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Diffstat (limited to 'src/bindfs.c')
-rw-r--r--src/bindfs.c269
1 files changed, 221 insertions, 48 deletions
diff --git a/src/bindfs.c b/src/bindfs.c
index 02f281c..24d4f53 100644
--- a/src/bindfs.c
+++ b/src/bindfs.c
@@ -64,6 +64,7 @@
#include "debug.h"
#include "permchain.h"
#include "userinfo.h"
+#include "usermap.h"
#include "misc.h"
/* SETTINGS */
@@ -77,6 +78,12 @@ static struct settings {
const char *mntsrc;
const char *mntdest;
int mntsrc_fd;
+
+ char* original_working_dir;
+ mode_t original_umask;
+
+ UserMap* usermap; /* From the --map option. */
+ UserMap* usermap_reverse;
enum CreatePolicy {
CREATE_AS_USER,
@@ -178,10 +185,13 @@ static int bindfs_fsync(const char *path, int isdatasync,
static void print_usage(const char *progname);
-static void atexit_func();
static int process_option(void *data, const char *arg, int key,
struct fuse_args *outargs);
static int parse_mirrored_users(char* mirror);
+static int parse_user_map(UserMap *map, UserMap *reverse_map, char *spec);
+static char* get_working_dir();
+static void maybe_stdout_stderr_to_file();
+static void atexit_func();
static int is_mirroring_enabled()
{
@@ -229,6 +239,10 @@ static int getattr_common(const char *procpath, struct stat *stbuf)
if (settings.ctime_from_mtime)
stbuf->st_ctime = stbuf->st_mtime;
+ /* Possibly map user/group */
+ stbuf->st_uid = usermap_get_uid(settings.usermap, stbuf->st_uid);
+ stbuf->st_gid = usermap_get_gid(settings.usermap, stbuf->st_gid);
+
/* Report user-defined owner/group if specified */
if (settings.new_uid != -1)
stbuf->st_uid = settings.new_uid;
@@ -243,26 +257,26 @@ static int getattr_common(const char *procpath, struct stat *stbuf)
return 0;
}
- if ((stbuf->st_mode & S_IFLNK) == S_IFLNK)
- return 0; /* don't bother with symlink permissions -- they don't matter */
-
- /* Apply user-defined permission bit modifications */
- stbuf->st_mode = permchain_apply(settings.permchain, stbuf->st_mode);
-
- /* Check that we can really do what we promise if --realistic-permissions was given */
- if (settings.realistic_permissions) {
- if (access(procpath, R_OK) == -1)
- stbuf->st_mode &= ~0444;
- if (access(procpath, W_OK) == -1)
- stbuf->st_mode &= ~0222;
- if (access(procpath, X_OK) == -1)
- stbuf->st_mode &= ~0111;
- }
-
/* Hide hard links */
if (settings.hide_hard_links)
stbuf->st_nlink = 1;
+ /* Then permission bits. Symlink permissions don't matter, though. */
+ if ((stbuf->st_mode & S_IFLNK) != S_IFLNK) {
+ /* Apply user-defined permission bit modifications */
+ stbuf->st_mode = permchain_apply(settings.permchain, stbuf->st_mode);
+
+ /* Check that we can really do what we promise if --realistic-permissions was given */
+ if (settings.realistic_permissions) {
+ if (access(procpath, R_OK) == -1)
+ stbuf->st_mode &= ~0444;
+ if (access(procpath, W_OK) == -1)
+ stbuf->st_mode &= ~0222;
+ if (access(procpath, X_OK) == -1)
+ stbuf->st_mode &= ~0111;
+ }
+ }
+
return 0;
}
@@ -270,6 +284,8 @@ static void *bindfs_init()
{
assert(settings.permchain != NULL);
assert(settings.mntsrc_fd > 0);
+
+ maybe_stdout_stderr_to_file();
if (fchdir(settings.mntsrc_fd) != 0) {
fprintf(
@@ -376,8 +392,8 @@ static int bindfs_mknod(const char *path, mode_t mode, dev_t rdev)
{
int res;
struct fuse_context *fc;
- uid_t file_owner = -1;
- gid_t file_group = -1;
+ uid_t file_owner;
