From d1238ce060fca3e5cb7cc85306ac8103d1a20131 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?= Date: Tue, 3 Nov 2015 03:42:49 +0100 Subject: [PATCH] qrexec-lib: add qfile packing functions to libqubes-rpc-filecopy This is counterpart of 5774c78 "qfile-agent: move data handling code to libqubes-rpc-filecopy" in core-agent-linux. The main purpose is to easily reuse the code in dom0 qvm-copy-to-vm tool. QubesOS/qubes-issues#1324 --- qrexec-lib/Makefile | 2 +- qrexec-lib/libqubes-rpc-filecopy.h | 23 ++- qrexec-lib/pack.c | 229 +++++++++++++++++++++++++++++ 3 files changed, 252 insertions(+), 2 deletions(-) create mode 100644 qrexec-lib/pack.c diff --git a/qrexec-lib/Makefile b/qrexec-lib/Makefile index d7cde6c..d2f461a 100644 --- a/qrexec-lib/Makefile +++ b/qrexec-lib/Makefile @@ -14,7 +14,7 @@ endif all: libqrexec-utils.so.$(SO_VER) libqubes-rpc-filecopy.so.$(SO_VER) libqrexec-utils.so.$(SO_VER): unix-server.o ioall.o buffer.o exec.o txrx-vchan.o write-stdin.o $(CC) $(LDFLAGS) -Wl,-soname,$@ -o $@ $^ $(VCHANLIBS) -libqubes-rpc-filecopy.so.$(SO_VER): ioall.o copy-file.o crc32.o unpack.o +libqubes-rpc-filecopy.so.$(SO_VER): ioall.o copy-file.o crc32.o unpack.o pack.o $(CC) $(LDFLAGS) -Wl,-soname,$@ -o $@ $^ %.a: diff --git a/qrexec-lib/libqubes-rpc-filecopy.h b/qrexec-lib/libqubes-rpc-filecopy.h index 6cc9d79..1fbaaf8 100644 --- a/qrexec-lib/libqubes-rpc-filecopy.h +++ b/qrexec-lib/libqubes-rpc-filecopy.h @@ -30,6 +30,9 @@ #define LEGAL_EOF 31415926 #include +#include +#include +#include struct file_header { unsigned int namelen; @@ -60,8 +63,13 @@ enum { COPY_FILE_WRITE_ERROR }; +/* feedback handling */ typedef void (notify_progress_t)(int, int); +typedef void (error_handler_t)(const char *fmt, va_list args); void register_notify_progress(notify_progress_t *func); +void register_error_handler(error_handler_t *func); + +/* common functions */ int copy_file(int outfd, int infd, long long size, unsigned long *crc32); const char *copy_file_status_to_str(int status); void set_size_limit(unsigned long long new_bytes_limit, unsigned long long new_files_limit); @@ -74,9 +82,22 @@ int copy_fd_all(int fdout, int fdin); void set_nonblock(int fd); void set_block(int fd); +/* unpacking */ extern unsigned long Crc32_ComputeBuf( unsigned long inCrc32, const void *buf, size_t bufLen ); - extern int do_unpack(void); +/* packing */ +int single_file_processor(const char *filename, const struct stat *st); +int do_fs_walk(const char *file, int ignore_symlinks); +/* used in tar2qfile to alter only headers, but keep original file stream */ +void write_headers(const struct file_header *hdr, const char *filename); +int copy_file_with_crc(int outfd, int infd, long long size); +/* MUST be called before first do_fs_walk/single_file_processor */ +void qfile_pack_init(void); +void set_ignore_quota_error(int value); +/* those two will call registered error handler if needed */ +void wait_for_result(void); +void notify_end_and_wait_for_result(void); + #endif /* _LIBQUBES_RPC_FILECOPY_H */ diff --git a/qrexec-lib/pack.c b/qrexec-lib/pack.c new file mode 100644 index 0000000..2a30f45 --- /dev/null +++ b/qrexec-lib/pack.c @@ -0,0 +1,229 @@ +#define _GNU_SOURCE /* See feature_test_macros(7) */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "libqubes-rpc-filecopy.h" + +static unsigned long crc32_sum; +static int ignore_quota_error = 0; +error_handler_t *error_handler = NULL; + +void register_error_handler(error_handler_t *value) { + error_handler = value; +} + +_Noreturn static void call_error_handler(const char *fmt, ...) +{ + va_list args; + va_start(args, fmt); + if (error_handler) { + error_handler(fmt, args); + } else { + vfprintf(stderr, fmt, args); + } + va_end(args); + exit(1); +} + +static int write_all_with_crc(int fd, const void *buf, int size) +{ + crc32_sum = Crc32_ComputeBuf(crc32_sum, buf, size); + return write_all(fd, buf, size); +} + +void notify_end_and_wait_for_result(void) +{ + struct file_header end_hdr; + + /* nofity end of transfer */ + memset(&end_hdr, 0, sizeof(end_hdr)); + end_hdr.namelen = 0; + end_hdr.filelen = 0; + write_all_with_crc(1, &end_hdr, sizeof(end_hdr)); + + set_block(0); + wait_for_result(); +} + +void wait_for_result(void) +{ + struct result_header hdr; + struct result_header_ext hdr_ext; + char last_filename[MAX_PATH_LENGTH + 1]; + char last_filename_prefix[] = "; Last