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-rw-r--r--bsd/freebsd/contrib/ntp/sntp/libopts/compat/pathfind.c294
1 files changed, 294 insertions, 0 deletions
diff --git a/bsd/freebsd/contrib/ntp/sntp/libopts/compat/pathfind.c b/bsd/freebsd/contrib/ntp/sntp/libopts/compat/pathfind.c
new file mode 100644
index 0000000..d343dcc
--- /dev/null
+++ b/bsd/freebsd/contrib/ntp/sntp/libopts/compat/pathfind.c
@@ -0,0 +1,294 @@
+/* -*- Mode: C -*- */
+
+/* pathfind.c --- find a FILE MODE along PATH */
+
+/* Author: Gary V Vaughan <gvaughan@oranda.demon.co.uk> */
+
+/* Code: */
+
+static char *
+pathfind( char const * path,
+ char const * fname,
+ char const * mode );
+
+#include "compat.h"
+#ifndef HAVE_PATHFIND
+#if defined(__windows__) && !defined(__CYGWIN__)
+static char *
+pathfind( char const * path,
+ char const * fname,
+ char const * mode )
+{
+ return strdup(fname);
+}
+#else
+
+static char * make_absolute(char const * string, char const * dot_path);
+static char * canonicalize_pathname(char * path);
+static char * extract_colon_unit(char * dir, char const * string, int * p_index);
+
+/**
+ * local implementation of pathfind.
+ * @param[in] path colon separated list of directories
+ * @param[in] fname the name we are hunting for
+ * @param[in] mode the required file mode
+ * @returns an allocated string with the full path, or NULL
+ */
+static char *
+pathfind( char const * path,
+ char const * fname,
+ char const * mode )
+{
+ int p_index = 0;
+ int mode_bits = 0;
+ char * res_path = NULL;
+ char zPath[ AG_PATH_MAX + 1 ];
+
+ if (strchr( mode, 'r' )) mode_bits |= R_OK;
+ if (strchr( mode, 'w' )) mode_bits |= W_OK;
+ if (strchr( mode, 'x' )) mode_bits |= X_OK;
+
+ /*
+ * FOR each non-null entry in the colon-separated path, DO ...
+ */
+ for (;;) {
+ DIR * dirP;
+ char * colon_unit = extract_colon_unit( zPath, path, &p_index );
+
+ if (colon_unit == NULL)
+ break;
+
+ dirP = opendir( colon_unit );
+
+ /*
+ * IF the directory is inaccessable, THEN next directory
+ */
+ if (dirP == NULL)
+ continue;
+
+ for (;;) {
+ struct dirent *entP = readdir( dirP );
+
+ if (entP == (struct dirent *)NULL)
+ break;
+
+ /*
+ * IF the file name matches the one we are looking for, ...
+ */
+ if (strcmp(entP->d_name, fname) == 0) {
+ char * abs_name = make_absolute(fname, colon_unit);
+
+ /*
+ * Make sure we can access it in the way we want
+ */
+ if (access(abs_name, mode_bits) >= 0) {
+ /*
+ * We can, so normalize the name and return it below
+ */
+ res_path = canonicalize_pathname(abs_name);
+ }
+
+ free(abs_name);
+ break;
+ }
+ }
+
+ closedir( dirP );
+
+ if (res_path != NULL)
+ break;
+ }
+
+ return res_path;
+}
+
+/*
+ * Turn STRING (a pathname) into an absolute pathname, assuming that
+ * DOT_PATH contains the symbolic location of `.'. This always returns
+ * a new string, even if STRING was an absolute pathname to begin with.
+ */
+static char *
+make_absolute( char const * string, char const * dot_path )
+{
+ char * result;
+ int result_len;
+
+ if (!dot_path || *string == '/') {
+ result = strdup( string );
+ if (result == NULL) {
+ return NULL; /* couldn't allocate memory */
+ }
+ } else {
+ if (dot_path && dot_path[0]) {
+ result = malloc( 2 + strlen( dot_path ) + strlen( string ) );
+ if (result == NULL) {
+ return NULL; /* couldn't allocate memory */
+ }
+ strcpy( result, dot_path );
+ result_len = (int)strlen(result);
+ if (result[result_len - 1] != '/') {
+ result[result_len++] = '/';
+ result[result_len] = '\0';
+ }
+ } else {
+ result = malloc( 3 + strlen( string ) );
+ if (result == NULL) {
+ return NULL; /* couldn't allocate memory */
+ }
+ result[0] = '.'; result[1] = '/'; result[2] = '\0';
+ result_len = 2;
+ }
+
+ strcpy( result + result_len, string );
+ }
+
+ return result;
+}
+
+/*
+ * Canonicalize PATH, and return a new path. The new path differs from
+ * PATH in that:
+ *
+ * Multiple `/'s are collapsed to a single `/'.