+ gid_t file_group;
path = process_path(path);
@@ -390,11 +406,15 @@ static int bindfs_mknod(const char *path, mode_t mode, dev_t rdev)
if (res == -1)
return -errno;
+ fc = fuse_get_context();
+
if (settings.create_policy == CREATE_AS_USER) {
- fc = fuse_get_context();
file_owner = fc->uid;
file_group = fc->gid;
}
+
+ file_owner = usermap_get_uid_or_none(settings.usermap_reverse, fc->uid);
+ file_group = usermap_get_gid_or_none(settings.usermap_reverse, fc->gid);
if (settings.create_for_uid != -1)
file_owner = settings.create_for_uid;
@@ -414,8 +434,8 @@ static int bindfs_mkdir(const char *path, mode_t mode)
{
int res;
struct fuse_context *fc;
- uid_t file_owner = -1;
- gid_t file_group = -1;
+ uid_t file_owner;
+ gid_t file_group;
path = process_path(path);
@@ -426,11 +446,15 @@ static int bindfs_mkdir(const char *path, mode_t mode)
if (res == -1)
return -errno;
+ fc = fuse_get_context();
+
if (settings.create_policy == CREATE_AS_USER) {
- fc = fuse_get_context();
file_owner = fc->uid;
file_group = fc->gid;
}
+
+ file_owner = usermap_get_uid_or_none(settings.usermap_reverse, fc->uid);
+ file_group = usermap_get_gid_or_none(settings.usermap_reverse, fc->gid);
if (settings.create_for_uid != -1)
file_owner = settings.create_for_uid;
@@ -476,8 +500,8 @@ static int bindfs_symlink(const char *from, const char *to)
{
int res;
struct fuse_context *fc;
- uid_t file_owner = -1;
- gid_t file_group = -1;
+ uid_t file_owner;
+ gid_t file_group;
to = process_path(to);
@@ -485,11 +509,15 @@ static int bindfs_symlink(const char *from, const char *to)
if (res == -1)
return -errno;
+ fc = fuse_get_context();
+
if (settings.create_policy == CREATE_AS_USER) {
- fc = fuse_get_context();
file_owner = fc->uid;
file_group = fc->gid;
}
+
+ file_owner = usermap_get_uid_or_none(settings.usermap_reverse, fc->uid);
+ file_group = usermap_get_gid_or_none(settings.usermap_reverse, fc->gid);
if (settings.create_for_uid != -1)
file_owner = settings.create_for_uid;
@@ -661,8 +689,8 @@ static int bindfs_create(const char *path, mode_t mode, struct fuse_file_info *f
{
int fd;
struct fuse_context *fc;
- uid_t file_owner = -1;
- gid_t file_group = -1;
+ uid_t file_owner;
+ gid_t file_group;
path = process_path(path);
@@ -673,11 +701,15 @@ static int bindfs_create(const char *path, mode_t mode, struct fuse_file_info *f
if (fd == -1)
return -errno;
+ fc = fuse_get_context();
+
if (settings.create_policy == CREATE_AS_USER) {
- fc = fuse_get_context();
file_owner = fc->uid;
file_group = fc->gid;
}
+
+ file_owner = usermap_get_uid_or_none(settings.usermap_reverse, fc->uid);
+ file_group = usermap_get_gid_or_none(settings.usermap_reverse, fc->gid);
if (settings.create_for_uid != -1)
file_owner = settings.create_for_uid;
@@ -903,14 +935,14 @@ static void print_usage(const char *progname)
" -h --help Print this and exit.\n"
" -V --version Print version number and exit.\n"
"\n"
- "Options:\n"
+ "File ownership:\n"
" -u --user, --owner Set file owner.\n"
" -g --group Set file group.\n"
" -m --mirror Comma-separated list of users who will see\n"
" themselves as the owners of all files.\n"
" -M --mirror-only Like --mirror but disallow access for\n"
" all other users.\n"
- " -n --no-allow-other Do not add -o allow_other to fuse options.\n"
+ " --map=user1/user2:... Let user2 see files of user1 as his own.\n"
"\n"
"Permission bits:\n"
