From: Chuck Lever Date: Fri, 28 Sep 2007 20:36:30 +0000 (-0400) Subject: mount.nfs: add new string tokenizer facility X-Git-Tag: nfs-utils-1-1-1~35 X-Git-Url: https://git.decadent.org.uk/gitweb/?p=nfs-utils.git;a=commitdiff_plain;h=af5939d15a41b337cc499a04fe4001a5cd51fdce mount.nfs: add new string tokenizer facility To quote the strtok(3) man page: "Avoid using these functions." OK. We've created our own. The main reason for this is that strtok(3) doesn't handle quoted delimiters at all. We need to handle this: context="foo,bar" where 'context' is a single mount option that sets a token string that possibly uses the same delimiter that the mount command uses to separate options (that is, a comma). Signed-off-by: Chuck Lever Signed-off-by: Neil Brown --- diff --git a/utils/mount/Makefile.am b/utils/mount/Makefile.am index 23e7ae9..cfee756 100644 --- a/utils/mount/Makefile.am +++ b/utils/mount/Makefile.am @@ -9,10 +9,10 @@ man5_MANS = nfs.man sbin_PROGRAMS = mount.nfs EXTRA_DIST = nfsmount.x $(man8_MANS) $(man5_MANS) -mount_nfs_SOURCES = mount.c error.c network.c fstab.c \ +mount_nfs_SOURCES = mount.c error.c network.c fstab.c token.c \ nfsmount.c nfs4mount.c stropts.c\ nfsumount.c \ - mount_constants.h error.h network.h fstab.h \ + mount_constants.h error.h network.h fstab.h token.h \ nfs4_mount.h nfs_mount4.h stropts.h mount_nfs_LDADD = ../../support/nfs/libnfs.a \ diff --git a/utils/mount/token.c b/utils/mount/token.c new file mode 100644 index 0000000..5ef9604 --- /dev/null +++ b/utils/mount/token.c @@ -0,0 +1,157 @@ +/* + * token.c -- tokenize strings, a la strtok(3) + * + * Copyright (C) 2007 Oracle. All rights reserved. + * Copyright (C) 2007 Chuck Lever + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + * + */ + +/* + * We've constructed a simple string tokenizer that is better than + * strtok(3) in several ways: + * + * 1. It doesn't interfere with ongoing tokenizations using strtok(3). + * 2. It's re-entrant so we can nest tokenizations, if needed. + * 3. It can handle double-quoted delimiters (needed for 'context="sd,fslj"'). + * 4. It doesn't alter the string we're tokenizing, so it can work + * on write-protected strings as well as writable strings. + */ + + +#include +#include +#include +#include +#include +#include + +#include "token.h" + + +struct tokenizer_state { + char *pos; + char delimiter; + int error; +}; + +static void find_next_nondelimiter(struct tokenizer_state *tstate) +{ + while (*tstate->pos != '\0' && *tstate->pos == tstate->delimiter) + tstate->pos++; +} + +static size_t find_next_delimiter(struct tokenizer_state *tstate) +{ + size_t len = 0; + int quote_seen = 0; + + while (*tstate->pos != '\0') { + if (*tstate->pos == '"') + quote_seen ^= 1; + + if (!quote_seen && *tstate->pos == tstate->delimiter) + break; + + len++; + tstate->pos++; + } + + /* did the string terminate before the close quote? */ + if (quote_seen) { + tstate->error = EINVAL; + return 0; + } + + return len; +} + +/** + * next_token - find the next token in a string and return it + * @tstate: pointer to tokenizer context object + * + * Returns the next token found in the current string. + * Returns NULL if there are no more tokens in the string, + * or if an error occurs. + * + * Side effect: tstate is updated + */ +char *next_token(struct tokenizer_state *tstate) +{ + char *token; + size_t len; + + if (!tstate || !tstate->pos || tstate->error) + return NULL; + + find_next_nondelimiter(tstate); + if (*tstate->pos == '\0') + goto fail; + token = tstate->pos; + + len = find_next_delimiter(tstate); + if (len) { + token = strndup(token, len); + if (token) + return token; + tstate->error = ENOMEM; + } + +fail: + tstate->pos = NULL; + return NULL; /* no tokens found in this string */ +} + +/** + * init_tokenizer - return an initialized tokenizer context object + * @string: pointer to C string + * @delimiter: single character that delimits tokens in @string + * + * Returns an initialized tokenizer context object + */ +struct tokenizer_state *init_tokenizer(char *string, char delimiter) +{ + struct tokenizer_state *tstate; + + tstate = malloc(sizeof(*tstate)); + if (tstate) { + tstate->pos = string; + tstate->delimiter = delimiter; + tstate->error = 0; + } + return tstate; +} + +/** + * tokenizer_error - digs error value out of tokenizer context + * @tstate: pointer to tokenizer context object + * + */ +int tokenizer_error(struct tokenizer_state *tstate) +{ + return tstate ? tstate->error : 0; +} + +/** + * end_tokenizer - free a tokenizer context object + * @tstate: pointer to tokenizer context object + * + */ +void end_tokenizer(struct tokenizer_state *tstate) +{ + free(tstate); +} diff --git a/utils/mount/token.h b/utils/mount/token.h new file mode 100644 index 0000000..47762dc --- /dev/null +++ b/utils/mount/token.h @@ -0,0 +1,29 @@ +/* + * token.h -- tokenize strings, a la strtok(3) + * + * Copyright (C) 2007 Oracle. All rights reserved. + * Copyright (C) 2007 Chuck Lever + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + * + */ + +struct tokenizer_state; + +char *next_token(struct tokenizer_state *); +struct tokenizer_state *init_tokenizer(char *, char); +int tokenizer_error(struct tokenizer_state *); +void end_tokenizer(struct tokenizer_state *);