link.h revision 1156
1697Spaul/* 21156Sjkh * Copyright (c) 1993 Paul Kranenburg 31156Sjkh * All rights reserved. 41156Sjkh * 51156Sjkh * Redistribution and use in source and binary forms, with or without 61156Sjkh * modification, are permitted provided that the following conditions 71156Sjkh * are met: 81156Sjkh * 1. Redistributions of source code must retain the above copyright 91156Sjkh * notice, this list of conditions and the following disclaimer. 101156Sjkh * 2. Redistributions in binary form must reproduce the above copyright 111156Sjkh * notice, this list of conditions and the following disclaimer in the 121156Sjkh * documentation and/or other materials provided with the distribution. 131156Sjkh * 3. All advertising materials mentioning features or use of this software 141156Sjkh * must display the following acknowledgement: 151156Sjkh * This product includes software developed by Paul Kranenburg. 161156Sjkh * 4. The name of the author may not be used to endorse or promote products 171156Sjkh * derived from this software withough specific prior written permission 181156Sjkh * 191156Sjkh * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 201156Sjkh * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 211156Sjkh * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 221156Sjkh * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 231156Sjkh * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 241156Sjkh * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 251156Sjkh * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 261156Sjkh * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 271156Sjkh * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 281156Sjkh * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 291156Sjkh * 301156Sjkh * $Id$ 311156Sjkh */ 321156Sjkh 331156Sjkh/* 34697Spaul * RRS section definitions. 35697Spaul * 361156Sjkh * The layout of some data structures defined in this header file is 371156Sjkh * such that we can provide compatibility with the SunOS 4.x shared 381156Sjkh * library scheme. 39697Spaul */ 40697Spaul 41697Spaul#ifndef _LINK_H_ 42697Spaul#define _LINK_H_ 43697Spaul 44697Spaul/* 451156Sjkh * A `Shared Object Descriptor' descibes a shared object that is needed 46697Spaul * to complete the link edit process of the object containing it. 471156Sjkh * A list of such objects (chained through `sod_next') is pointed at 481156Sjkh * by `sdt_sods' in the section_dispatch_table structure. 49697Spaul */ 50697Spaul 511156Sjkhstruct sod { /* Shared Object Descriptor */ 521156Sjkh long sod_name; /* name (relative to load address) */ 531156Sjkh u_int sod_library : 1, /* Searched for by library rules */ 541156Sjkh sod_reserved : 31; 551156Sjkh short sod_major; /* major version number */ 561156Sjkh short sod_minor; /* minor version number */ 571156Sjkh long sod_next; /* next sod */ 58697Spaul}; 59697Spaul 60697Spaul/* 611156Sjkh * `Shared Object Map's are used by the run-time link editor (ld.so) to 621156Sjkh * keep track of all shared objects loaded into a process' address space. 63697Spaul * These structures are only used at run-time and do not occur within 64697Spaul * the text or data segment of an executable or shared library. 