/* * Copyright (c) 1997-2006 Erez Zadok * Copyright (c) 1990 Jan-Simon Pendry * Copyright (c) 1990 Imperial College of Science, Technology & Medicine * Copyright (c) 1990 The Regents of the University of California. * All rights reserved. * * This code is derived from software contributed to Berkeley by * Jan-Simon Pendry at Imperial College, London. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgment: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * * File: am-utils/amd/readdir.c * */ #ifdef HAVE_CONFIG_H # include #endif /* HAVE_CONFIG_H */ #include #include /**************************************************************************** *** MACROS *** ****************************************************************************/ #define DOT_DOT_COOKIE (u_int) 1 #define MAX_CHAIN 2048 /**************************************************************************** *** FORWARD DEFINITIONS *** ****************************************************************************/ static int key_already_in_chain(char *keyname, const nfsentry *chain); static nfsentry *make_entry_chain(am_node *mp, const nfsentry *current_chain, int fully_browsable); static int amfs_readdir_browsable(am_node *mp, nfscookie cookie, nfsdirlist *dp, nfsentry *ep, u_int count, int fully_browsable); /**************************************************************************** *** FUNCTIONS *** ****************************************************************************/ /* * Was: NEW_TOPLVL_READDIR * Search a chain for an entry with some name. * -Erez Zadok */ static int key_already_in_chain(char *keyname, const nfsentry *chain) { const nfsentry *tmpchain = chain; while (tmpchain) { if (keyname && tmpchain->ne_name && STREQ(keyname, tmpchain->ne_name)) return 1; tmpchain = tmpchain->ne_nextentry; } return 0; } /* * Create a chain of entries which are not linked. * -Erez Zadok */ static nfsentry * make_entry_chain(am_node *mp, const nfsentry *current_chain, int fully_browsable) { static u_int last_cookie = (u_int) 2; /* monotonically increasing */ static nfsentry chain[MAX_CHAIN]; static int max_entries = MAX_CHAIN; char *key; int num_entries = 0, i; u_int preflen = 0; nfsentry *retval = (nfsentry *) NULL; mntfs *mf; mnt_map *mmp; if (!mp) { plog(XLOG_DEBUG, "make_entry_chain: mp is (NULL)"); return retval; } mf = mp->am_mnt; if (!mf) { plog(XLOG_DEBUG, "make_entry_chain: mp->am_mnt is (NULL)"); return retval; } mmp = (mnt_map *) mf->mf_private; if (!mmp) { plog(XLOG_DEBUG, "make_entry_chain: mp->am_mnt->mf_private is (NULL)"); return retval; } if (mp->am_pref) preflen = strlen(mp->am_pref); /* iterate over keys */ for (i = 0; i < NKVHASH; i++) { kv *k; for (k = mmp->kvhash[i]; k ; k = k->next) { /* * Skip unwanted entries which are either not real entries or * very difficult to interpret (wildcards...) This test needs * lots of improvement. Any takers? */ key = k->key; if (!key) continue; /* Skip '/defaults' */ if (STREQ(key, "/defaults")) continue; /* Skip '*' */ if (!fully_browsable && strchr(key, '*')) continue; /* * If the map has a prefix-string then check if the key starts with * this string, and if it does, skip over this prefix. If it has a * prefix and it doesn't match the start of the key, skip it. */ if (preflen) { if (preflen > strlen(key)) continue; if (!NSTREQ(key, mp->am_pref, preflen)) continue; key += preflen; } /* no more '/' are allowed, unless browsable_dirs=full was used */ if (!fully_browsable && strchr(key, '/')) continue; /* no duplicates allowed */ if (key_already_in_chain(key, current_chain)) continue; /* fill in a cell and link the entry */ if (num_entries >= max_entries) { /* out of space */ plog(XLOG_DEBUG, "make_entry_chain: no more space in chain"); if (num_entries > 0) { chain[num_entries - 1].ne_nextentry = 0; retval = &chain[0]; } return retval; } /* we have space. put entry in next cell */ ++last_cookie; chain[num_entries].ne_fileid = (u_int) last_cookie; *(u_int *) chain[num_entries].ne_cookie = (u_int) last_cookie; chain[num_entries].ne_name = key; if (num_entries < max_entries - 1) { /* link to next one */ chain[num_entries].ne_nextentry = &chain[num_entries + 1]; } ++num_entries; } /* end of "while (k)" */ } /* end of "for (i ... NKVHASH ..." */ /* terminate chain */ if (num_entries > 0) { chain[num_entries - 1].ne_nextentry = 0; retval = &chain[0]; } return retval; } /* This one is called only if map is browsable */ static int amfs_readdir_browsable(am_node *mp, nfscookie cookie, nfsdirlist *dp, nfsentry *ep, u_int count, int fully_browsable) { u_int gen = *(u_int *) cookie; int chain_length, i; static nfsentry *te, *te_next; static int j; dp->dl_eof = FALSE; /* assume readdir not done */ if (amuDebug(D_READDIR)) plog(XLOG_DEBUG, "amfs_readdir_browsable gen=%u, count=%d", gen, count); if (gen == 0) { /* * In the default instance (which is used to start a search) we return * "." and "..". * * This assumes that the count is big enough to allow both "." and ".." * to be returned in a single packet. If it isn't (which would be * fairly unbelievable) then tough. */ dlog("amfs_readdir_browsable: default search"); /* * Check for enough room. This is extremely approximate but is more * than enough space. Really need 2 times: * 4byte fileid * 4byte cookie * 4byte name length * 4byte name * plus the dirlist structure */ if (count < (2 * (2 * (sizeof(*ep) + sizeof("..") + 4) + sizeof(*dp)))) return EINVAL; /* * compute # of entries to send in this chain. * heuristics: 128 bytes per entry. * This is too much probably, but it seems to work better because * of the re-entrant nature of nfs_readdir, and esp. on systems * like OpenBSD 2.2. */ chain_length = count / 128; /* reset static state counters */ te = te_next = NULL; dp->dl_entries = ep; /* construct "." */ ep[0].ne_fileid = mp->am_gen; ep[0].ne_name = "."; ep[0].ne_nextentry = &ep[1]; *(u_int *) ep[0].ne_cookie = 0; /* construct ".." */ if (mp->am_parent) ep[1].ne_fileid = mp->am_parent->am_gen; else ep[1].ne_fileid = mp->am_gen; ep[1].ne_name = ".."; ep[1].ne_nextentry = 0; *(u_int *) ep[1].ne_cookie = DOT_DOT_COOKIE; /* * If map is browsable, call a function make_entry_chain() to construct * a linked list of unmounted keys, and return it. Then link the chain * to the regular list. Get the chain only once, but return * chunks of it each time. */ te = make_entry_chain(mp, dp->dl_entries, fully_browsable); if (!te) return 0; if (amuDebug(D_READDIR)) { nfsentry *ne; for (j = 0, ne = te; ne; ne = ne->ne_nextentry) plog(XLOG_DEBUG, "gen1 key %4d \"%s\"", j++, ne->ne_name); } /* return only "chain_length" entries */ te_next = te; for (i=1; ine_nextentry; if (!te_next) break; } if (te_next) { nfsentry *te_saved = te_next->ne_nextentry; te_next->ne_nextentry = NULL; /* terminate "te" chain */ te_next = te_saved; /* save rest of "te" for next iteration */ dp->dl_eof = FALSE; /* tell readdir there's more */ } else { dp->dl_eof = TRUE; /* tell readdir that's it */ } ep[1].ne_nextentry = te; /* append this chunk of "te" chain */ if (amuDebug(D_READDIR)) { nfsentry *ne; for (j = 0, ne = te; ne; ne = ne->ne_nextentry) plog(XLOG_DEBUG, "gen2 key %4d \"%s\"", j++, ne->ne_name); for (j = 0, ne = ep; ne; ne = ne->ne_nextentry) plog(XLOG_DEBUG, "gen2+ key %4d \"%s\" fi=%d ck=%d", j++, ne->ne_name, ne->ne_fileid, *(u_int *)ne->ne_cookie); plog(XLOG_DEBUG, "EOF is %d", dp->dl_eof); } return 0; } /* end of "if (gen == 0)" statement */ dlog("amfs_readdir_browsable: real child"); if (gen == DOT_DOT_COOKIE) { dlog("amfs_readdir_browsable: End of readdir in %s", mp->am_path); dp->dl_eof = TRUE; dp->dl_entries = 0; return 0; } /* * If browsable directories, then continue serving readdir() with another * chunk of entries, starting from where we left off (when gen was equal * to 0). Once again, assume last chunk served to readdir. */ dp->dl_eof = TRUE; dp->dl_entries = ep; te = te_next; /* reset 'te' from last saved te_next */ if (!te) { /* another indicator of end of readdir */ dp->dl_entries = 0; return 0; } /* * compute # of entries to send in this