/* vi: set sw=4 ts=4: */ /* * test implementation for busybox * * Copyright (c) by a whole pile of folks: * * test(1); version 7-like -- author Erik Baalbergen * modified by Eric Gisin to be used as built-in. * modified by Arnold Robbins to add SVR3 compatibility * (-x -c -b -p -u -g -k) plus Korn's -L -nt -ot -ef and new -S (socket). * modified by J.T. Conklin for NetBSD. * modified by Herbert Xu to be used as built-in in ash. * modified by Erik Andersen <andersen@codepoet.org> to be used * in busybox. * modified by Bernhard Fischer to be useable (i.e. a bit less bloaty). * * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. * * Original copyright notice states: * "This program is in the Public Domain." */ #include "libbb.h" #include <setjmp.h> /* This is a NOFORK applet. Be very careful! */ /* test_main() is called from shells, and we need to be extra careful here. * This is true regardless of PREFER_APPLETS and STANDALONE_SHELL * state. */ /* test(1) accepts the following grammar: oexpr ::= aexpr | aexpr "-o" oexpr ; aexpr ::= nexpr | nexpr "-a" aexpr ; nexpr ::= primary | "!" primary primary ::= unary-operator operand | operand binary-operator operand | operand | "(" oexpr ")" ; unary-operator ::= "-r"|"-w"|"-x"|"-f"|"-d"|"-c"|"-b"|"-p"| "-u"|"-g"|"-k"|"-s"|"-t"|"-z"|"-n"|"-o"|"-O"|"-G"|"-L"|"-S"; binary-operator ::= "="|"=="|"!="|"-eq"|"-ne"|"-ge"|"-gt"|"-le"|"-lt"| "-nt"|"-ot"|"-ef"; operand ::= <any legal UNIX file name> */ enum token { EOI, FILRD, FILWR, FILEX, FILEXIST, FILREG, FILDIR, FILCDEV, FILBDEV, FILFIFO, FILSOCK, FILSYM, FILGZ, FILTT, FILSUID, FILSGID, FILSTCK, FILNT, FILOT, FILEQ, FILUID, FILGID, STREZ, STRNZ, STREQ, STRNE, STRLT, STRGT, INTEQ, INTNE, INTGE, INTGT, INTLE, INTLT, UNOT, BAND, BOR, LPAREN, RPAREN, OPERAND }; #define is_int_op(a) (((unsigned char)((a) - INTEQ)) <= 5) #define is_str_op(a) (((unsigned char)((a) - STREZ)) <= 5) #define is_file_op(a) (((unsigned char)((a) - FILNT)) <= 2) #define is_file_access(a) (((unsigned char)((a) - FILRD)) <= 2) #define is_file_type(a) (((unsigned char)((a) - FILREG)) <= 5) #define is_file_bit(a) (((unsigned char)((a) - FILSUID)) <= 2) enum token_types { UNOP, BINOP, BUNOP, BBINOP, PAREN }; static const struct t_op { char op_text[4]; unsigned char op_num, op_type; } ops[] = { { "-r", FILRD , UNOP }, { "-w", FILWR , UNOP }, { "-x", FILEX , UNOP }, { "-e", FILEXIST, UNOP }, { "-f", FILREG , UNOP }, { "-d", FILDIR , UNOP }, { "-c", FILCDEV , UNOP }, { "-b", FILBDEV , UNOP }, { "-p", FILFIFO , UNOP }, { "-u", FILSUID , UNOP }, { "-g", FILSGID , UNOP }, { "-k", FILSTCK , UNOP }, { "-s", FILGZ , UNOP }, { "-t", FILTT , UNOP }, { "-z", STREZ , UNOP }, { "-n", STRNZ , UNOP }, { "-h", FILSYM , UNOP }, /* for backwards compat */ { "-O" , FILUID , UNOP }, { "-G" , FILGID , UNOP }, { "-L" , FILSYM , UNOP }, { "-S" , FILSOCK, UNOP }, { "=" , STREQ , BINOP }, { "==" , STREQ , BINOP }, { "!