65697Spaul */ 661156Sjkhstruct so_map { /* Shared Object Map */ 671156Sjkh caddr_t som_addr; /* Address at which object mapped */ 681156Sjkh char *som_path; /* Path to mmap'ed file */ 691156Sjkh struct so_map *som_next; /* Next map in chain */ 701156Sjkh struct sod *som_sod; /* Sod responsible for this map */ 711156Sjkh caddr_t som_sodbase; /* Base address of this sod */ 721156Sjkh u_int som_write : 1; /* Text is currently writable */ 731156Sjkh struct _dynamic *som_dynamic; /* _dynamic structure */ 741156Sjkh caddr_t som_spd; /* Private data */ 75697Spaul}; 76697Spaul 77697Spaul/* 78697Spaul * Symbol description with size. This is simply an `nlist' with 79697Spaul * one field (nz_size) added. 80697Spaul * Used to convey size information on items in the data segment 81697Spaul * of shared objects. An array of these live in the shared object's 821156Sjkh * text segment and is addressed by the `sdt_nzlist' field. 83697Spaul */ 84697Spaulstruct nzlist { 85697Spaul struct nlist nlist; 86697Spaul u_long nz_size; 87697Spaul#define nz_un nlist.n_un 88697Spaul#define nz_strx nlist.n_un.n_strx 89697Spaul#define nz_name nlist.n_un.n_name 90697Spaul#define nz_type nlist.n_type 91697Spaul#define nz_value nlist.n_value 92697Spaul#define nz_desc nlist.n_desc 93697Spaul#define nz_other nlist.n_other 94697Spaul}; 95697Spaul 961156Sjkh#define N_AUX(p) ((p)->n_other & 0xf) 971156Sjkh#define N_RESERVED(p) (((unsigned int)(p)->n_other >> 4) & 0xf) 981156Sjkh#define N_OTHER(r, v) (((unsigned int)(r) << 4) | ((v) & 0xf)) 991156Sjkh 1001156Sjkh#define AUX_OBJECT 1 1011156Sjkh#define AUX_FUNC 2 1021156Sjkh 1031156Sjkh 104697Spaul/* 1051156Sjkh * The `section_dispatch_table' structure contains offsets to various data 106697Spaul * structures needed to do run-time relocation. 107697Spaul */ 1081156Sjkhstruct section_dispatch_table { 1091156Sjkh struct so_map *sdt_loaded; /* List of loaded objects */ 1101156Sjkh long sdt_sods; /* List of shared objects descriptors */ 1111156Sjkh long sdt_filler1; /* Unused (was: search rules) */ 1121156Sjkh long sdt_got; /* Global offset table */ 1131156Sjkh long sdt_plt; /* Procedure linkage table */ 1141156Sjkh long sdt_rel; /* Relocation table */ 1151156Sjkh long sdt_hash; /* Symbol hash table */ 1161156Sjkh long sdt_nzlist; /* Symbol table itself */ 1171156Sjkh long sdt_filler2; /* Unused (was: stab_hash) */ 1181156Sjkh long sdt_buckets; /* Number of hash buckets */ 1191156Sjkh long sdt_strings; /* Symbol strings */ 1201156Sjkh long sdt_str_sz; /* Size of symbol strings */ 1211156Sjkh long sdt_text_sz; /* Size of text area */ 1221156Sjkh long sdt_plt_sz; /* Size of procedure linkage table */ 123697Spaul}; 124697Spaul 125697Spaul/* 1261156Sjkh * RRS symbol hash table, addressed by `sdt_hash' in section_dispatch_table. 127697Spaul * Used to quickly lookup symbols of the shared object by hashing 128697Spaul * on the symbol's name. `rh_symbolnum' is the index of the symbol 1291156Sjkh * in the shared object's symbol list (`sdt_nzlist'), `rh_next' is 130697Spaul * the next symbol in the hash bucket (in case of collisions). 