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Diffstat (limited to 'test.c')
| -rw-r--r-- | test.c | 583 |
1 files changed, 583 insertions, 0 deletions
@@ -0,0 +1,583 @@ +/* vi: set sw=4 ts=4: */ +/* + * echo 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 <andersee@debian.org> to be used + * in busybox. + * + * 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 02111-1307 USA + * + * Original copyright notice states: + * "This program is in the Public Domain." + */ + +#include "internal.h" +#include <sys/types.h> +#include <sys/stat.h> +#include <unistd.h> +#include <ctype.h> +#include <errno.h> +#include <stdlib.h> +#include <string.h> + +/* 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 +}; + +enum token_types { + UNOP, + BINOP, + BUNOP, + BBINOP, + PAREN +}; + +struct t_op { + const char *op_text; + short op_num, op_type; +} const 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}, + {"!=", 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}, + {0, 0, 0} +}; + +char **t_wp; +struct t_op const *t_wp_op; +static gid_t *group_array = NULL; +static int ngroups; + +static enum token t_lex(); +static int oexpr(); +static int aexpr(); +static int nexpr(); +static int binop(); +static int primary(); +static int filstat(); +static int getn(); +static int newerf(); +static int olderf(); +static int equalf(); +static void syntax(); +static int test_eaccess(); +static int is_a_group_member(); +static void initialize_group_array(); + +extern int +test_main(int argc, char** argv) +{ + int res; + + if (strcmp(argv[0], "[") == 0) { + if (strcmp(argv[--argc], "]")) + fatalError("missing ]"); + argv[argc] = NULL; + } + + /* Implement special cases from POSIX.2, section 4.62.4 */ + switch (argc) { + case 1: + exit( 1); + case 2: + exit (*argv[1] == '\0'); + case 3: + if (argv[1][0] == '!' && argv[1][1] == '\0') { + exit (!(*argv[2] == '\0')); + } + break; + case 4: + if (argv[1][0] != '!' || argv[1][1] != '\0') { + if (t_lex(argv[2]), + t_wp_op && t_wp_op->op_type == BINOP) { + t_wp = &argv[1]; + exit (binop() == 0); + } + } + break; + case 5: + if (argv[1][0] == '!' && argv[1][1] == '\0') { + if (t_lex(argv[3]), + t_wp_op && t_wp_op->op_type == BINOP) { + t_wp = &argv[2]; + exit (!(binop() == 0)); + } + } + break; + } + + t_wp = &argv[1]; + res = !oexpr(t_lex(*t_wp)); + + if (*t_wp != NULL && *++t_wp != NULL) + syntax(*t_wp, "unknown operand"); + + exit( res); +} + +static void +syntax(op, msg) + char *op; + char *msg; +{ + if (op && *op) + fatalError("%s: %s", op, msg); + else + fatalError("%s", msg); +} + +static int +oexpr(n) + enum token n; +{ + int res; + + res = aexpr(n); + if (t_lex(*++t_wp) == BOR) + return oexpr(t_lex(*++t_wp)) || res; + t_wp--; + return res; +} + +static int +aexpr(n) + enum token n; +{ + int res; + + res = nexpr(n); + if (t_lex(*++t_wp) == BAND) + return aexpr(t_lex(*++t_wp)) && res; + t_wp--; + return res; +} + +static int +nexpr(n) + enum token n; /* token */ +{ + if (n == UNOT) + return !nexpr(t_lex(*++t_wp)); + return primary(n); +} + +static int +primary(n) + enum token n; +{ + int 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"); + switch (n) { + case STREZ: + return strlen(*t_wp) == 0; + case STRNZ: + return strlen(*t_wp) != 0; + case FILTT: + return isatty(getn(*t_wp)); + default: + return filstat(*t_wp, n); + } + } + + if (t_lex(t_wp[1]), t_wp_op && t_wp_op->op_type == BINOP) { + return binop(); + } + + return strlen(*t_wp) > 0; +} + +static int +binop() +{ + const char *opnd1, *opnd2; + struct t_op const *op; + + opnd1 = *t_wp; + (void) t_lex(*++t_wp); + op = t_wp_op; + + if ((opnd2 = *++t_wp) == (char *)0) + syntax(op->op_text, "argument expected"); + + switch (op->op_num) { + case STREQ: + return strcmp(opnd1, opnd2) == 0; + case STRNE: + return strcmp(opnd1, opnd2) != 0; + case STRLT: + return strcmp(opnd1, opnd2) < 0; + case STRGT: + return strcmp(opnd1, opnd2) > 0; + case INTEQ: + return getn(opnd1) == getn(opnd2); + case INTNE: + return getn(opnd1) != getn(opnd2); + case INTGE: + return getn(opnd1) >= getn(opnd2); + case INTGT: + return getn(opnd1) > getn(opnd2); + case INTLE: + return getn(opnd1) <= getn(opnd2); + case INTLT: + return getn(opnd1) < getn(opnd2); + case FILNT: + return newerf (opnd1, opnd2); + case FILOT: + return olderf (opnd1, opnd2); + case FILEQ: + return equalf (opnd1, opnd2); + } + /* NOTREACHED */ + return 1; +} + +static int +filstat(nm, mode) + char *nm; + enum token mode; +{ + struct stat s; + int i; + + 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; + + switch (mode) { + case FILRD: + return test_eaccess(nm, R_OK) == 0; + case FILWR: + return test_eaccess(nm, W_OK) == 0; + case FILEX: + return test_eaccess(nm, X_OK) == 0; + case FILEXIST: + return 1; + case FILREG: + i = S_IFREG; + goto filetype; + case FILDIR: + i = S_IFDIR; + goto filetype; + case FILCDEV: + i = S_IFCHR; + goto filetype; + case FILBDEV: + i = S_IFBLK; + goto filetype; + case FILFIFO: +#ifdef S_IFIFO + i = S_IFIFO; + goto filetype; +#else + return 0; +#endif + case FILSOCK: +#ifdef S_IFSOCK + i = S_IFSOCK; + goto filetype; +#else + return 0; +#endif + case FILSUID: + i = S_ISUID; + goto filebit; + case FILSGID: + i = S_ISGID; + goto filebit; + case FILSTCK: + i = S_ISVTX; + goto filebit; + case FILGZ: + return s.st_size > 0L; + case FILUID: + return s.st_uid == geteuid(); + case FILGID: + return s.st_gid == getegid(); + default: + return 1; + } + +filetype: + return ((s.st_mode & S_IFMT) == i); + +filebit: + return ((s.st_mode & i) != 0); +} + +static enum token +t_lex(s) + char *s; +{ + struct t_op const *op = ops; + + if (s == 0) { + t_wp_op = (struct t_op *)0; + return EOI; + } + while (op->op_text) { + if (strcmp(s, op->op_text) == 0) { + t_wp_op = op; + return op->op_num; + } + op++; + } + t_wp_op = (struct t_op *)0; + return OPERAND; +} + +/* atoi with error detection */ +static int +getn(s) + char *s; +{ + char *p; + long r; + + errno = 0; + r = strtol(s, &p, 10); + + if (errno != 0) + fatalError("%s: out of range", s); + + while (isspace(*p)) + p++; + + if (*p) + fatalError("%s: bad number", s); + + return (int) r; +} + +static int +newerf (f1, f2) +char *f1, *f2; +{ + struct stat b1, b2; + + return (stat (f1, &b1) == 0 && + stat (f2, &b2) == 0 && + b1.st_mtime > b2.st_mtime); +} + +static int +olderf (f1, f2) +char *f1, *f2; +{ + struct stat b1, b2; + + return (stat (f1, &b1) == 0 && + stat (f2, &b2) == 0 && + b1.st_mtime < b2.st_mtime); +} + +static int +equalf (f1, f2) +char *f1, *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); +} + +/* 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 (path, mode) +char *path; +int mode; +{ + struct stat st; + 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 void +initialize_group_array () +{ + ngroups = getgroups(0, NULL); + if ((group_array = realloc(group_array, ngroups * sizeof(gid_t))) == NULL) + fatalError("Out of space"); + + getgroups(ngroups, group_array); +} + +/* Return non-zero if GID is one that we have in our groups list. */ +static int +is_a_group_member (gid) +gid_t gid; +{ + register 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); +} |