diff options
author | markm <markm@FreeBSD.org> | 1997-09-04 06:04:33 +0000 |
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committer | markm <markm@FreeBSD.org> | 1997-09-04 06:04:33 +0000 |
commit | a8a89cfaf983bc64f4b42f7c35209a5a36dd0fe8 (patch) | |
tree | 0b84977f19022a965f8c6145f067f951173f6290 /crypto/kerberosIV/lib/kafs/dlfcn.c | |
download | FreeBSD-src-a8a89cfaf983bc64f4b42f7c35209a5a36dd0fe8.zip FreeBSD-src-a8a89cfaf983bc64f4b42f7c35209a5a36dd0fe8.tar.gz |
Initial import of KTH eBones. This has been cleaned up to only include
the "core" Kerberos functionality. The rest of the userland will get their
own changes later.
Diffstat (limited to 'crypto/kerberosIV/lib/kafs/dlfcn.c')
-rw-r--r-- | crypto/kerberosIV/lib/kafs/dlfcn.c | 570 |
1 files changed, 570 insertions, 0 deletions
diff --git a/crypto/kerberosIV/lib/kafs/dlfcn.c b/crypto/kerberosIV/lib/kafs/dlfcn.c new file mode 100644 index 0000000..3f4de92 --- /dev/null +++ b/crypto/kerberosIV/lib/kafs/dlfcn.c @@ -0,0 +1,570 @@ +/* + * @(#)dlfcn.c 1.11 revision of 96/04/10 20:12:51 + * This is an unpublished work copyright (c) 1992 HELIOS Software GmbH + * 30159 Hannover, Germany + */ + +/* + * Changes marked with `--jwe' were made on April 7 1996 by John W. Eaton + * <jwe@bevo.che.wisc.edu> to support g++ and/or use with Octave. + */ + +/* + * This makes my life easier with Octave. --jwe + */ +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include <stdio.h> +#include <errno.h> +#include <string.h> +#include <stdlib.h> +#include <sys/types.h> +#include <sys/ldr.h> +#include <a.out.h> +#include <ldfcn.h> +#include "dlfcn.h" + +/* + * We simulate dlopen() et al. through a call to load. Because AIX has + * no call to find an exported symbol we read the loader section of the + * loaded module and build a list of exported symbols and their virtual + * address. + */ + +typedef struct { + char *name; /* the symbols's name */ + void *addr; /* its relocated virtual address */ +} Export, *ExportPtr; + +/* + * xlC uses the following structure to list its constructors and + * destructors. This is gleaned from the output of munch. + */ +typedef struct { + void (*init)(void); /* call static constructors */ + void (*term)(void); /* call static destructors */ +} Cdtor, *CdtorPtr; + +typedef void (*GccCDtorPtr)(void); + +/* + * The void * handle returned from dlopen is actually a ModulePtr. + */ +typedef struct Module { + struct Module *next; + char *name; /* module name for refcounting */ + int refCnt; /* the number of references */ + void *entry; /* entry point from load */ + struct dl_info *info; /* optional init/terminate functions */ + CdtorPtr cdtors; /* optional C++ constructors */ + GccCDtorPtr gcc_ctor; /* g++ constructors --jwe */ + GccCDtorPtr gcc_dtor; /* g++ destructors --jwe */ + int nExports; /* the number of exports found */ + ExportPtr exports; /* the array of exports */ +} Module, *ModulePtr; + +/* + * We keep a list of all loaded modules to be able to call the fini + * handlers and destructors at atexit() time. + */ +static ModulePtr modList; + +/* + * The last error from one of the dl* routines is kept in static + * variables here. Each error is returned only once to the caller. + */ +static char errbuf[BUFSIZ]; +static int errvalid; + +/* + * The `fixed' gcc header files on AIX 3.2.5 provide a prototype for + * strdup(). --jwe + */ +#ifndef HAVE_STRDUP +extern char *strdup(const char *); +#endif +static void caterr(char *); +static int readExports(ModulePtr); +static void terminate(void); +static void *findMain(void); + +void *dlopen(const char *path, int mode) +{ + ModulePtr mp; + static void *mainModule; + + /* + * Upon the first call register a terminate handler that will + * close all libraries. Also get a reference to the main module + * for use with loadbind. + */ + if (!mainModule) { + if ((mainModule = findMain()) == NULL) + return NULL; + atexit(terminate); + } + /* + * Scan the list of modules if we have the module already loaded. + */ + for (mp = modList; mp; mp = mp->next) + if (strcmp(mp->name, path) == 0) { + mp->refCnt++; + return mp; + } + if ((mp = (ModulePtr)calloc(1, sizeof(*mp))) == NULL) { + errvalid++; + strcpy(errbuf, "calloc: "); + strcat(errbuf, strerror(errno)); + return NULL; + } + if ((mp->name = strdup(path)) == NULL) { + errvalid++; + strcpy(errbuf, "strdup: "); + strcat(errbuf, strerror(errno)); + free(mp); + return NULL; + } + /* + * load should be declared load(const char *...). Thus we + * cast the path to a normal char *. Ugly. + */ + if ((mp->entry = (void *)load((char *)path, L_NOAUTODEFER, NULL)) == NULL) { + free(mp->name); + free(mp); + errvalid++; + strcpy(errbuf, "dlopen: "); + strcat(errbuf, path); + strcat(errbuf, ": "); + /* + * If AIX says the file is not executable, the error + * can be further described by querying the loader about + * the last error. + */ + if (errno == ENOEXEC) { + char *tmp[BUFSIZ/sizeof(char *)]; + if (loadquery(L_GETMESSAGES, tmp, sizeof(tmp)) == -1) + strcpy(errbuf, strerror(errno)); + else { + char **p; + for (p = tmp; *p; p++) + caterr(*p); + } + } else + strcat(errbuf, strerror(errno)); + return NULL; + } + mp->refCnt = 1; + mp->next = modList; + modList = mp; + if (loadbind(0, mainModule, mp->entry) == -1) { + dlclose(mp); + errvalid++; + strcpy(errbuf, "loadbind: "); + strcat(errbuf, strerror(errno)); + return NULL; + } + /* + * If the user wants global binding, loadbind against all other + * loaded modules. + */ + if (mode & RTLD_GLOBAL) { + ModulePtr mp1; + for (mp1 = mp->next; mp1; mp1 = mp1->next) + if (loadbind(0, mp1->entry, mp->entry) == -1) { + dlclose(mp); + errvalid++; + strcpy(errbuf, "loadbind: "); + strcat(errbuf, strerror(errno)); + return NULL; + } + } + if (readExports(mp) == -1) { + dlclose(mp); + return NULL; + } + /* + * If there is a dl_info structure, call the init function. + */ + if (mp->info = (struct dl_info *)dlsym(mp, "dl_info")) { + if (mp->info->init) + (*mp->info->init)(); + } else + errvalid = 0; + /* + * If the shared object was compiled using xlC we will need + * to call static constructors (and later on dlclose destructors). + */ + if (mp->cdtors = (CdtorPtr)dlsym(mp, "__cdtors")) { + CdtorPtr cp = mp->cdtors; + while (cp->init || cp->term) { + if (cp->init && cp->init != (void (*)(void))0xffffffff) + (*cp->init)(); + cp++; + } + /* + * If the shared object was compiled using g++, we will need + * to call global constructors using the _GLOBAL__DI function, + * and later, global destructors using the _GLOBAL_DD + * funciton. --jwe + */ + } else if (mp->gcc_ctor = (GccCDtorPtr)dlsym(mp, "_GLOBAL__DI")) { + (*mp->gcc_ctor)(); + mp->gcc_dtor = (GccCDtorPtr)dlsym(mp, "_GLOBAL__DD"); + } else + errvalid = 0; + return mp; +} + +/* + * Attempt to decipher an AIX loader error message and append it + * to our static error message buffer. + */ +static void caterr(char *s) +{ + char *p = s; + + while (*p >= '0' && *p <= '9') + p++; + switch(atoi(s)) { + case L_ERROR_TOOMANY: + strcat(errbuf, "to many errors"); + break; + case L_ERROR_NOLIB: + strcat(errbuf, "can't load library"); + strcat(errbuf, p); + break; + case L_ERROR_UNDEF: + strcat(errbuf, "can't find symbol"); + strcat(errbuf, p); + break; + case