From 8f6b0c1b360f2fea3f7f6563808513cbdd51df80 Mon Sep 17 00:00:00 2001 From: Tavian Barnes Date: Wed, 10 Apr 2024 10:10:51 -0400 Subject: Implement -context Closes: https://github.com/tavianator/bfs/issues/27 --- src/eval.c | 43 +++++++++++++++-------- src/eval.h | 1 + src/parse.c | 114 +++++++++++++++++++++++++++++++++++------------------------- 3 files changed, 96 insertions(+), 62 deletions(-) (limited to 'src') diff --git a/src/eval.c b/src/eval.c index 2f06858..d0112c2 100644 --- a/src/eval.c +++ b/src/eval.c @@ -145,6 +145,20 @@ bool bfs_expr_cmp(const struct bfs_expr *expr, long long n) { return false; } +/** Common code for fnmatch() tests. */ +static bool eval_fnmatch(const struct bfs_expr *expr, const char *str) { + if (expr->literal) { +#ifdef FNM_CASEFOLD + if (expr->fnm_flags & FNM_CASEFOLD) { + return strcasecmp(expr->pattern, str) == 0; + } +#endif + return strcmp(expr->pattern, str) == 0; + } else { + return fnmatch(expr->pattern, str, expr->fnm_flags) == 0; + } +} + /** * -true test. */ @@ -193,6 +207,21 @@ bool eval_capable(const struct bfs_expr *expr, struct bfs_eval *state) { } } +/** + * -context test. + */ +bool eval_context(const struct bfs_expr *expr, struct bfs_eval *state) { + char *con = bfs_getfilecon(state->ftwbuf); + if (!con) { + eval_report_error(state); + return false; + } + + bool ret = eval_fnmatch(expr, con); + bfs_freecon(con); + return ret; +} + /** * Get the given timespec field out of a stat buffer. */ @@ -546,20 +575,6 @@ bool eval_links(const struct bfs_expr *expr, struct bfs_eval *state) { return bfs_expr_cmp(expr, statbuf->nlink); } -/** Common code for fnmatch() tests. */ -static bool eval_fnmatch(const struct bfs_expr *expr, const char *str) { - if (expr->literal) { -#ifdef FNM_CASEFOLD - if (expr->fnm_flags & FNM_CASEFOLD) { - return strcasecmp(expr->pattern, str) == 0; - } -#endif - return strcmp(expr->pattern, str) == 0; - } else { - return fnmatch(expr->pattern, str, expr->fnm_flags) == 0; - } -} - /** * -i?lname test. */ diff --git a/src/eval.h b/src/eval.h index f7f6c77..ae43628 100644 --- a/src/eval.h +++ b/src/eval.h @@ -49,6 +49,7 @@ bool eval_false(const struct bfs_expr *expr, struct bfs_eval *state); bool eval_access(const struct bfs_expr *expr, struct bfs_eval *state); bool eval_acl(const struct bfs_expr *expr, struct bfs_eval *state); bool eval_capable(const struct bfs_expr *expr, struct bfs_eval *state); +bool eval_context(const struct bfs_expr *expr, struct bfs_eval *state); bool eval_perm(const struct bfs_expr *expr, struct bfs_eval *state); bool eval_xattr(const struct bfs_expr *expr, struct bfs_eval *state); bool eval_xattrname(const struct bfs_expr *expr, struct bfs_eval *state); diff --git a/src/parse.c b/src/parse.c index 38ebf3f..a3e32fe 100644 --- a/src/parse.c +++ b/src/parse.c @@ -1075,6 +1075,67 @@ static struct bfs_expr *parse_color(struct bfs_parser *parser, int color, int ar return expr; } +/** + * Common code for fnmatch() tests. + */ +static struct bfs_expr *parse_fnmatch(const struct bfs_parser *parser, struct bfs_expr *expr, bool casefold) { + if (!expr) { + return NULL; + } + + expr->pattern = expr->argv[1]; + + if (casefold) { +#ifdef FNM_CASEFOLD + expr->fnm_flags = FNM_CASEFOLD; +#else + parse_expr_error(parser, expr, "Missing platform support.