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