Annotation of src/include/link.h, Revision 1.1
1.1 ! deraadt 1: /* $NetBSD: link.h,v 1.9 1995/09/23 22:26:15 pk Exp $ */
! 2:
! 3: /*
! 4: * Copyright (c) 1993 Paul Kranenburg
! 5: * 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 Paul Kranenburg.
! 18: * 4. The name of the author may not be used to endorse or promote products
! 19: * derived from this software withough specific prior written permission
! 20: *
! 21: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
! 22: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
! 23: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
! 24: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
! 25: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
! 26: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
! 27: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
! 28: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
! 29: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
! 30: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
! 31: */
! 32:
! 33: /*
! 34: * RRS section definitions.
! 35: *
! 36: * The layout of some data structures defined in this header file is
! 37: * such that we can provide compatibility with the SunOS 4.x shared
! 38: * library scheme.
! 39: */
! 40:
! 41: #ifndef _LINK_H_
! 42: #define _LINK_H_
! 43:
! 44: /*
! 45: * A `Shared Object Descriptor' descibes a shared object that is needed
! 46: * to complete the link edit process of the object containing it.
! 47: * A list of such objects (chained through `sod_next') is pointed at
! 48: * by `sdt_sods' in the section_dispatch_table structure.
! 49: */
! 50:
! 51: struct sod { /* Shared Object Descriptor */
! 52: long sod_name; /* name (relative to load address) */
! 53: u_int sod_library : 1, /* Searched for by library rules */
! 54: sod_reserved : 31;
! 55: short sod_major; /* major version number */
! 56: short sod_minor; /* minor version number */
! 57: long sod_next; /* next sod */
! 58: };
! 59:
! 60: /*
! 61: * `Shared Object Map's are used by the run-time link editor (ld.so) to
! 62: * keep track of all shared objects loaded into a process' address space.
! 63: * These structures are only used at run-time and do not occur within
! 64: * the text or data segment of an executable or shared library.
! 65: */
! 66: struct so_map { /* Shared Object Map */
! 67: caddr_t som_addr; /* Address at which object mapped */
! 68: char *som_path; /* Path to mmap'ed file */
! 69: struct so_map *som_next; /* Next map in chain */
! 70: struct sod *som_sod; /* Sod responsible for this map */
! 71: caddr_t som_sodbase; /* Base address of this sod */
! 72: u_int som_write : 1; /* Text is currently writable */
! 73: struct _dynamic *som_dynamic; /* _dynamic structure */
! 74: caddr_t som_spd; /* Private data */
! 75: };
! 76:
! 77: /*
! 78: * Symbol description with size. This is simply an `nlist' with
! 79: * one field (nz_size) added.
! 80: * Used to convey size information on items in the data segment
! 81: * of shared objects. An array of these live in the shared object's
! 82: * text segment and is addressed by the `sdt_nzlist' field.
! 83: */
! 84: struct nzlist {
! 85: struct nlist nlist;
! 86: u_long nz_size;
! 87: #define nz_un nlist.n_un
! 88: #define nz_strx nlist.n_un.n_strx
! 89: #define nz_name nlist.n_un.n_name
! 90: #define nz_type nlist.n_type
! 91: #define nz_value nlist.n_value
! 92: #define nz_desc nlist.n_desc
! 93: #define nz_other nlist.n_other
! 94: };
! 95:
! 96: #define N_AUX(p) ((p)->n_other & 0xf)
! 97: #define N_BIND(p) (((unsigned int)(p)->n_other >> 4) & 0xf)
! 98: #define N_OTHER(r, v) (((unsigned int)(r) << 4) | ((v) & 0xf))
! 99:
! 100: #define AUX_OBJECT 1
! 101: #define AUX_FUNC 2
! 102: /*#define BIND_LOCAL 0 not used */
! 103: /*#define BIND_GLOBAL 1 not used */
! 104: #define BIND_WEAK 2
! 105:
! 106:
! 107: /*
! 108: * The `section_dispatch_table' structure contains offsets to various data
! 109: * structures needed to do run-time relocation.