chain. * heuristics: 128 bytes per entry. */ chain_length = count / 128; /* return only "chain_length" entries */ for (i = 1; i < chain_length; ++i) { te_next = te_next->ne_nextentry; if (!te_next) break; } if (te_next) { nfsentry *te_saved = te_next->ne_nextentry; te_next->ne_nextentry = NULL; /* terminate "te" chain */ te_next = te_saved; /* save rest of "te" for next iteration */ dp->dl_eof = FALSE; /* tell readdir there's more */ } ep = te; /* send next chunk of "te" chain */ dp->dl_entries = ep; if (amuDebug(D_READDIR)) { nfsentry *ne; plog(XLOG_DEBUG, "dl_entries=%p, te_next=%p, dl_eof=%d", dp->dl_entries, te_next, dp->dl_eof); for (ne = te; ne; ne = ne->ne_nextentry) plog(XLOG_DEBUG, "gen3 key %4d \"%s\"", j++, ne->ne_name); } return 0; } /* * This readdir function which call a special version of it that allows * browsing if browsable_dirs=yes was set on the map. */ int amfs_generic_readdir(am_node *mp, nfscookie cookie, nfsdirlist *dp, nfsentry *ep, u_int count) { u_int gen = *(u_int *) cookie; am_node *xp; mntent_t mnt; dp->dl_eof = FALSE; /* assume readdir not done */ /* check if map is browsable */ if (mp->am_mnt && mp->am_mnt->mf_mopts) { mnt.mnt_opts = mp->am_mnt->mf_mopts; if (amu_hasmntopt(&mnt, "fullybrowsable")) return amfs_readdir_browsable(mp, cookie, dp, ep, count, TRUE); if (amu_hasmntopt(&mnt, "browsable")) return amfs_readdir_browsable(mp, cookie, dp, ep, count, FALSE); } /* when gen is 0, we start reading from the beginning of the directory */ if (gen == 0) { /* * In the default instance (which is used to start a search) we return * "." and "..". * * This assumes that the count is big enough to allow both "." and ".." * to be returned in a single packet. If it isn't (which would be * fairly unbelievable) then tough. */ dlog("amfs_generic_readdir: default search"); /* * Check for enough room. This is extremely approximate but is more * than enough space. Really need 2 times: * 4byte fileid * 4byte cookie * 4byte name length * 4byte name * plus the dirlist structure */ if (count < (2 * (2 * (sizeof(*ep) + sizeof("..") + 4) + sizeof(*dp)))) return EINVAL; xp = next_nonerror_node(mp->am_child); dp->dl_entries = ep; /* construct "." */ ep[0].ne_fileid = mp->am_gen; ep[0].ne_name = "."; ep[0].ne_nextentry = &ep[1]; *(u_int *) ep[0].ne_cookie = 0; /* construct ".." */ if (mp->am_parent) ep[1].ne_fileid = mp->am_parent->am_gen; else ep[1].ne_fileid = mp->am_gen; ep[1].ne_name = ".."; ep[1].ne_nextentry = 0; *(u_int *) ep[1].ne_cookie = (xp ? xp->am_gen : DOT_DOT_COOKIE); if (!xp) dp->dl_eof = TRUE; /* by default assume readdir done */ if (amuDebug(D_READDIR)) { nfsentry *ne; int j; for (j = 0, ne = ep; ne; ne = ne->ne_nextentry) plog(XLOG_DEBUG, "gen1 key %4d \"%s\" fi=%d ck=%d", j++, ne->ne_name, ne->ne_fileid, *(u_int *)ne->ne_cookie); } return 0; } dlog("amfs_generic_readdir: real child"); if (gen == DOT_DOT_COOKIE) { dlog("amfs_generic_readdir: End of readdir in %s", mp->am_path); dp->dl_eof = TRUE; dp->dl_entries = 0; if (amuDebug(D_READDIR)) plog(XLOG_DEBUG, "end of readdir eof=TRUE, dl_entries=0\n"); return 0; } /* non-browsable directories code */ xp = mp->am_child; while (xp && xp->am_gen != gen) xp = xp->am_osib; if (xp) { int nbytes = count / 2; /* conservative */ int todo = MAX_READDIR_ENTRIES; dp->dl_entries = ep; do { am_node *xp_next = next_nonerror_node(xp->am_osib); if (xp_next) { *(u_int *) ep->ne_cookie = xp_next->am_gen; } else { *(u_int *) ep->ne_cookie = DOT_DOT_COOKIE; dp->dl_eof = TRUE; } ep->ne_fileid = xp->am_gen; ep->ne_name = xp->am_name; nbytes -= sizeof(*ep) + 1; if (xp->am_name) nbytes -= strlen(xp->am_name); xp = xp_next; if (nbytes > 0 && !dp->dl_eof && todo > 1) { ep->ne_nextentry = ep + 1; ep++; --todo; } else { todo = 0; } } while (todo > 0); ep->ne_nextentry = 0; if (amuDebug(D_READDIR)) { nfsentry *ne; int j; for (j=0,ne=ep; ne; ne=ne->ne_nextentry) plog(XLOG_DEBUG, "gen2 key %4d \"%s\" fi=%d ck=%d", j++, ne->ne_name, ne->ne_fileid, *(u_int *)ne->ne_cookie); } return 0; } return ESTALE; }