" -p --perms Specify permissions, similar to chmod\n"
@@ -945,6 +977,7 @@ static void print_usage(const char *progname)
" --xattr-rw Read-write xattr operations (the default).\n"
"\n"
"Miscellaneous:\n"
+ " -n --no-allow-other Do not add -o allow_other to fuse options.\n"
" --realistic-permissions Hide permission bits for actions mounter can't do.\n"
" --ctime-from-mtime Read file properties' change time\n"
" from file content modification time.\n"
@@ -963,18 +996,6 @@ static void print_usage(const char *progname)
}
-static void atexit_func()
-{
- permchain_destroy(settings.permchain);
- settings.permchain = NULL;
- permchain_destroy(settings.create_permchain);
- settings.create_permchain = NULL;
- free(settings.mirrored_users);
- settings.mirrored_users = NULL;
- free(settings.mirrored_members);
- settings.mirrored_members = NULL;
-}
-
enum OptionKey {
OPTKEY_NONOPTION = -2,
OPTKEY_UNKNOWN = -1,
@@ -1132,11 +1153,12 @@ static int parse_mirrored_users(char* mirror)
}
free(tmpstr);
- while (*p != '\0' && *p != ',' && *p != ':')
+ while (*p != '\0' && *p != ',' && *p != ':') {
++p;
- if (*p != '\0')
+ }
+ if (*p != '\0') {
++p;
- else {
+ } else {
/* Done. The counters should match. */
assert(i == settings.num_mirrored_users);
assert(j == settings.num_mirrored_members);
@@ -1146,6 +1168,144 @@ static int parse_mirrored_users(char* mirror)
return 1;
}
+static int parse_user_map(UserMap *map, UserMap *reverse_map, char *spec)
+{
+ char *p = spec;
+ char *tmpstr = NULL;
+ char *q;
+ uid_t uid_from, uid_to;
+ gid_t gid_from, gid_to;
+ UsermapStatus status;
+
+ while (*p != '\0') {
+ free(tmpstr);
+ tmpstr = strdup_until(p, ",:");
+
+ if (tmpstr[0] == '@') { /* group */
+ q = strstr(tmpstr, "/@");
+ if (!q) {
+ fprintf(stderr, "Invalid syntax: expected @group1/@group2 but got `%s`\n", tmpstr);
+ goto fail;
+ }
+ *q = '\0';
+ if (!group_gid(tmpstr + 1, &gid_from)) {
+ fprintf(stderr, "Invalid group: %s\n", tmpstr);
+ goto fail;
+ }
+ q += strlen("/@");
+ if (!group_gid(q, &gid_to)) {
+ fprintf(stderr, "Invalid group: %s\n", tmpstr);
+ goto fail;
+ }
+
+ status = usermap_add_gid(map, gid_from, gid_to);
+ if (status != 0) {
+ fprintf(stderr, "%s\n", usermap_errorstr(status));
+ goto fail;
+ }
+ status = usermap_add_gid(reverse_map, gid_to, gid_from);
+ if (status != 0) {
+ fprintf(stderr, "%s\n", usermap_errorstr(status));
+ goto fail;
+ }
+
+ } else {
+
+ q = strstr(tmpstr, "/");
+ if (!q) {
+ fprintf(stderr, "Invalid syntax: expected user1/user2 but got `%s`\n", tmpstr);
+ goto fail;
+ }
+ *q = '\0';
+ if (!user_uid(tmpstr, &uid_from)) {
+ fprintf(stderr, "Invalid username: %s\n", tmpstr);
+ goto fail;
+ }
+ q += strlen("/");
+ if (!user_uid(q, &uid_to)) {
+ fprintf(stderr, "Invalid username: %s\n", tmpstr);
+ goto fail;
+ }
+
+ status = usermap_add_uid(map, uid_from, uid_to);
+ if (status != 0) {
+ fprintf(stderr, "%s\n", usermap_errorstr(status));
+ goto fail;
+ }
+ status = usermap_add_uid(reverse_map, uid_to, uid_from);
+ if (status != 0) {
+ fprintf(stderr, "%s\n", usermap_errorstr(status));
+ goto fail;
+ }
+ }
+
+ while (*p != '\0' && *p != ',' && *p != ':') {
+ ++p;
+ }
+ if (*p != '\0') {
+ ++p;
+ }
+ }
+
+ free(tmpstr);
+ return 1;
+
+fail:
+ free(tmpstr);
+ return 0;
+}
+
+static void maybe_stdout_stderr_to_file()
+{
+ /* TODO: make this a command line option. */
+#if 0
+ int fd;
+
+ const char *filename = "bindfs.log";
