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Diffstat (limited to 'contrib/amd/amd/readdir.c')
-rw-r--r-- | contrib/amd/amd/readdir.c | 498 |
1 files changed, 498 insertions, 0 deletions
diff --git a/contrib/amd/amd/readdir.c b/contrib/amd/amd/readdir.c new file mode 100644 index 0000000..d025c91 --- /dev/null +++ b/contrib/amd/amd/readdir.c @@ -0,0 +1,498 @@ +/* + * 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 <config.h> +#endif /* HAVE_CONFIG_H */ +#include <am_defs.h> +#include <amd.h> + + +/**************************************************************************** + *** 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 <ezk@cs.columbia.edu> + */ +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 <ezk@cs.columbia.edu> + */ +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; 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 */ + } 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; +} |