/* Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /* * dso.c -- DSO system function emulation for AIX * * This is *only* intended for AIX < 4.3. */ /* * Based on libdl (dlfcn.c/dlfcn.h) which is * Copyright (c) 1992,1993,1995,1996,1997,1988 * Jens-Uwe Mager, Helios Software GmbH, Hannover, Germany. * * Not derived from licensed software. * * Permission is granted to freely use, copy, modify, and redistribute * this software, provided that the author is not construed to be liable * for any results of using the software, alterations are clearly marked * as such, and this notice is not modified. * * Changes marked with `--jwe' were made on April 7 1996 by * John W. Eaton to support g++ * * Bundled, stripped and adjusted on April 1998 as one single source file * for inclusion into the Apache HTTP server by * Ralf S. Engelschall * * Added to APR by David Reid April 2000 */ #include #include #include #include #include #include #include #include "fspr_arch_dso.h" #include "fspr_portable.h" #if APR_HAS_DSO #undef FREAD #undef FWRITE #include /* * AIX 4.3 does remove some useful definitions from ldfcn.h. Define * these here to compensate for that lossage. */ #ifndef BEGINNING #define BEGINNING SEEK_SET #endif #ifndef FSEEK #define FSEEK(ldptr,o,p) fseek(IOPTR(ldptr),(p==BEGINNING)?(OFFSET(ldptr) +o):o,p) #endif #ifndef FREAD #define FREAD(p,s,n,ldptr) fread(p,s,n,IOPTR(ldptr)) #endif /* * Mode flags for the dlopen routine. */ #undef RTLD_LAZY #define RTLD_LAZY 1 /* lazy function call binding */ #undef RTLD_NOW #define RTLD_NOW 2 /* immediate function call binding */ #undef RTLD_GLOBAL #define RTLD_GLOBAL 0x100 /* allow symbols to be global */ /* * To be able to initialize, a library may provide a dl_info structure * that contains functions to be called to initialize and terminate. */ struct dl_info { void (*init) (void); void (*fini) (void); }; /* APR functions... * * As the AIX functions have been declared in the header file we just * add the basic "wrappers" here. */ APR_DECLARE(fspr_status_t) fspr_os_dso_handle_put(fspr_dso_handle_t **aprdso, fspr_os_dso_handle_t osdso, fspr_pool_t *pool) { *aprdso = fspr_pcalloc(pool, sizeof **aprdso); (*aprdso)->handle = osdso; (*aprdso)->pool = pool; return APR_SUCCESS; } APR_DECLARE(fspr_status_t) fspr_os_dso_handle_get(fspr_os_dso_handle_t *osdso, fspr_dso_handle_t *aprdso) { *osdso = aprdso->handle; return APR_SUCCESS; } static fspr_status_t dso_cleanup(void *thedso) { fspr_dso_handle_t *dso = thedso; if (dso->handle != NULL && dlclose(dso->handle) != 0) return APR_EINIT; dso->handle = NULL; return APR_SUCCESS; } APR_DECLARE(fspr_status_t) fspr_dso_load(fspr_dso_handle_t **res_handle, const char *path, fspr_pool_t *ctx) { void *os_handle = dlopen((char *)path, RTLD_NOW | RTLD_GLOBAL); *res_handle = fspr_pcalloc(ctx, sizeof(*res_handle)); if(os_handle == NULL) { (*res_handle)->errormsg = dlerror(); return APR_EDSOOPEN; } (*res_handle)->handle = (void*)os_handle; (*res_handle)->pool = ctx; (*res_handle)->errormsg = NULL; fspr_pool_cleanup_register(ctx, *res_handle, dso_cleanup, fspr_pool_cleanup_null); return APR_SUCCESS; } APR_DECLARE(fspr_status_t) fspr_dso_unload(fspr_dso_handle_t *handle) { return fspr_pool_cleanup_run(handle->pool, handle, dso_cleanup); } APR_DECLARE(fspr_status_t) fspr_dso_sym(fspr_dso_handle_sym_t *ressym, fspr_dso_handle_t *handle, const char *symname) { void *retval = dlsym(handle->handle, symname); if (retval == NULL) { handle->errormsg = dlerror(); return APR_ESYMNOTFOUND; } *ressym = retval; return APR_SUCCESS; } APR_DECLARE(const char *) fspr_dso_error(fspr_dso_handle_t *dso, char *buffer, fspr_size_t buflen) { if (dso->errormsg) { fspr_cpystrn(buffer, dso->errormsg, buflen); return dso->errormsg; } return "No Error"; } /* * 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 */ extern char *strdup(const char *); static void caterr(char *); static int readExports(ModulePtr); static void terminate(void); static void *findMain(void); void *dlopen(const char *path, int mode) { register 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 *) loadAndInit((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) { register 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) { register 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) { register ModulePtr mp = (ModulePtr) handle; register ExportPtr ep; register 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; } const char *dlerror(void) { if (errvalid) { errvalid = 0; return errbuf; } return NULL; } int dlclose(void *handle) { register ModulePtr mp = (ModulePtr) handle; int result; register 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) { register ExportPtr ep; register 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; struct ld_info *lp; char *buf; int size = 4 * 1024; void *dataorg; /* * 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 TOC * entry contained in the data segment. */ lp = (struct ld_info *) buf; while (lp) { if ((unsigned long) mp->entry >= (unsigned long) lp->ldinfo_dataorg && (unsigned long) mp->entry < (unsigned long) lp->ldinfo_dataorg + lp->ldinfo_datasize) { dataorg = lp->ldinfo_dataorg; 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 beginning of the data origin. */ 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) dataorg + ls->l_value - shdata.s_vaddr); ep++; } free(ldbuf); while (ldclose(ldp) == FAILURE); return 0; } /* * Find the main modules data origin. 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 data segment * starts with the TOC entries for all exports, so the * data segment origin works as argument for loadbind. */ lp = (struct ld_info *) buf; ret = lp->ldinfo_dataorg; free(buf); return ret; } #endif