131697Spaul */ 132697Spaulstruct rrs_hash { 1331156Sjkh int rh_symbolnum; /* Symbol number */ 1341156Sjkh int rh_next; /* Next hash entry */ 135697Spaul}; 136697Spaul 137697Spaul/* 138697Spaul * `rt_symbols' is used to keep track of run-time allocated commons 139697Spaul * and data items copied from shared objects. 140697Spaul */ 141697Spaulstruct rt_symbol { 1421156Sjkh struct nzlist *rt_sp; /* The symbol */ 1431156Sjkh struct rt_symbol *rt_next; /* Next in linear list */ 1441156Sjkh struct rt_symbol *rt_link; /* Next in bucket */ 1451156Sjkh caddr_t rt_srcaddr; /* Address of "master" copy */ 1461156Sjkh struct so_map *rt_smp; /* Originating map */ 147697Spaul}; 148697Spaul 149697Spaul/* 150697Spaul * Debugger interface structure. 151697Spaul */ 1521156Sjkhstruct so_debug { 1531156Sjkh int dd_version; /* Version # of interface */ 1541156Sjkh int dd_in_debugger; /* Set when run by debugger */ 1551156Sjkh int dd_sym_loaded; /* Run-time linking brought more 1561156Sjkh symbols into scope */ 1571156Sjkh char *dd_bpt_addr; /* Address of rtld-generated bpt */ 1581156Sjkh int dd_bpt_shadow; /* Original contents of bpt */ 1591156Sjkh struct rt_symbol *dd_cc; /* Allocated commons/copied data */ 160697Spaul}; 161697Spaul 162697Spaul/* 163697Spaul * Entry points into ld.so - user interface to the run-time linker. 164697Spaul */ 165697Spaulstruct ld_entry { 1661156Sjkh void *(*dlopen) __P((char *, int)); 1671156Sjkh int (*dlclose) __P((void *)); 1681156Sjkh void *(*dlsym) __P((void *, char *)); 1691156Sjkh int (*dlctl) __P((void *, int, void *)); 170697Spaul}; 171697Spaul 172697Spaul/* 1731156Sjkh * dlctl() commands 1741156Sjkh */ 1751156Sjkh#define DL_GETERRNO 1 1761156Sjkh 1771156Sjkh/* 1781156Sjkh * dl*() prototypes. 1791156Sjkh */ 1801156Sjkhextern void *dlopen __P((char *, int)); 1811156Sjkhextern int dlclose __P((void *)); 1821156Sjkhextern void *dlsym __P((void *, char *)); 1831156Sjkhextern int dlctl __P((void *, int, void *)); 1841156Sjkh 1851156Sjkh 1861156Sjkh/* 187697Spaul * This is the structure pointed at by the __DYNAMIC symbol if an 188697Spaul * executable requires the attention of the run-time link editor. 189697Spaul * __DYNAMIC is given the value zero if no run-time linking needs to 190697Spaul * be done (it is always present in shared objects). 1911156Sjkh * The union `d_un' provides for different versions of the dynamic 1921156Sjkh * linking mechanism (switched on by `d_version'). The last version 193697Spaul * used by Sun is 3. We leave some room here and go to version number 194697Spaul * 8 for NetBSD, the main difference lying in the support for the 195697Spaul * `nz_list' type of symbols. 196697Spaul */ 197697Spaul 1981156Sjkhstruct _dynamic { 1991156Sjkh int d_version; /* version # of this interface */ 2001156Sjkh struct so_debug *d_debug; 201697Spaul union { 2021156Sjkh struct section_dispatch_table *d_sdt; 2031156Sjkh } d_un; 2041156Sjkh struct ld_entry *d_entry; 205697Spaul}; 206697Spaul 207697Spaul#define LD_VERSION_SUN (3) 208697Spaul#define LD_VERSION_BSD (8) 209697Spaul#define LD_VERSION_NZLIST_P(v) ((v) >= 8) 210697Spaul 2111156Sjkh#define LD_GOT(x) ((x)->d_un.d_sdt->sdt_got) 2121156Sjkh#define LD_PLT(x) ((x)->d_un.d_sdt->sdt_plt) 