1 /* $NetBSD: nlist.c,v 1.5 1995/02/27 04:35:29 cgd Exp $ */ 2 3 /* 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #if defined(LIBC_SCCS) && !defined(lint) 37 #if 0 38 static char sccsid[] = "@(#)nlist.c 8.1 (Berkeley) 6/4/93"; 39 #else 40 static char rcsid[] = "$NetBSD: nlist.c,v 1.5 1995/02/27 04:35:29 cgd Exp $"; 41 #endif 42 #endif /* LIBC_SCCS and not lint */ 43 44 #include <sys/param.h> 45 #include <sys/mman.h> 46 #include <sys/stat.h> 47 #include <sys/file.h> 48 49 #include <errno.h> 50 #include <a.out.h> 51 #include <stdio.h> 52 #include <string.h> 53 #include <unistd.h> 54 55 int 56 nlist(name, list) 57 const char *name; 58 struct nlist *list; 59 { 60 int fd, n; 61 62 fd = open(name, O_RDONLY, 0); 63 if (fd < 0) 64 return (-1); 65 n = __fdnlist(fd, list); 66 (void)close(fd); 67 return (n); 68 } 69 70 #define ISLAST(p) (p->n_un.n_name == 0 || p->n_un.n_name[0] == 0) 71 72 int 73 __fdnlist(fd, list) 74 register int fd; 75 register struct nlist *list; 76 { 77 register struct nlist *p, *s; 78 register caddr_t strtab; 79 register off_t stroff, symoff; 80 register u_long symsize; 81 register int nent, cc; 82 size_t strsize; 83 struct nlist nbuf[1024]; 84 struct exec exec; 85 struct stat st; 86 87 if (lseek(fd, (off_t)0, SEEK_SET) == -1 || 88 read(fd, &exec, sizeof(exec)) != sizeof(exec) || 89 N_BADMAG(exec) || fstat(fd, &st) < 0) 90 return (-1); 91 92 symoff = N_SYMOFF(exec); 93 symsize = exec.a_syms; 94 stroff = symoff + symsize; 95 96 /* Check for files too large to mmap. */ 97 if (st.st_size - stroff > SIZE_T_MAX) { 98 errno = EFBIG; 99 return (-1); 100 } 101 /* 102 * Map string table into our address space. This gives us 103 * an easy way to randomly access all the strings, without 104 * making the memory allocation permanent as with malloc/free 105 * (i.e., munmap will return it to the system). 106 */ 107 strsize = st.st_size - stroff; 108 strtab = mmap(NULL, (size_t)strsize, PROT_READ, 0, fd, stroff); 109 if (strtab == (char *)-1) 110 return (-1); 111 /* 112 * clean out any left-over information for all valid entries. 113 * Type and value defined to be 0 if not found; historical 114 * versions cleared other and desc as well. Also figure out 115 * the largest string length so don't read any more of the 116 * string table than we have to. 117 * 118 * XXX clearing anything other than n_type and n_value violates 119 * the semantics given in the man page. 120 */ 121 nent = 0; 122 for (p = list; !ISLAST(p); ++p) { 123 p->n_type = 0; 124 p->n_other = 0; 125 p->n_desc = 0; 126 p->n_value = 0; 127 ++nent; 128 } 129 if (lseek(fd, symoff, SEEK_SET) == -1) 130 return (-1); 131 132 while (symsize > 0) { 133 cc = MIN(symsize, sizeof(nbuf)); 134 if (read(fd, nbuf, cc) != cc) 135 break; 136 symsize -= cc; 137 for (s = nbuf; cc > 0; ++s, cc -= sizeof(*s)) { 138 register int soff = s->n_un.n_strx; 139 140 if (soff == 0 || (s->n_type & N_STAB) != 0) 141 continue; 142 for (p = list; !ISLAST(p); p++) 143 if (!strcmp(&strtab[soff], p->n_un.n_name)) { 144 p->n_value = s->n_value; 145 p->n_type = s->n_type; 146 p->n_desc = s->n_desc; 147 p->n_other = s->n_other; 148 if (--nent <= 0) 149 break; 150 } 151 } 152 } 153 munmap(strtab, strsize); 154 return (nent); 155 } 156