Index: uspace/srv/vfs/vfs_lookup.c =================================================================== --- uspace/srv/vfs/vfs_lookup.c (revision d6084ef92b6611a19749ebcfb70d5730dc0cb07b) +++ uspace/srv/vfs/vfs_lookup.c (revision 739d00a5a284b6a2bd289fe1fd2395c3788b094d) @@ -36,19 +36,16 @@ */ +#include "vfs.h" #include #include #include #include -#include #include #include #include #include -#include "vfs.h" +#include #define min(a, b) ((a) < (b) ? (a) : (b)) - -/* Forward static declarations. */ -static char *canonify(char *path, size_t *lenp); atomic_t plb_futex = FUTEX_INITIALIZER; @@ -181,301 +178,4 @@ } -/** Token types used for tokenization of path. */ -typedef enum { - TK_INVALID, - TK_SLASH, - TK_DOT, - TK_DOTDOT, - TK_COMP, - TK_NUL -} tokval_t; - -typedef struct { - tokval_t kind; - char *start; - char *stop; -} token_t; - -/** Fake up the TK_SLASH token. */ -static token_t slash_token(char *start) -{ - token_t ret; - ret.kind = TK_SLASH; - ret.start = start; - ret.stop = start; - return ret; -} - -/** Given a token, return the next token. */ -static token_t next_token(token_t *cur) -{ - token_t ret; - - if (cur->stop[1] == '\0') { - ret.kind = TK_NUL; - ret.start = cur->stop + 1; - ret.stop = ret.start; - return ret; - } - if (cur->stop[1] == '/') { - ret.kind = TK_SLASH; - ret.start = cur->stop + 1; - ret.stop = ret.start; - return ret; - } - if (cur->stop[1] == '.' && (!cur->stop[2] || cur->stop[2] == '/')) { - ret.kind = TK_DOT; - ret.start = cur->stop + 1; - ret.stop = ret.start; - return ret; - } - if (cur->stop[1] == '.' && cur->stop[2] == '.' && - (!cur->stop[3] || cur->stop[3] == '/')) { - ret.kind = TK_DOTDOT; - ret.start = cur->stop + 1; - ret.stop = cur->stop + 2; - return ret; - } - unsigned i; - for (i = 1; cur->stop[i] && cur->stop[i] != '/'; i++) - ; - ret.kind = TK_COMP; - ret.start = &cur->stop[1]; - ret.stop = &cur->stop[i - 1]; - return ret; -} - -/** States used by canonify(). */ -typedef enum { - S_INI, - S_A, - S_B, - S_C, - S_ACCEPT, - S_RESTART, - S_REJECT -} state_t; - -typedef struct { - state_t s; - void (* f)(token_t *, token_t *, token_t *); -} change_state_t; - -/* - * Actions that can be performed when transitioning from one - * state of canonify() to another. - */ -static void set_first_slash(token_t *t, token_t *tfsl, token_t *tlcomp) -{ - *tfsl = *t; -} -static void save_component(token_t *t, token_t *tfsl, token_t *tlcomp) -{ - *tlcomp = *t; -} -static void terminate_slash(token_t *t, token_t *tfsl, token_t *tlcomp) -{ - if (tfsl->stop[1]) /* avoid writing to a well-formatted path */ - tfsl->stop[1] = '\0'; -} -static void remove_trailing_slash(token_t *t, token_t *tfsl, token_t *tlcomp) -{ - t->start[-1] = '\0'; -} -/** Eat the extra '/'.. - * - * @param t The current TK_SLASH token. - */ -static void shift_slash(token_t *t, token_t *tfsl, token_t *tlcomp) -{ - char *p = t->start; - char *q = t->stop + 1; - while ((*p++ = *q++)) - ; -} -/** Eat the extra '.'