=" , STRNE , BINOP }, { "<" , STRLT , BINOP }, { ">" , STRGT , BINOP }, { "-eq", INTEQ , BINOP }, { "-ne", INTNE , BINOP }, { "-ge", INTGE , BINOP }, { "-gt", INTGT , BINOP }, { "-le", INTLE , BINOP }, { "-lt", INTLT , BINOP }, { "-nt", FILNT , BINOP }, { "-ot", FILOT , BINOP }, { "-ef", FILEQ , BINOP }, { "!" , UNOT , BUNOP }, { "-a" , BAND , BBINOP }, { "-o" , BOR , BBINOP }, { "(" , LPAREN , PAREN }, { ")" , RPAREN , PAREN }, }; #if ENABLE_FEATURE_TEST_64 typedef int64_t arith_t; #else typedef int arith_t; #endif /* We try to minimize both static and stack usage. */ struct test_statics { char **t_wp; const struct t_op *t_wp_op; gid_t *group_array; int ngroups; jmp_buf leaving; }; /* See test_ptr_hack.c */ extern struct test_statics *const test_ptr_to_statics; #define S (*test_ptr_to_statics) #define t_wp (S.t_wp ) #define t_wp_op (S.t_wp_op ) #define group_array (S.group_array ) #define ngroups (S.ngroups ) #define leaving (S.leaving ) #define INIT_S() do { \ (*(struct test_statics**)&test_ptr_to_statics) = xzalloc(sizeof(S)); \ barrier(); \ } while (0) #define DEINIT_S() do { \ free(test_ptr_to_statics); \ } while (0) static arith_t primary(enum token n); static void syntax(const char *op, const char *msg) ATTRIBUTE_NORETURN; static void syntax(const char *op, const char *msg) { if (op && *op) { bb_error_msg("%s: %s", op, msg); } else { bb_error_msg("%s: %s"+4, msg); } longjmp(leaving, 2); } /* atoi with error detection */ //XXX: FIXME: duplicate of existing libbb function? static arith_t getn(const char *s) { char *p; #if ENABLE_FEATURE_TEST_64 long long r; #else long r; #endif errno = 0; #if ENABLE_FEATURE_TEST_64 r = strtoll(s, &p, 10); #else r = strtol(s, &p, 10); #endif if (errno != 0) syntax(s, "out of range"); if (*(skip_whitespace(p))) syntax(s, "bad number"); return r; } /* UNUSED static int newerf(const char *f1, const char *f2) { struct stat b1, b2; return (stat(f1, &b1) == 0 && stat(f2, &b2) == 0 && b1.st_mtime > b2.st_mtime); } static int olderf(const char *f1, const char *f2) { struct stat b1, b2; return (stat(f1, &b1) == 0 && stat(f2, &b2) == 0 && b1.st_mtime < b2.st_mtime); } static int equalf(const char *f1, const char *f2) { struct stat b1, b2; return (stat(f1, &b1) == 0 && stat(f2, &b2) == 0 && b1.st_dev == b2.st_dev && b1.st_ino == b2.st_ino); } */ static enum token t_lex(char *s) { const struct t_op *op; t_wp_op = NULL; if (s == NULL) { return EOI; } op = ops; do { if (strcmp(s, op->op_text) == 0) { t_wp_op = op; return op->op_num; } op++; } while (op < ops + ARRAY_SIZE(ops)); return OPERAND; } static int binop(void) { const char *opnd1, *opnd2; struct t_op const *op; arith_t val1, val2; opnd1 = *t_wp; (void) t_lex(*++t_wp); op = t_wp_op; opnd2 = *++t_wp; if (opnd2 == NULL) syntax(op->op_text, "argument expected"); if (is_int_op(op->op_num)) { val1 = getn(opnd1); val2 = getn(opnd2); if (op->op_num == INTEQ) return val1 == val2; if (op->op_num == INTNE) return val1 != val2; if (op->op_num == INTGE) return val1 >= val2; if (op->op_num == INTGT) return val1 > val2; if (op->op_num == INTLE) return val1 <= val2; if (op->op_num == INTLT) return val1 < val2; } if (is_str_op(op->op_num)) { val1 = strcmp(opnd1, opnd2); if (op->op_num == STREQ) return val1 == 0; if (op->op_num == STRNE) return val1 != 0; if (op->op_num == STRLT) return val1 < 0; if (op->op_num == STRGT) return val1 > 0; } /* We are sure that these three are by now the only binops we didn't check * yet, so we do not check if the class is correct: */ /* if (is_file_op(op->op_num)) */ { struct stat b1, b2; if (stat(opnd1, &b1) || stat(opnd2, &b2)) return 0; /* false, since at least one stat failed */ if (op->op_num == FILNT) return b1.st_mtime > b2.st_mtime; if (op->op_num == FILOT) return b1.st_mtime < b2.st_mtime; if (op->op_num == FILEQ) return b1.st_dev == b2.st_dev && b1.st_ino == b2.st_ino; } return 1; /* NOTREACHED */ } static void initialize_group_array(void) { ngroups = getgroups(0, NULL); if (ngroups > 0) { /* FIXME: ash tries so hard to not die on OOM, * and we spoil it with just one xrealloc here */ /* We realloc, because test_main can be entered repeatedly by shell. * Testcase (ash): 'while true; do test -x some_file; done' * and watch top. (some_file must have owner != you) */ group_array = xrealloc(group_array, ngroups * sizeof(gid_t)); getgroups(ngroups, group_array); } } /* Return non-zero if GID is one that we have in our groups list. */ //XXX: FIXME: duplicate of existing libbb function? // see toplevel TODO file: // possible code duplication ingroup() and is_a_group_member() static int is_a_group_member(gid_t gid) { int i; /* Short-circuit if possible, maybe saving a call to getgroups(). */ if (gid == getgid() || gid == getegid()) return 1; if (ngroups == 0) initialize_group_array(); /* Search through the list looking for GID. */ for (i = 0; i < ngroups; i++) if (gid == group_array[i]) return 1; return 0; } /* Do the same thing access(2) does, but use the effective uid and gid, and don't make the mistake of telling root that any file is executable. */ static int test_eaccess(char *path, int mode) { struct stat st; unsigned int euid = geteuid(); if (stat(path, &st) < 0) return -1; if (euid == 0) { /* Root can read or write any file. */ if (mode != X_OK) return 0; /* Root can execute any file that has any one of the execute bits set. */ if (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) return 0; } if (st.st_uid == euid) /* owner */ mode <<= 6; else if (is_a_group_member(st.st_gid)) mode <<= 3; if (st.st_mode & mode) return 0; return -1; } static int filstat(char *nm, enum token mode) { struct stat s; unsigned i = i; /* gcc 3.x thinks it can be used uninitialized */ if (mode == FILSYM) { #ifdef S_IFLNK if (lstat(nm, &s) == 0) { i = S_IFLNK; goto filetype; } #endif return 0; } if (stat(nm, &s) != 0) return 0; if (mode == FILEXIST) return 1; if (is_file_access(mode)) { if (mode == FILRD) i = R_OK; if (mode == FILWR) i = W_OK; if (mode == FILEX) i = X_OK; return test_eaccess(nm, i) == 0; } if (is_file_type(mode)) { if (mode == FILREG) i = S_IFREG; if (mode == FILDIR) i = S_IFDIR; if (mode == FILCDEV) i = S_IFCHR; if (mode == FILBDEV) i = S_IFBLK; if (mode == FILFIFO) { #ifdef S_IFIFO i = S_IFIFO; #else return 0; #endif } if (mode == FILSOCK) { #ifdef S_IFSOCK i = S_IFSOCK; #else return 0; #endif } filetype: return ((s.st_mode & S_IFMT) == i); } if (is_file_bit(mode)) { if (mode == FILSUID) i = S_ISUID; if (mode == FILSGID) i = S_ISGID; if (mode == FILSTCK) i = S_ISVTX; return ((s.st_mode & i) != 0); } if (mode == FILGZ) return s.st_size > 0L; if (mode == FILUID) return s.st_uid == geteuid(); if (mode == FILGID) return s.st_gid == getegid(); return 1; /* NOTREACHED */ } static arith_t nexpr(enum token n) { if (n == UNOT) return !nexpr(t_lex(*++t_wp)); return primary(n); } static arith_t aexpr(enum token n) { arith_t res; res = nexpr(n); if (t_lex(*++t_wp) == BAND) return aexpr(t_lex(*++t_wp)) && res; t_wp--; return res; } static arith_t oexpr(enum token n) { arith_t res; res = aexpr(n); if (t_lex(*++t_wp) == BOR) { return oexpr(t_lex(*++t_wp)) || res; } t_wp--; return res; } static arith_t primary(enum token n) { arith_t res; if (n == EOI) { syntax(NULL, "argument expected"); } if (n == LPAREN) { res = oexpr(t_lex(*++t_wp)); if (t_lex(*++t_wp) != RPAREN) syntax(NULL, "closing paren expected"); return res; } if (t_wp_op && t_wp_op->op_type == UNOP) { /* unary expression */ if (*++t_wp == NULL) syntax(t_wp_op->op_text, "argument expected"); if (n == STREZ) return t_wp[0][0] == '\0'; if (n == STRNZ) return t_wp[0][0] != '\0'; if (n == FILTT) return isatty(getn(*t_wp)); return filstat(*t_wp, n); } t_lex(t_wp[1]); if (t_wp_op && t_wp_op->op_type == BINOP) { return binop(); } return t_wp[0][0] != '\0'; } int test_main(int argc, char **argv) { int res; const char *arg0; bool negate = 0; arg0 = bb_basename(argv[0]); if (arg0[0] == '[') { --argc; if (!arg0[1]) { /* "[" ? */ if (NOT_LONE_CHAR(argv[argc], ']')) { bb_error_msg("missing ]"); return 2; } } else { /* assuming "[[" */ if (strcmp(argv[argc], "]]") != 0) { bb_error_msg("missing ]]"); return 2; } } argv[argc] = NULL; } /* We must do DEINIT_S() prior to returning */ INIT_S(); res = setjmp(leaving); if (res) goto ret; /* resetting ngroups is probably unnecessary. it will * force a new call to getgroups(), which prevents using * group data fetched during a previous call. but the * only way the group data could be stale is if there's * been an intervening call to setgroups(), and this * isn't likely in the case of a shell. paranoia * prevails... */ ngroups = 0; //argc--; argv++; /* Implement special cases from POSIX.2, section 4.62.4 */ if (!argv[0]) { /* "test" */ res = 1; goto ret; } if (LONE_CHAR(argv[0], '!') && argv[1]) { negate = 1; //argc--; argv++; } if (!argv[1]) { /* "test [!] arg" */ res = (*argv[0] == '\0'); goto ret; } if (argv[2] && !argv[3]) { t_lex(argv[1]); if (t_wp_op && t_wp_op->op_type == BINOP) { /* "test [!] arg1 <binary_op> arg2" */ t_wp = &argv[0]; res = (binop() == 0); goto ret; } } /* Some complex expression. Undo '!' removal */ if (negate) { negate = 0; //argc++; argv--; } t_wp = &argv[0]; res = !oexpr(t_lex(*t_wp)); if (*t_wp != NULL && *++t_wp != NULL) { bb_error_msg("%s: unknown operand", *t_wp); res = 2; } ret: DEINIT_S(); return negate ? !res : res; }