! 110: */
! 111: struct section_dispatch_table {
! 112: struct so_map *sdt_loaded; /* List of loaded objects */
! 113: long sdt_sods; /* List of shared objects descriptors */
! 114: long sdt_paths; /* Library search paths */
! 115: long sdt_got; /* Global offset table */
! 116: long sdt_plt; /* Procedure linkage table */
! 117: long sdt_rel; /* Relocation table */
! 118: long sdt_hash; /* Symbol hash table */
! 119: long sdt_nzlist; /* Symbol table itself */
! 120: long sdt_filler2; /* Unused (was: stab_hash) */
! 121: long sdt_buckets; /* Number of hash buckets */
! 122: long sdt_strings; /* Symbol strings */
! 123: long sdt_str_sz; /* Size of symbol strings */
! 124: long sdt_text_sz; /* Size of text area */
! 125: long sdt_plt_sz; /* Size of procedure linkage table */
! 126: };
! 127:
! 128: /*
! 129: * RRS symbol hash table, addressed by `sdt_hash' in section_dispatch_table.
! 130: * Used to quickly lookup symbols of the shared object by hashing
! 131: * on the symbol's name. `rh_symbolnum' is the index of the symbol
! 132: * in the shared object's symbol list (`sdt_nzlist'), `rh_next' is
! 133: * the next symbol in the hash bucket (in case of collisions).
! 134: */
! 135: struct rrs_hash {
! 136: int rh_symbolnum; /* Symbol number */
! 137: int rh_next; /* Next hash entry */
! 138: };
! 139:
! 140: /*
! 141: * `rt_symbols' is used to keep track of run-time allocated commons
! 142: * and data items copied from shared objects.
! 143: */
! 144: struct rt_symbol {
! 145: struct nzlist *rt_sp; /* The symbol */
! 146: struct rt_symbol *rt_next; /* Next in linear list */
! 147: struct rt_symbol *rt_link; /* Next in bucket */
! 148: caddr_t rt_srcaddr; /* Address of "master" copy */
! 149: struct so_map *rt_smp; /* Originating map */
! 150: };
! 151:
! 152: /*
! 153: * Debugger interface structure.
! 154: */
! 155: struct so_debug {
! 156: int dd_version; /* Version # of interface */
! 157: int dd_in_debugger; /* Set when run by debugger */
! 158: int dd_sym_loaded; /* Run-time linking brought more
! 159: symbols into scope */
! 160: char *dd_bpt_addr; /* Address of rtld-generated bpt */
! 161: int dd_bpt_shadow; /* Original contents of bpt */
! 162: struct rt_symbol *dd_cc; /* Allocated commons/copied data */
! 163: };
! 164:
! 165: /*
! 166: * Entry points into ld.so - user interface to the run-time linker.
! 167: */
! 168: struct ld_entry {
! 169: void *(*dlopen) __P((char *, int));
! 170: int (*dlclose) __P((void *));
! 171: void *(*dlsym) __P((void *, char *));
! 172: int (*dlctl) __P((void *, int, void *));
! 173: void (*dlexit) __P((void));
! 174: void (*dlrsrvd[3]) __P((void));
! 175: };
! 176:
! 177: /*
! 178: * This is the structure pointed at by the __DYNAMIC symbol if an
! 179: * executable requires the attention of the run-time link editor.
! 180: * __DYNAMIC is given the value zero if no run-time linking needs to
! 181: * be done (it is always present in shared objects).
! 182: * The union `d_un' provides for different versions of the dynamic
! 183: * linking mechanism (switched on by `d_version'). The last version
! 184: * used by Sun is 3. We leave some room here and go to version number
! 185: * 8 for NetBSD, the main difference lying in the support for the
! 186: * `nz_list' type of symbols.
