diff options
Diffstat (limited to 'src/user/fs/misc.c')
| -rw-r--r-- | src/user/fs/misc.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/src/user/fs/misc.c b/src/user/fs/misc.c new file mode 100644 index 0000000..bf09718 --- /dev/null +++ b/src/user/fs/misc.c @@ -0,0 +1,168 @@ +#include <user/fs/misc.h> +#include <user/lib/stdlib.h> +#include <shared/flags.h> +#include <shared/mem.h> +#include <shared/syscalls.h> +#include <stdbool.h> + +bool fork2_n_mount(const char *path) { + handle_t h; + if (_syscall_fork(FORK_NEWFS, &h) > 0) { /* parent */ + _syscall_mount(h, path, strlen(path)); + _syscall_close(h); + return true; + } + return false; +} + +void fs_passthru(const char *prefix) { + struct fs_wait_response res; + const size_t buf_len = 1024; + char *buf = malloc(buf_len); + int prefix_len = prefix ? strlen(prefix) : 0; + if (!buf) _syscall_exit(1); + + while (!_syscall_fs_wait(buf, buf_len, &res)) { + switch (res.op) { + case VFSOP_OPEN: + if (prefix) { + if (prefix_len + res.len > buf_len) { + _syscall_fs_respond(NULL, -1, 0); + break; + } + + // TODO memmove + char tmp[64]; + memcpy(tmp, buf, res.len); + memcpy(buf + prefix_len, tmp, res.len); + memcpy(buf, prefix, prefix_len); + res.len += prefix_len; + } + _syscall_fs_respond(NULL, _syscall_open(buf, res.len, res.flags), FSR_DELEGATE); + break; + + default: + _syscall_fs_respond(NULL, -1, 0); + break; + } + } + _syscall_exit(0); +} + +void fs_whitelist(const char **list) { + struct fs_wait_response res; + const size_t buf_len = 1024; + char *buf = malloc(buf_len); + bool allow; + if (!buf) _syscall_exit(1); + + while (!_syscall_fs_wait(buf, buf_len, &res)) { + switch (res.op) { + case VFSOP_OPEN: + allow = false; + // TODO reverse dir_inject + for (const char **iter = list; *iter; iter++) { + size_t len = strlen(*iter); // inefficient, whatever + if (len <= res.len && !memcmp(buf, *iter, len)) { + allow = true; + break; + } + } + _syscall_fs_respond(NULL, allow ? _syscall_open(buf, res.len, res.flags) : -1, FSR_DELEGATE); + break; + + default: + _syscall_fs_respond(NULL, -1, 0); + break; + } + } + _syscall_exit(0); +} + + +void fs_dir_inject(const char *path) { + struct fs_dir_handle { + const char *inject; + int delegate, inject_len; + }; + + const size_t path_len = strlen(path); + struct fs_wait_response res; + struct fs_dir_handle *data; + const size_t buf_len = 1024; + char *buf = malloc(buf_len); + int ret, inject_len; + + if (!buf) _syscall_exit(1); + + while (!_syscall_fs_wait(buf, buf_len, &res)) { + data = res.id; + switch (res.op) { + case VFSOP_OPEN: + if (buf[res.len - 1] == '/' && + res.len < path_len && !memcmp(path, buf, res.len)) + { + /* opening a directory that we're injecting into */ + + if (res.flags & OPEN_CREATE) { + _syscall_fs_respond(NULL, -1, 0); + break; + } + + data = malloc(sizeof *data); + data->delegate = _syscall_open(buf, res.len, res.flags); + data->inject = path + res.len; + + /* inject up to the next slash */ + inject_len = 0; + while (data->inject[inject_len] && data->inject[inject_len] != '/') + inject_len++; + if (data->inject[inject_len] == '/') + inject_len++; + data->inject_len = inject_len; + + _syscall_fs_respond(data, 0, 0); + } else { + _syscall_fs_respond(NULL, _syscall_open(buf, res.len, res.flags), FSR_DELEGATE); + } + break; + + case VFSOP_CLOSE: + if (data->delegate >= 0) + _syscall_close(data->delegate); + _syscall_fs_respond(NULL, 0, 0); + break; + + case VFSOP_READ: + if (res.offset > 0) _syscall_fs_respond(NULL, 0, 0); // TODO working offsets + + int out_len = data->inject_len; + memcpy(buf, data->inject, out_len); + buf[out_len++] = '\0'; + + if (data->delegate >= 0) { + int to_read = res.capacity < buf_len ? res.capacity : buf_len; + to_read -= out_len; + ret = _syscall_read(data->delegate, buf + out_len, to_read, 0); + if (ret > 0) out_len += ret; + // TODO deduplicate entries + } + + _syscall_fs_respond(buf, out_len, 0); + break; + + case VFSOP_WRITE: + if (data->delegate >= 0) + ret = _syscall_write(data->delegate, buf, res.len, res.offset); + else + ret = -1; + _syscall_fs_respond(NULL, ret, 0); + break; + + default: + _syscall_fs_respond(NULL, -1, 0); + break; + } + } + _syscall_exit(0); +} |