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Diffstat (limited to 'src/util/make_dirs.c')
| -rw-r--r-- | src/util/make_dirs.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/src/util/make_dirs.c b/src/util/make_dirs.c new file mode 100644 index 0000000..2e37f8f --- /dev/null +++ b/src/util/make_dirs.c @@ -0,0 +1,173 @@ +/*++ +/* NAME +/* make_dirs 3 +/* SUMMARY +/* create directory hierarchy +/* SYNOPSIS +/* #include <make_dirs.h> +/* +/* int make_dirs(path, perms) +/* const char *path; +/* int perms; +/* DESCRIPTION +/* make_dirs() creates the directory specified in \fIpath\fR, and +/* creates any missing intermediate directories as well. Directories +/* are created with the permissions specified in \fIperms\fR, as +/* modified by the process umask. +/* DIAGNOSTICS: +/* Fatal: out of memory. make_dirs() returns 0 in case of success. +/* In case of problems. make_dirs() returns -1 and \fIerrno\fR +/* reflects the nature of the problem. +/* SEE ALSO +/* mkdir(2) +/* LICENSE +/* .ad +/* .fi +/* The Secure Mailer license must be distributed with this software. +/* AUTHOR(S) +/* Wietse Venema +/* IBM T.J. Watson Research +/* P.O. Box 704 +/* Yorktown Heights, NY 10598, USA +/*--*/ + +/* System library. */ + +#include <sys_defs.h> +#include <sys/stat.h> +#include <errno.h> +#include <string.h> +#include <unistd.h> + +/* Utility library. */ + +#include "msg.h" +#include "mymalloc.h" +#include "stringops.h" +#include "make_dirs.h" +#include "warn_stat.h" + +/* make_dirs - create directory hierarchy */ + +int make_dirs(const char *path, int perms) +{ + const char *myname = "make_dirs"; + char *saved_path; + unsigned char *cp; + int saved_ch; + struct stat st; + int ret; + mode_t saved_mode = 0; + gid_t egid = -1; + + /* + * Initialize. Make a copy of the path that we can safely clobber. + */ + cp = (unsigned char *) (saved_path = mystrdup(path)); + + /* + * I didn't like the 4.4BSD "mkdir -p" implementation, but coming up with + * my own took a day, spread out over several days. + */ +#define SKIP_WHILE(cond, ptr) { while(*ptr && (cond)) ptr++; } + + SKIP_WHILE(*cp == '/', cp); + + for (;;) { + SKIP_WHILE(*cp != '/', cp); + if ((saved_ch = *cp) != 0) + *cp = 0; + if ((ret = stat(saved_path, &st)) >= 0) { + if (!S_ISDIR(st.st_mode)) { + errno = ENOTDIR; + ret = -1; + break; + } + saved_mode = st.st_mode; + } else { + if (errno != ENOENT) + break; + + /* + * mkdir(foo) fails with EEXIST if foo is a symlink. + */ +#if 0 + + /* + * Create a new directory. Unfortunately, mkdir(2) has no + * equivalent of open(2)'s O_CREAT|O_EXCL safety net, so we must + * require that the parent directory is not world writable. + * Detecting a lost race condition after the fact is not + * sufficient, as an attacker could repeat the attack and add one + * directory level at a time. + */ + if (saved_mode & S_IWOTH) { + msg_warn("refusing to mkdir %s: parent directory is writable by everyone", + saved_path); + errno = EPERM; + ret = -1; + break; + } +#endif + if ((ret = mkdir(saved_path, perms)) < 0) { + if (errno != EEXIST) + break; + /* Race condition? */ + if ((ret = stat(saved_path, &st)) < 0) + break; + if (!S_ISDIR(st.st_mode)) { + errno = ENOTDIR; + ret = -1; + break; + } + } + + /* + * Fix directory ownership when mkdir() ignores the effective + * GID. Don't change the effective UID for doing this. + */ + if ((ret = stat(saved_path, &st)) < 0) { + msg_warn("%s: stat %s: %m", myname, saved_path); + break; + } + if (egid == -1) + egid = getegid(); + if (st.st_gid != egid && (ret = chown(saved_path, -1, egid)) < 0) { + msg_warn("%s: chgrp %s: %m", myname, saved_path); + break; + } + } + if (saved_ch != 0) + *cp = saved_ch; + SKIP_WHILE(*cp == '/', cp); + if (*cp == 0) + break; + } + + /* + * Cleanup. + */ + myfree(saved_path); + return (ret); +} + +#ifdef TEST + + /* + * Test program. Usage: make_dirs path... + */ +#include <stdlib.h> +#include <msg_vstream.h> + +int main(int argc, char **argv) +{ + msg_vstream_init(argv[0], VSTREAM_ERR); + if (argc < 2) + msg_fatal("usage: %s path...", argv[0]); + while (--argc > 0 && *++argv != 0) + if (make_dirs(*argv, 0755)) + msg_fatal("%s: %m", *argv); + exit(0); +} + +#endif |