L_ERROR_RLDBAD: + strcat(errbuf, "bad RLD"); + strcat(errbuf, p); + break; + case L_ERROR_FORMAT: + strcat(errbuf, "bad exec format in"); + strcat(errbuf, p); + break; + case L_ERROR_ERRNO: + strcat(errbuf, strerror(atoi(++p))); + break; + default: + strcat(errbuf, s); + break; + } +} + +void *dlsym(void *handle, const char *symbol) +{ + ModulePtr mp = (ModulePtr)handle; + ExportPtr ep; + int i; + + /* + * Could speed up the search, but I assume that one assigns + * the result to function pointers anyways. + */ + for (ep = mp->exports, i = mp->nExports; i; i--, ep++) + if (strcmp(ep->name, symbol) == 0) + return ep->addr; + errvalid++; + strcpy(errbuf, "dlsym: undefined symbol "); + strcat(errbuf, symbol); + return NULL; +} + +char *dlerror(void) +{ + if (errvalid) { + errvalid = 0; + return errbuf; + } + return NULL; +} + +int dlclose(void *handle) +{ + ModulePtr mp = (ModulePtr)handle; + int result; + ModulePtr mp1; + + if (--mp->refCnt > 0) + return 0; + if (mp->info && mp->info->fini) + (*mp->info->fini)(); + if (mp->cdtors) { + CdtorPtr cp = mp->cdtors; + while (cp->init || cp->term) { + if (cp->term && cp->init != (void (*)(void))0xffffffff) + (*cp->term)(); + cp++; + } + /* + * If the function to handle global destructors for g++ + * exists, call it. --jwe + */ + } else if (mp->gcc_dtor) { + (*mp->gcc_dtor)(); + } + result = unload(mp->entry); + if (result == -1) { + errvalid++; + strcpy(errbuf, strerror(errno)); + } + if (mp->exports) { + ExportPtr ep; + int i; + for (ep = mp->exports, i = mp->nExports; i; i--, ep++) + if (ep->name) + free(ep->name); + free(mp->exports); + } + if (mp == modList) + modList = mp->next; + else { + for (mp1 = modList; mp1; mp1 = mp1->next) + if (mp1->next == mp) { + mp1->next = mp->next; + break; + } + } + free(mp->name); + free(mp); + return result; +} + +static void terminate(void) +{ + while (modList) + dlclose(modList); +} + +/* + * Build the export table from the XCOFF .loader section. + */ +static int readExports(ModulePtr mp) +{ + LDFILE *ldp = NULL; + SCNHDR sh, shdata; + LDHDR *lhp; + char *ldbuf; + LDSYM *ls; + int i; + ExportPtr ep; + + if ((ldp = ldopen(mp->name, ldp)) == NULL) { + struct ld_info *lp; + char *buf; + int size = 4*1024; + if (errno != ENOENT) { + errvalid++; + strcpy(errbuf, "readExports: "); + strcat(errbuf, strerror(errno)); + return -1; + } + /* + * The module might be loaded due to the LIBPATH + * environment variable. Search for the loaded + * module using L_GETINFO. + */ + if ((buf = malloc(size)) == NULL) { + errvalid++; + strcpy(errbuf, "readExports: "); + strcat(errbuf, strerror(errno)); + return -1; + } + while ((i = loadquery(L_GETINFO, buf, size)) == -1 && errno == ENOMEM) { + free(buf); + size += 4*1024; + if ((buf = malloc(size)) == NULL) { + errvalid++; + strcpy(errbuf, "readExports: "); + strcat(errbuf, strerror(errno)); + return -1; + } + } + if (i == -1) { + errvalid++; + strcpy(errbuf, "readExports: "); + strcat(errbuf, strerror(errno)); + free(buf); + return -1; + } + /* + * Traverse the list of loaded modules. The entry point + * returned by load() does actually point to the data + * segment origin. + */ + lp = (struct ld_info *)buf; + while (lp) { + if (lp->ldinfo_dataorg == mp->entry) { + ldp = ldopen(lp->ldinfo_filename, ldp); + break; + } + if (lp->ldinfo_next == 0) + lp = NULL; + else + lp = (struct ld_info *)((char *)lp + lp->ldinfo_next); + } + free(buf); + if (!ldp) { + errvalid++; + strcpy(errbuf, "readExports: "); + strcat(errbuf, strerror(errno)); + return -1; + } + } + if (TYPE(ldp) != U802TOCMAGIC) { + errvalid++; + strcpy(errbuf, "readExports: bad magic"); + while(ldclose(ldp) == FAILURE) + ; + return -1; + } + /* + * Get the padding for the data section. This is needed for + * AIX 4.1 compilers. This is used when building the final + * function pointer to the exported symbol. + */ + if (ldnshread(ldp, _DATA, &shdata) != SUCCESS) { + errvalid++; + strcpy(errbuf, "readExports: cannot read data section header"); + while(ldclose(ldp) == FAILURE) + ; + return -1; + } + if (ldnshread(ldp, _LOADER, &sh) != SUCCESS) { + errvalid++; + strcpy(errbuf, "readExports: cannot read loader section header"); + while(ldclose(ldp) == FAILURE) + ; + return -1; + } + /* + * We read the complete loader section in one chunk, this makes + * finding long symbol names residing in the string table easier. + */ + if ((ldbuf = (char *)malloc(sh.s_size)) == NULL) { + errvalid++; + strcpy(errbuf, "readExports: "); + strcat(errbuf, strerror(errno)); + while(ldclose(ldp) == FAILURE) + ; + return -1; + } + if (FSEEK(ldp, sh.s_scnptr, BEGINNING) != OKFSEEK) { + errvalid++; + strcpy(errbuf, "readExports: cannot seek to loader section"); + free(ldbuf); + while(ldclose(ldp) == FAILURE) + ; + return -1; + } + if (FREAD(ldbuf, sh.s_size, 1, ldp) != 1) { + errvalid++; + strcpy(errbuf, "readExports: cannot read loader section"); + free(ldbuf); + while(ldclose(ldp) == FAILURE) + ; + return -1; + } + lhp = (LDHDR *)ldbuf; + ls = (LDSYM *)(ldbuf+LDHDRSZ); + /* + * Count the number of exports to include in our export table. + */ + for (i = lhp->l_nsyms; i; i--, ls++) { + if (!LDR_EXPORT(*ls)) + continue; + mp->nExports++; + } + if ((mp->exports = (ExportPtr)calloc(mp->nExports, sizeof(*mp->exports))) == NULL) { + errvalid++; + strcpy(errbuf, "readExports: "); + strcat(errbuf, strerror(errno)); + free(ldbuf); + while(ldclose(ldp) == FAILURE) + ; + return -1; + } + /* + * Fill in the export table. All entries are relative to + * the entry point we got from load. + */ + ep = mp->exports; + ls = (LDSYM *)(ldbuf+LDHDRSZ); + for (i = lhp->l_nsyms; i; i--, ls++) { + char *symname; + char tmpsym[SYMNMLEN+1]; + if (!LDR_EXPORT(*ls)) + continue; + if (ls->l_zeroes == 0) + symname = ls->l_offset+lhp->l_stoff+ldbuf; + else { + /* + * The l_name member is not zero terminated, we + * must copy the first SYMNMLEN chars and make + * sure we have a zero byte at the end. + */ + strncpy(tmpsym, ls->l_name, SYMNMLEN); + tmpsym[SYMNMLEN] = '\0'; + symname = tmpsym; + } + ep->name = strdup(symname); + ep->addr = (void *)((unsigned long)mp->entry + + ls->l_value - shdata.s_vaddr); + ep++; + } + free(ldbuf); + while(ldclose(ldp) == FAILURE) + ; + return 0; +} + +/* + * Find the main modules entry point. This is used as export pointer + * for loadbind() to be able to resolve references to the main part. + */ +static void * findMain(void) +{ + struct ld_info *lp; + char *buf; + int size = 4*1024; + int i; + void *ret; + + if ((buf = malloc(size)) == NULL) { + errvalid++; + strcpy(errbuf, "findMain: "); + strcat(errbuf, strerror(errno)); + return NULL; + } + while ((i = loadquery(L_GETINFO, buf, size)) == -1 && errno == ENOMEM) { + free(buf); + size += 4*1024; + if ((buf = malloc(size)) == NULL) { + errvalid++; + strcpy(errbuf, "findMain: "); + strcat(errbuf, strerror(errno)); + return NULL; + } + } + if (i == -1) { + errvalid++; + strcpy(errbuf, "findMain: "); + strcat(errbuf, strerror(errno)); + free(buf); + return NULL; + } + /* + * The first entry is the main module. The entry point + * returned by load() does actually point to the data + * segment origin. + */ + lp = (struct ld_info *)buf; + ret = lp->ldinfo_dataorg; + free(buf); + return ret; +} |