. - * - * @param t The current TK_DOT token. - */ -static void shift_dot(token_t *t, token_t *tfsl, token_t *tlcomp) -{ - char *p = t->start; - char *q = t->stop + 1; - while ((*p++ = *q++)) - ; -} -/** Collapse the TK_COMP TK_SLASH TK_DOTDOT pattern. - * - * @param t The current TK_DOTDOT token. - * @param tlcomp The last TK_COMP token. - */ -static void shift_dotdot(token_t *t, token_t *tfsl, token_t *tlcomp) -{ - char *p = tlcomp->start; - char *q = t->stop + 1; - while ((*p++ = *q++)) - ; -} - -/** Transition function for canonify(). */ -static change_state_t trans[4][6] = { - [S_INI] = { - [TK_SLASH] = { - .s = S_A, - .f = set_first_slash, - }, - [TK_DOT] = { - .s = S_REJECT, - .f = NULL, - }, - [TK_DOTDOT] = { - .s = S_REJECT, - .f = NULL, - }, - [TK_COMP] = { - .s = S_REJECT, - .f = NULL, - }, - [TK_NUL] = { - .s = S_REJECT, - .f = NULL, - }, - [TK_INVALID] = { - .s = S_REJECT, - .f = NULL, - }, - }, - [S_A] = { - [TK_SLASH] = { - .s = S_A, - .f = set_first_slash, - }, - [TK_DOT] = { - .s = S_A, - .f = NULL, - }, - [TK_DOTDOT] = { - .s = S_A, - .f = NULL, - }, - [TK_COMP] = { - .s = S_B, - .f = save_component, - }, - [TK_NUL] = { - .s = S_ACCEPT, - .f = terminate_slash, - }, - [TK_INVALID] = { - .s = S_REJECT, - .f = NULL, - }, - }, - [S_B] = { - [TK_SLASH] = { - .s = S_C, - .f = NULL, - }, - [TK_DOT] = { - .s = S_REJECT, - .f = NULL, - }, - [TK_DOTDOT] = { - .s = S_REJECT, - .f = NULL, - }, - [TK_COMP] = { - .s = S_REJECT, - .f = NULL, - }, - [TK_NUL] = { - .s = S_ACCEPT, - .f = NULL, - }, - [TK_INVALID] = { - .s = S_REJECT, - .f = NULL, - }, - }, - [S_C] = { - [TK_SLASH] = { - .s = S_RESTART, - .f = shift_slash, - }, - [TK_DOT] = { - .s = S_RESTART, - .f = shift_dot, - }, - [TK_DOTDOT] = { - .s = S_RESTART, - .f = shift_dotdot, - }, - [TK_COMP] = { - .s = S_B, - .f = save_component, - }, - [TK_NUL] = { - .s = S_ACCEPT, - .f = remove_trailing_slash, - }, - [TK_INVALID] = { - .s = S_REJECT, - .f = NULL, - }, - } -}; - -/** Canonify a file system path. - * - * A file system path is canonical, if the following holds: - * 1) the path is absolute (i.e. a/b/c is not canonical) - * 2) there is no trailing slash in the path (i.e. /a/b/c is not canonical) - * 3) there is no extra slash in the path (i.e. /a//b/c is not canonical) - * 4) there is no '.' component in the path (i.e. /a/./b/c is not canonical) - * 5) there is no '..' component in the path (i.e. /a/b/../c is not canonical) - * - * This function makes a potentially non-canonical file system path canonical. - * It works in-place and requires a NULL-terminated input string. - * - * @param path Path to be canonified. - * @param lenp Pointer where the length of the final path will be - * stored. Can be NULL. - * - * @return Canonified path or NULL on failure. - */ -char *canonify(char *path, size_t *lenp) -{ - state_t state; - token_t t; - token_t tfsl; /* first slash */ - token_t tlcomp; /* last component */ - if (*path != '/') - return NULL; - tfsl = slash_token(path); -restart: - state = S_INI; - t = tfsl; - tlcomp = tfsl; - while (state != S_ACCEPT && state != S_RESTART && state != S_REJECT) { - if (trans[state][t.kind].f) - trans[state][t.kind].f(&t, &tfsl, &tlcomp); - state = trans[state][t.kind].s; - t = next_token(&t); - } - - switch (state) { - case S_RESTART: - goto restart; - case S_REJECT: - return NULL; - case S_ACCEPT: - if (lenp) - *lenp = (size_t)((tlcomp.stop - tfsl.start) + 1); - return tfsl.start; - default: - abort(); - } -} - /** * @}