+ * Leading `./'s are removed.
+ * Trailing `/.'s are removed.
+ * Trailing `/'s are removed.
+ * Non-leading `../'s and trailing `..'s are handled by removing
+ * portions of the path.
+ */
+static char *
+canonicalize_pathname( char *path )
+{
+ int i, start;
+ char stub_char, *result;
+
+ /* The result cannot be larger than the input PATH. */
+ result = strdup( path );
+ if (result == NULL) {
+ return NULL; /* couldn't allocate memory */
+ }
+ stub_char = (*path == '/') ? '/' : '.';
+
+ /* Walk along RESULT looking for things to compact. */
+ i = 0;
+ while (result[i]) {
+ while (result[i] != '\0' && result[i] != '/')
+ i++;
+
+ start = i++;
+
+ /* If we didn't find any slashes, then there is nothing left to
+ * do.
+ */
+ if (!result[start])
+ break;
+
+ /* Handle multiple `/'s in a row. */
+ while (result[i] == '/')
+ i++;
+
+#if !defined (apollo)
+ if ((start + 1) != i)
+#else
+ if ((start + 1) != i && (start != 0 || i != 2))
+#endif /* apollo */
+ {
+ strcpy( result + start + 1, result + i );
+ i = start + 1;
+ }
+
+ /* Handle backquoted `/'. */
+ if (start > 0 && result[start - 1] == '\\')
+ continue;
+
+ /* Check for trailing `/', and `.' by itself. */
+ if ((start && !result[i])
+ || (result[i] == '.' && !result[i+1])) {
+ result[--i] = '\0';
+ break;
+ }
+
+ /* Check for `../', `./' or trailing `.' by itself. */
+ if (result[i] == '.') {
+ /* Handle `./'. */
+ if (result[i + 1] == '/') {
+ strcpy( result + i, result + i + 1 );
+ i = (start < 0) ? 0 : start;
+ continue;
+ }
+
+ /* Handle `../' or trailing `..' by itself. */
+ if (result[i + 1] == '.' &&
+ (result[i + 2] == '/' || !result[i + 2])) {
+ while (--start > -1 && result[start] != '/')
+ ;
+ strcpy( result + start + 1, result + i + 2 );
+ i = (start < 0) ? 0 : start;
+ continue;
+ }
+ }
+ }
+
+ if (!*result) {
+ *result = stub_char;
+ result[1] = '\0';
+ }
+
+ return result;
+}
+
+/*
+ * Given a string containing units of information separated by colons,
+ * return the next one pointed to by (P_INDEX), or NULL if there are no
+ * more. Advance (P_INDEX) to the character after the colon.
+ */
+static char *
+extract_colon_unit(char * pzDir, char const * string, int * p_index)
+{
+ char * pzDest = pzDir;
+ int ix = *p_index;
+
+ if (string == NULL)
+ return NULL;
+
+ if ((unsigned)ix >= strlen( string ))
+ return NULL;
+
+ {
+ char const * pzSrc = string + ix;
+
+ while (*pzSrc == ':') pzSrc++;
+
+ for (;;) {
+ char ch = (*(pzDest++) = *(pzSrc++));
+ switch (ch) {
+ case ':':
+ pzDest[-1] = NUL;
+ /* FALLTHROUGH */
+ case NUL:
+ goto copy_done;
+ }
+
+ if ((unsigned long)(pzDest - pzDir) >= AG_PATH_MAX)
+ break;
+ } copy_done:;
+
+ ix = (int)(pzSrc - string);
+ }
+
+ if (*pzDir == NUL)
+ return NULL;
+
+ *p_index = ix;
+ return pzDir;
+}
+#endif /* __windows__ / __CYGWIN__ */
+#endif /* HAVE_PATHFIND */
+
+/*
+ * Local Variables:
+ * mode: C
+ * c-file-style: "stroustrup"
+ * indent-tabs-mode: nil
+ * End:
+ * end of compat/pathfind.c */
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