+ char *path = malloc(strlen(settings.original_working_dir) + 1 + strlen(filename) + 1);
+ strcpy(path, settings.original_working_dir);
+ strcat(path, "/");
+ strcat(path, filename);
+
+ fd = open(path, O_CREAT | O_WRONLY);
+ free(path);
+
+ fchmod(fd, 0777 & ~settings.original_umask);
+ fflush(stdout);
+ fflush(stderr);
+ dup2(fd, 1);
+ dup2(fd, 2);
+#endif
+}
+
+static char* get_working_dir()
+{
+ size_t buf_size = 4096;
+ char* buf = malloc(buf_size);
+ while (!getcwd(buf, buf_size)) {
+ buf_size *= 2;
+ buf = realloc(buf, buf_size);
+ }
+ return buf;
+}
+
+static void atexit_func()
+{
+ free(settings.original_working_dir);
+ settings.original_working_dir = NULL;
+ usermap_destroy(settings.usermap);
+ settings.usermap = NULL;
+ usermap_destroy(settings.usermap_reverse);
+ settings.usermap_reverse = NULL;
+ permchain_destroy(settings.permchain);
+ settings.permchain = NULL;
+ permchain_destroy(settings.create_permchain);
+ settings.create_permchain = NULL;
+ free(settings.mirrored_users);
+ settings.mirrored_users = NULL;
+ free(settings.mirrored_members);
+ settings.mirrored_members = NULL;
+}
int main(int argc, char *argv[])
{
@@ -1158,6 +1318,7 @@ int main(int argc, char *argv[])
char *perms;
char *mirror;
char *mirror_only;
+ char *map;
char *create_for_user;
char *create_for_group;
char *create_with_perms;
@@ -1183,6 +1344,7 @@ int main(int argc, char *argv[])
OPT_OFFSET3("-p %s", "--perms=%s", "perms=%s", perms, -1),
OPT_OFFSET3("-m %s", "--mirror=%s", "mirror=%s", mirror, -1),
OPT_OFFSET3("-M %s", "--mirror-only=%s", "mirror-only=%s", mirror_only, -1),
+ OPT_OFFSET2("--map=%s", "map=%s", map, -1),
OPT_OFFSET3("-n", "--no-allow-other", "no-allow-other", no_allow_other, -1),
OPT2("--create-as-user", "create-as-user", OPTKEY_CREATE_AS_USER),
OPT2("--create-as-mounter", "create-as-mounter", OPTKEY_CREATE_AS_MOUNTER),
@@ -1215,12 +1377,15 @@ int main(int argc, char *argv[])
memset(&od, 0, sizeof(od));
settings.progname = argv[0];
settings.permchain = permchain_create();
+ settings.usermap = usermap_create();
+ settings.usermap_reverse = usermap_create();
settings.new_uid = -1;
settings.new_gid = -1;
settings.create_for_uid = -1;
settings.create_for_gid = -1;
settings.mntsrc = NULL;
settings.mntdest = NULL;
+ settings.original_working_dir = get_working_dir();
settings.create_policy = (getuid() == 0) ? CREATE_AS_USER : CREATE_AS_MOUNTER;
settings.create_permchain = permchain_create();
settings.chown_policy = CHOWN_NORMAL;
@@ -1237,7 +1402,7 @@ int main(int argc, char *argv[])
settings.ctime_from_mtime = 0;
settings.hide_hard_links = 0;
atexit(&atexit_func);
-
+
/* Parse options */
if (fuse_opt_parse(&args, &od, options, &process_option) == -1)
return 1;
@@ -1261,6 +1426,14 @@ int main(int argc, char *argv[])
return 1;
}
}
+
+ /* Parse usermap */
+ if (od.map) {
+ if (!parse_user_map(settings.usermap, settings.usermap_reverse, od.map)) {
+ /* parse_user_map printed an error */
+ return 1;
+ }
+ }
/* Parse user and group for new creates */
if (od.create_for_user) {
@@ -1341,7 +1514,7 @@ int main(int argc, char *argv[])
}
/* Ignore the umask of the mounter on file creation */
- umask(0);
+ settings.original_umask = umask(0);
/* Remove xattr implementation if the user doesn't want it */
if (settings.xattr_policy == XATTR_UNIMPLEMENTED) {
generated by cgit v1.2.3 (git 2.39.1) at 2025-10-07 20:25:11 +0000