\n"); + return NULL; +#endif + } else { + expr->fnm_flags = 0; + } + + // POSIX says, about fnmatch(): + // + // If pattern ends with an unescaped , fnmatch() shall + // return a non-zero value (indicating either no match or an error). + // + // But not all implementations obey this, so check for it ourselves. + size_t i, len = strlen(expr->pattern); + for (i = 0; i < len; ++i) { + if (expr->pattern[len - i - 1] != '\\') { + break; + } + } + if (i % 2 != 0) { + parse_expr_warning(parser, expr, "Unescaped trailing backslash.\n\n"); + expr->eval_fn = eval_false; + return expr; + } + + // strcmp() can be much faster than fnmatch() since it doesn't have to + // parse the pattern, so special-case patterns with no wildcards. + // + // https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_13_01 + expr->literal = strcspn(expr->pattern, "?*\\[") == len; + + return expr; +} + +/** + * Parse -context. + */ +static struct bfs_expr *parse_context(struct bfs_parser *parser, int flag, int arg2) { +#if BFS_CAN_CHECK_CONTEXT + struct bfs_expr *expr = parse_unary_test(parser, eval_context); + return parse_fnmatch(parser, expr, false); +#else + parse_error(parser, "Missing platform support.\n"); + return NULL; +#endif +} + /** * Parse -{false,true}. */ @@ -1631,54 +1692,6 @@ static struct bfs_expr *parse_mount(struct bfs_parser *parser, int arg1, int arg return expr; } -/** - * Common code for fnmatch() tests. - */ -static struct bfs_expr *parse_fnmatch(const struct bfs_parser *parser, struct bfs_expr *expr, bool casefold) { - if (!expr) { - return NULL; - } - - expr->pattern = expr->argv[1]; - - if (casefold) { -#ifdef FNM_CASEFOLD - expr->fnm_flags = FNM_CASEFOLD; -#else - parse_expr_error(parser, expr, "Missing platform support.\n"); - return NULL; -#endif - } else { - expr->fnm_flags = 0; - } - - // POSIX says, about fnmatch(): - // - // If pattern ends with an unescaped , fnmatch() shall - // return a non-zero value (indicating either no match or an error). - // - // But not all implementations obey this, so check for it ourselves. - size_t i, len = strlen(expr->pattern); - for (i = 0; i < len; ++i) { - if (expr->pattern[len - i - 1] != '\\') { - break; - } - } - if (i % 2 != 0) { - parse_expr_warning(parser, expr, "Unescaped trailing backslash.\n\n"); - expr->eval_fn = eval_false; - return expr; - } - - // strcmp() can be much faster than fnmatch() since it doesn't have to - // parse the pattern, so special-case patterns with no wildcards. - // - // https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_13_01 - expr->literal = strcspn(expr->pattern, "?*\\[") == len; - - return expr; -} - /** * Parse -i?name. */ @@ -2767,6 +2780,10 @@ static struct bfs_expr *parse_help(struct bfs_parser *parser, int arg1, int arg2 #if BFS_CAN_CHECK_CAPABILITIES cfprintf(cout, " ${blu}-capable${rs}\n"); cfprintf(cout, " Find files with POSIX.1e capabilities set\n"); +#endif +#if BFS_CAN_CHECK_CONTEXT + cfprintf(cout, " ${blu}-context${rs} ${bld}GLOB${rs}\n"); + cfprintf(cout, " Find files with SELinux context matching a glob pattern\n"); #endif cfprintf(cout, " ${blu}-depth${rs} ${bld}[-+]N${rs}\n"); cfprintf(cout, " Find files with depth ${bld}N${rs}\n"); @@ -2961,6 +2978,7 @@ static const struct table_entry parse_table[] = { {"-cmin", T_TEST, parse_min, BFS_STAT_CTIME}, {"-cnewer", T_TEST, parse_newer, BFS_STAT_CTIME}, {"-color", T_OPTION, parse_color, true}, + {"-context", T_TEST, parse_context, true}, {"-csince", T_TEST, parse_since, BFS_STAT_CTIME}, {"-ctime", T_TEST, parse_time, BFS_STAT_CTIME}, {"-d", T_FLAG, parse_depth}, -- cgit v1.2.3