* which is what it's designed for.
*/
#include "cache.h"
+#include "strbuf.h"
static char bad_path[] = "/bad-path/";
return -1;
}
-static char *user_path(char *buf, char *path, int sz)
+static struct passwd *getpw_str(const char *username, size_t len)
{
struct passwd *pw;
- char *slash;
- int len, baselen;
+ char *username_z = xmalloc(len + 1);
+ memcpy(username_z, username, len);
+ username_z[len] = '\0';
+ pw = getpwnam(username_z);
+ free(username_z);
+ return pw;
+}
- if (!path || path[0] != '~')
- return NULL;
- path++;
- slash = strchr(path, '/');
- if (path[0] == '/' || !path[0]) {
- pw = getpwuid(getuid());
- }
- else {
- if (slash) {
- *slash = 0;
- pw = getpwnam(path);
- *slash = '/';
+/*
+ * Return a string with ~ and ~user expanded via getpw*. If buf != NULL,
+ * then it is a newly allocated string. Returns NULL on getpw failure or
+ * if path is NULL.
+ */
+char *expand_user_path(const char *path)
+{
+ struct strbuf user_path = STRBUF_INIT;
+ const char *first_slash = strchrnul(path, '/');
+ const char *to_copy = path;
+
+ if (path == NULL)
+ goto return_null;
+ if (path[0] == '~') {
+ const char *username = path + 1;
+ size_t username_len = first_slash - username;
+ if (username_len == 0) {
+ const char *home = getenv("HOME");
+ strbuf_add(&user_path, home, strlen(home));
+ } else {
+ struct passwd *pw = getpw_str(username, username_len);
+ if (!pw)
+ goto return_null;
+ strbuf_add(&user_path, pw->pw_dir, strlen(pw->pw_dir));
}
- else
- pw = getpwnam(path);
+ to_copy = first_slash;
}
- if (!pw || !pw->pw_dir || sz <= strlen(pw->pw_dir))
- return NULL;
- baselen = strlen(pw->pw_dir);
- memcpy(buf, pw->pw_dir, baselen);
- while ((1 < baselen) && (buf[baselen-1] == '/')) {
- buf[baselen-1] = 0;
- baselen--;
- }
- if (slash && slash[1]) {
- len = strlen(slash);
- if (sz <= baselen + len)
- return NULL;
- memcpy(buf + baselen, slash, len + 1);
- }
- return buf;
+ strbuf_add(&user_path, to_copy, strlen(to_copy));
+ return strbuf_detach(&user_path, NULL);
+return_null:
+ strbuf_release(&user_path);
+ return NULL;
}
/*
if (PATH_MAX <= len)
return NULL;
if (path[0] == '~') {
- if (!user_path(used_path, path, PATH_MAX))
+ char *newpath = expand_user_path(path);
+ if (!newpath || (PATH_MAX - 10 < strlen(newpath))) {
+ free(newpath);
return NULL;
+ }
+ /*
+ * Copy back into the static buffer. A pity
+ * since newpath was not bounded, but other
+ * branches of the if are limited by PATH_MAX
+ * anyway.
+ */
+ strcpy(used_path, newpath); free(newpath);
strcpy(validated_path, path);
path = used_path;
}