ ehdr->e_ident[EI_DATA] == ELF_TARG_DATA &&
+ ehdr->e_ident[EI_VERSION] == ELF_TARG_VER) {
+
+ /* Now check the machine dependant header */
+ if (ehdr->e_machine == EM_386 &&
+ ehdr->e_version == ELF_TARG_VER)
+ retval = 1;
+ }
+
+ return retval;
+}
+
+int
+__elf_fdnlist(int fd, struct nlist *list)
+{
+ struct nlist *p;
+ caddr_t strtab;
+ Elf_Off symoff = 0, symstroff = 0;
+ Elf_Word symsize = 0, symstrsize = 0;
+ Elf_Sword nent, cc, i;
+ Elf_Sym sbuf[1024];
+ Elf_Sym *s;
+ Elf_Ehdr ehdr;
+ Elf_Shdr *shdr = NULL;
+ Elf_Word shdr_size;
+ struct stat st;
+ int usemalloc = 0;
+
+ /* Make sure obj is OK */
+ if (pread(fd, &ehdr, sizeof(Elf_Ehdr), (off_t)0) != sizeof(Elf_Ehdr) ||
+ !__elf_is_okay__(&ehdr) || fstat(fd, &st) < 0)
+ return (-1);
+
+ /* calculate section header table size */
+ shdr_size = ehdr.e_shentsize * ehdr.e_shnum;
+
+ /* mmap section header table */
+ shdr = (Elf_Shdr *)mmap(NULL, (size_t)shdr_size, PROT_READ,
+ MAP_SHARED|MAP_FILE, fd, (off_t) ehdr.e_shoff);
+ if (shdr == MAP_FAILED) {
+ usemalloc = 1;
+ if ((shdr = malloc(shdr_size)) == NULL)
+ return (-1);
+
+ if (pread(fd, shdr, shdr_size, (off_t)ehdr.e_shoff) != shdr_size) {
+ free(shdr);
+ return (-1);
+ }
+ }
+
+ /*
+ * Find the symbol table entry and its corresponding
+ * string table entry. Version 1.1 of the ABI states
+ * that there is only one symbol table but that this
+ * could change in the future.
+ */
+ for (i = 0; i < ehdr.e_shnum; i++) {
+ if (shdr[i].sh_type == SHT_SYMTAB) {
+ symoff = shdr[i].sh_offset;
+ symsize = shdr[i].sh_size;
+ symstroff = shdr[shdr[i].sh_link].sh_offset;
+ symstrsize = shdr[shdr[i].sh_link].sh_size;
+ break;
+ }
+ }
+
+ /* Flush the section header table */
+ if (usemalloc)
+ free(shdr);
+ else
+ munmap((caddr_t)shdr, shdr_size);
+
+ /*
+ * Map string table into our address space. This gives us
+ * an easy way to randomly access all the strings, without
+ * making the memory allocation permanent as with malloc/free
+ * (i.e., munmap will return it to the system).
+ */
+ if (usemalloc) {
+ if ((strtab = malloc(symstrsize)) == NULL)
+ return (-1);
+ if (pread(fd, strtab, symstrsize, (off_t)symstroff) != symstrsize) {
+ free(strtab);
+ return (-1);
+ }
+ } else {
+ strtab = mmap(NULL, (size_t)symstrsize, PROT_READ,
+ MAP_SHARED|MAP_FILE, fd, (off_t) symstroff);
+ if (strtab == MAP_FAILED)
+ return (-1);
+ }
+ /*
+ * clean out any left-over information for all valid entries.
+ * Type and value defined to be 0 if not found; historical
+ * versions cleared other and desc as well. Also figure out
+ * the largest string length so don't read any more of the
+ * string table than we have to.
+ *
+ * XXX clearing anything other than n_type and n_value violates
+ * the semantics given in the man page.
+ */
+ nent = 0;
+ for (p = list; !ISLAST(p); ++p) {
+ p->n_type = 0;
+ p->n_other = 0;
+ p->n_desc = 0;
+ p->n_value = 0;
+ ++nent;
+ }
+
+ /* Don't process any further if object is stripped. */
+ /* ELFism - dunno if stripped by looking at header */
+ if (symoff == 0)
+ goto elf_done;
+
+ while (symsize > 0) {
+ cc = MIN(symsize, sizeof(sbuf));
+ if (pread(fd, sbuf, cc, (off_t)symoff) != cc)
+ break;
+ symsize -= cc;
+ symoff += cc;
+ for (s = sbuf; cc > 0; ++s, cc -= sizeof(*s)) {
+ int soff = s->st_name;
+
+ if (soff == 0)
+ continue;
+ for (p = list; !ISLAST(p); p++) {
+ char *sym;
+
+ /*
+ * First we check for the symbol as it was
+ * provided by the user. If that fails
+ * and the first char is an '_', skip over
+ * the '_' and try again.
+ * XXX - What do we do when the user really
+ * wants '_foo' and the are symbols
+ * for both 'foo' and '_foo' in the
+ * table and 'foo' is first?
+ */
+ sym = p->n_un.n_name;
+ if (strcmp(&strtab[soff], sym) != 0 &&
+ (sym[0] != '_' ||
+ strcmp(&strtab[soff], sym + 1) != 0))
+ continue;
+
+ p->n_value = s->st_value;
+
+ /* XXX - type conversion */
+ /* is pretty rude. */
+ switch(ELF_ST_TYPE(s->st_info)) {
+ case STT_NOTYPE:
+ switch (s->st_shndx) {
+ case SHN_UNDEF:
+ p->n_type = N_UNDF;
+ break;
+ case SHN_ABS:
+ p->n_type = N_ABS;
+ break;
+ case SHN_COMMON:
+ p->n_type = N_COMM;
+ break;
+ default:
+ p->n_type = N_COMM | N_EXT;
+ break;
+ }
+ break;
+ case STT_OBJECT:
+ p->n_type = N_DATA;
+ break;
+ case STT_FUNC:
+ p->n_type = N_TEXT;
+ break;
+ case STT_FILE:
+ p->n_type = N_FN;
+ break;
+ }
+ if (ELF_ST_BIND(s->st_info) ==
+ STB_LOCAL)
+ p->n_type = N_EXT;
+ p->n_desc = 0;
+ p->n_other = 0;
+ if (--nent <= 0)
+ break;
+ }
+ }
+ }
+elf_done:
+ if (usemalloc)
+ free(strtab);
+ else
+ munmap(strtab, symstrsize);
+ return (nent);
+}
+#endif /* _NLIST_DO_ELF */
+
+
+static struct nlist_handlers {
+ int (*fn)(int fd, struct nlist *list);
+} nlist_fn[] = {
+#ifdef _NLIST_DO_AOUT
+ { __aout_fdnlist },
+#endif
+#ifdef _NLIST_DO_ELF
+ { __elf_fdnlist },
+#endif
+#ifdef _NLIST_DO_ECOFF
+ { __ecoff_fdnlist },
+#endif
+};
+
+int
+__fdnlist(int fd, struct nlist *list)
+{
+ int n = -1, i;
+
+ for (i = 0; i < (int)(sizeof(nlist_fn)/sizeof(nlist_fn[0])); i++) {
+ n = (nlist_fn[i].fn)(fd, list);
+ if (n != -1)
+ break;
+ }
+ return (n);
+}
+
+
+int
+nlist(const char *name, struct nlist *list)
+{
+ int fd, n;
+
+ fd = open(name, O_RDONLY, 0);
+ if (fd < 0)
+ return (-1);
+ n = __fdnlist(fd, list);
+ (void)close(fd);
+ return (n);
+}
projects / openbsd / commitdiff