! 187: */
! 188:
! 189: struct _dynamic {
! 190: int d_version; /* version # of this interface */
! 191: struct so_debug *d_debug;
! 192: union {
! 193: struct section_dispatch_table *d_sdt;
! 194: } d_un;
! 195: struct ld_entry *d_entry; /* compat - now in crt_ldso */
! 196: };
! 197:
! 198: #define LD_VERSION_SUN (3)
! 199: #define LD_VERSION_BSD (8)
! 200: #define LD_VERSION_NZLIST_P(v) ((v) >= 8)
! 201:
! 202: #define LD_GOT(x) ((x)->d_un.d_sdt->sdt_got)
! 203: #define LD_PLT(x) ((x)->d_un.d_sdt->sdt_plt)
! 204: #define LD_REL(x) ((x)->d_un.d_sdt->sdt_rel)
! 205: #define LD_SYMBOL(x) ((x)->d_un.d_sdt->sdt_nzlist)
! 206: #define LD_HASH(x) ((x)->d_un.d_sdt->sdt_hash)
! 207: #define LD_STRINGS(x) ((x)->d_un.d_sdt->sdt_strings)
! 208: #define LD_NEED(x) ((x)->d_un.d_sdt->sdt_sods)
! 209: #define LD_BUCKETS(x) ((x)->d_un.d_sdt->sdt_buckets)
! 210: #define LD_PATHS(x) ((x)->d_un.d_sdt->sdt_paths)
! 211:
! 212: #define LD_GOTSZ(x) ((x)->d_un.d_sdt->sdt_plt - (x)->d_un.d_sdt->sdt_got)
! 213: #define LD_RELSZ(x) ((x)->d_un.d_sdt->sdt_hash - (x)->d_un.d_sdt->sdt_rel)
! 214: #define LD_HASHSZ(x) ((x)->d_un.d_sdt->sdt_nzlist - (x)->d_un.d_sdt->sdt_hash)
! 215: #define LD_STABSZ(x) ((x)->d_un.d_sdt->sdt_strings - (x)->d_un.d_sdt->sdt_nzlist)
! 216: #define LD_PLTSZ(x) ((x)->d_un.d_sdt->sdt_plt_sz)
! 217: #define LD_STRSZ(x) ((x)->d_un.d_sdt->sdt_str_sz)
! 218: #define LD_TEXTSZ(x) ((x)->d_un.d_sdt->sdt_text_sz)
! 219:
! 220: /*
! 221: * Interface to ld.so
! 222: */
! 223: struct crt_ldso {
! 224: int crt_ba; /* Base address of ld.so */
! 225: int crt_dzfd; /* "/dev/zero" file decriptor (SunOS) */
! 226: int crt_ldfd; /* ld.so file descriptor */
! 227: struct _dynamic *crt_dp; /* Main's __DYNAMIC */
! 228: char **crt_ep; /* environment strings */
! 229: caddr_t crt_bp; /* Breakpoint if run from debugger */
! 230: char *crt_prog; /* Program name (v3) */
! 231: char *crt_ldso; /* Link editor name (v4) */
! 232: struct ld_entry *crt_ldentry; /* dl*() access (v4) */
! 233: };
! 234:
! 235: /*
! 236: * Version passed from crt0 to ld.so (1st argument to _rtld()).
! 237: */
! 238: #define CRT_VERSION_SUN 1
! 239: #define CRT_VERSION_BSD_2 2
! 240: #define CRT_VERSION_BSD_3 3
! 241: #define CRT_VERSION_BSD_4 4
! 242:
! 243:
! 244: /*
! 245: * Maximum number of recognized shared object version numbers.
! 246: */
! 247: #define MAXDEWEY 8
! 248:
! 249: /*
! 250: * Header of the hints file.
! 251: */
! 252: struct hints_header {
! 253: long hh_magic;
! 254: #define HH_MAGIC 011421044151
! 255: long hh_version; /* Interface version number */
! 256: #define LD_HINTS_VERSION_1 1
! 257: long hh_hashtab; /* Location of hash table */
! 258: long hh_nbucket; /* Number of buckets in hashtab */
! 259: long hh_strtab; /* Location of strings */
! 260: long hh_strtab_sz; /* Size of strings */
! 261: long hh_ehints; /* End of hints (max offset in file) */
! 262: };
! 263:
! 264: #define HH_BADMAG(hdr) ((hdr).hh_magic != HH_MAGIC)
! 265:
! 266: /*
! 267: * Hash table element in hints file.
! 268: */
! 269: struct hints_bucket {
! 270: /* namex and pathx are indices into the string table */
! 271: int hi_namex; /* Library name */
! 272: int hi_pathx; /* Full path */
! 273: int hi_dewey[MAXDEWEY]; /* The versions */
! 274: int hi_ndewey; /* Number of version numbers */
! 275: #define hi_major hi_dewey[0]
! 276: #define hi_minor hi_dewey[1]
! 277: int hi_next; /* Next in this bucket */
! 278: };
! 279:
! 280: #define _PATH_LD_HINTS "/var/run/ld.so.hints"
! 281:
! 282: #endif /* _LINK_H_ */
! 283:
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