2131156Sjkh#define LD_REL(x) ((x)->d_un.d_sdt->sdt_rel) 2141156Sjkh#define LD_SYMBOL(x) ((x)->d_un.d_sdt->sdt_nzlist) 2151156Sjkh#define LD_HASH(x) ((x)->d_un.d_sdt->sdt_hash) 2161156Sjkh#define LD_STRINGS(x) ((x)->d_un.d_sdt->sdt_strings) 2171156Sjkh#define LD_NEED(x) ((x)->d_un.d_sdt->sdt_sods) 2181156Sjkh#define LD_BUCKETS(x) ((x)->d_un.d_sdt->sdt_buckets) 219697Spaul 2201156Sjkh#define LD_GOTSZ(x) ((x)->d_un.d_sdt->sdt_plt - (x)->d_un.d_sdt->sdt_got) 2211156Sjkh#define LD_RELSZ(x) ((x)->d_un.d_sdt->sdt_hash - (x)->d_un.d_sdt->sdt_rel) 2221156Sjkh#define LD_HASHSZ(x) ((x)->d_un.d_sdt->sdt_nzlist - (x)->d_un.d_sdt->sdt_hash) 2231156Sjkh#define LD_STABSZ(x) ((x)->d_un.d_sdt->sdt_strings - (x)->d_un.d_sdt->sdt_nzlist) 2241156Sjkh#define LD_PLTSZ(x) ((x)->d_un.d_sdt->sdt_plt_sz) 2251156Sjkh#define LD_STRSZ(x) ((x)->d_un.d_sdt->sdt_str_sz) 2261156Sjkh#define LD_TEXTSZ(x) ((x)->d_un.d_sdt->sdt_text_sz) 227697Spaul 228697Spaul/* 2291156Sjkh * Interface to ld.so 230697Spaul */ 231697Spaulstruct crt_ldso { 232697Spaul int crt_ba; /* Base address of ld.so */ 233697Spaul int crt_dzfd; /* "/dev/zero" file decriptor (SunOS) */ 234697Spaul int crt_ldfd; /* ld.so file descriptor */ 2351156Sjkh struct _dynamic *crt_dp; /* Main's __DYNAMIC */ 236697Spaul char **crt_ep; /* environment strings */ 237697Spaul caddr_t crt_bp; /* Breakpoint if run from debugger */ 2381156Sjkh char *crt_prog; /* Program name */ 239697Spaul}; 240697Spaul 241697Spaul/* 242697Spaul * Version passed from crt0 to ld.so (1st argument to _rtld()). 243697Spaul */ 244697Spaul#define CRT_VERSION_SUN 1 245697Spaul#define CRT_VERSION_BSD 2 2461156Sjkh#define CRT_VERSION_BSD_2 2 2471156Sjkh#define CRT_VERSION_BSD_3 3 248697Spaul 249697Spaul 250697Spaul/* 251697Spaul * Maximum number of recognized shared object version numbers. 252697Spaul */ 253697Spaul#define MAXDEWEY 8 254697Spaul 255697Spaul/* 256697Spaul * Header of the hints file. 257697Spaul */ 258697Spaulstruct hints_header { 259697Spaul long hh_magic; 260697Spaul#define HH_MAGIC 011421044151 261697Spaul long hh_version; /* Interface version number */ 262697Spaul#define LD_HINTS_VERSION_1 1 263697Spaul long hh_hashtab; /* Location of hash table */ 264697Spaul long hh_nbucket; /* Number of buckets in hashtab */ 265697Spaul long hh_strtab; /* Location of strings */ 266697Spaul long hh_strtab_sz; /* Size of strings */ 267697Spaul long hh_ehints; /* End of hints (max offset in file) */ 268697Spaul}; 269697Spaul 270697Spaul#define HH_BADMAG(hdr) ((hdr).hh_magic != HH_MAGIC) 271697Spaul 272697Spaul/* 273697Spaul * Hash table element in hints file. 274697Spaul */ 275697Spaulstruct hints_bucket { 276697Spaul /* namex and pathx are indices into the string table */ 277697Spaul int hi_namex; /* Library name */ 278697Spaul int hi_pathx; /* Full path */ 279697Spaul int hi_dewey[MAXDEWEY]; /* The versions */ 280697Spaul int hi_ndewey; /* Number of version numbers */ 281697Spaul#define hi_major hi_dewey[0] 282697Spaul#define hi_minor hi_dewey[1] 283697Spaul int hi_next; /* Next in this bucket */ 284697Spaul}; 285697Spaul 286697Spaul#define _PATH_LD_HINTS "/var/run/ld.so.hints" 287697Spaul 288697Spaul#endif /* _LINK_H_ */ 289697Spaul 290