diff options
Diffstat (limited to 'daemon/realpath.c')
| -rw-r--r-- | daemon/realpath.c | 31 |
1 files changed, 23 insertions, 8 deletions
diff --git a/daemon/realpath.c b/daemon/realpath.c index bfe8e676..0dc5fa5c 100644 --- a/daemon/realpath.c +++ b/daemon/realpath.c @@ -22,11 +22,12 @@ #include <stdlib.h> #include <string.h> #include <unistd.h> +#include <fcntl.h> #include <limits.h> #include <sys/types.h> #include <dirent.h> -#include "ignore-value.h" +#include "openat.h" #include "daemon.h" #include "actions.h" @@ -52,9 +53,13 @@ do_case_sensitive_path (const char *path) { char ret[PATH_MAX+1] = "/"; size_t next = 1; + int fd_cwd; - /* MUST chdir ("/") before leaving this function. */ - if (chdir (sysroot) == -1) { + /* 'fd_cwd' here is a surrogate for the current working directory, so + * that we don't have to actually call chdir(2). + */ + fd_cwd = open (sysroot, O_RDONLY | O_DIRECTORY); + if (fd_cwd == -1) { reply_with_perror ("%s", sysroot); return NULL; } @@ -93,7 +98,12 @@ do_case_sensitive_path (const char *path) /* Read the current directory looking (case insensitively) for * this element of the path. */ - DIR *dir = opendir ("."); + int fd2 = dup (fd_cwd); /* because closedir will close it */ + if (fd2 == -1) { + reply_with_perror ("dup"); + goto error; + } + DIR *dir = fdopendir (fd2); if (dir == NULL) { reply_with_perror ("opendir"); goto error; @@ -136,10 +146,15 @@ do_case_sensitive_path (const char *path) next += i; /* Is it a directory? Try going into it. */ - if (chdir (d->d_name) == -1) { + fd2 = openat (fd_cwd, d->d_name, O_RDONLY | O_DIRECTORY); + int err = errno; + close (fd_cwd); + fd_cwd = fd2; + errno = err; + if (fd_cwd == -1) { /* ENOTDIR is OK provided we've reached the end of the path. */ if (errno != ENOTDIR) { - reply_with_perror ("chdir: %s", d->d_name); + reply_with_perror ("openat: %s", d->d_name); goto error; } @@ -150,7 +165,7 @@ do_case_sensitive_path (const char *path) } } - ignore_value (chdir ("/")); + close (fd_cwd); ret[next] = '\0'; char *retp = strdup (ret); @@ -161,6 +176,6 @@ do_case_sensitive_path (const char *path) return retp; /* caller frees */ error: - ignore_value (chdir ("/")); + close (fd_cwd); return NULL; } |