file: "; + + if (!read_all(0, &hdr, sizeof(hdr))) { + if (errno == EAGAIN) { + // no result sent and stdin still open + return; + } else { + // other read error or EOF + exit(1); // hopefully remote has produced error message + } + } + if (!read_all(0, &hdr_ext, sizeof(hdr_ext))) { + // remote used old result_header struct + hdr_ext.last_namelen = 0; + } + if (hdr_ext.last_namelen > MAX_PATH_LENGTH) { + // read only at most MAX_PATH_LENGTH chars + hdr_ext.last_namelen = MAX_PATH_LENGTH; + } + if (!read_all(0, last_filename, hdr_ext.last_namelen)) { + fprintf(stderr, "Failed to get last filename\n"); + hdr_ext.last_namelen = 0; + } + last_filename[hdr_ext.last_namelen] = '\0'; + if (!hdr_ext.last_namelen) + /* set prefix to empty string */ + last_filename_prefix[0] = '\0'; + + errno = hdr.error_code; + if (hdr.error_code != 0) { + switch (hdr.error_code) { + case EEXIST: + call_error_handler("File copy: not overwriting existing file. Clean QubesIncoming dir, and retry copy%s%s", last_filename_prefix, last_filename); + break; + case EINVAL: + call_error_handler("File copy: Corrupted data from packer%s%s", last_filename_prefix, last_filename); + break; + case EDQUOT: + if (ignore_quota_error) { + /* skip also CRC check as sender and receiver might be + * desynchronized in this case */ + return; + } + /* fall though */ + default: + call_error_handler("File copy: %s%s%s", + strerror(hdr.error_code), last_filename_prefix, last_filename); + } + } + if (hdr.crc32 != crc32_sum) { + call_error_handler("File transfer failed: checksum mismatch"); + } +} + +void write_headers(const struct file_header *hdr, const char *filename) +{ + if (!write_all_with_crc(1, hdr, sizeof(*hdr)) + || !write_all_with_crc(1, filename, hdr->namelen)) { + set_block(0); + wait_for_result(); + exit(1); + } +} + +int copy_file_with_crc(int outfd, int infd, long long size) { + return copy_file(outfd, infd, size, &crc32_sum); +} + +int single_file_processor(const char *filename, const struct stat *st) +{ + struct file_header hdr; + int fd; + mode_t mode = st->st_mode; + + hdr.namelen = strlen(filename) + 1; + hdr.mode = mode; + hdr.atime = st->st_atim.tv_sec; + hdr.atime_nsec = st->st_atim.tv_nsec; + hdr.mtime = st->st_mtim.tv_sec; + hdr.mtime_nsec = st->st_mtim.tv_nsec; + + if (S_ISREG(mode)) { + int ret; + fd = open(filename, O_RDONLY); + if (fd < 0) + call_error_handler("open %s", filename); + hdr.filelen = st->st_size; + write_headers(&hdr, filename); + ret = copy_file(1, fd, hdr.filelen, &crc32_sum); + if (ret != COPY_FILE_OK) { + if (ret != COPY_FILE_WRITE_ERROR) + call_error_handler("Copying file %s: %s", filename, + copy_file_status_to_str(ret)); + else { + set_block(0); + wait_for_result(); + exit(1); + } + } + close(fd); + } + if (S_ISDIR(mode)) { + hdr.filelen = 0; + write_headers(&hdr, filename); + } + if (S_ISLNK(mode)) { + char name[st->st_size + 1]; + if (readlink(filename, name, sizeof(name)) != st->st_size) + call_error_handler("readlink %s", filename); + hdr.filelen = st->st_size; + write_headers(&hdr, filename); + if (!write_all_with_crc(1, name, st->st_size)) { + set_block(0); + wait_for_result(); + exit(1); + } + } + // check for possible error from qfile-unpacker + wait_for_result(); + return 0; +} + +int do_fs_walk(const char *file, int ignore_symlinks) +{ + char *newfile; + struct stat st; + struct dirent *ent; + DIR *dir; + + if (lstat(file, &st)) + call_error_handler("stat %s", file); + if (S_ISLNK(st.st_mode) && ignore_symlinks) + return 0; + single_file_processor(file, &st); + if (!S_ISDIR(st.st_mode)) + return 0; + dir = opendir(file); + if (!dir) + call_error_handler("opendir %s", file); + while ((ent = readdir(dir))) { + char *fname = ent->d_name; + if (!strcmp(fname, ".") || !strcmp(fname, "..")) + continue; + if (asprintf(&newfile, "%s/%s", file, fname) >= 0) { + do_fs_walk(newfile, ignore_symlinks); + free(newfile); + } else { + fprintf(stderr, "asprintf failed\n"); + exit(1); + } + } + closedir(dir); + // directory metadata is resent; this makes the code simple, + // and the atime/mtime is set correctly at the second time + single_file_processor(file, &st); + return 0; +} + +void qfile_pack_init(void) { + crc32_sum = 0; + ignore_quota_error = 0; + // this will allow checking for possible feedback packet in the middle of transfer + set_nonblock(0); + signal(SIGPIPE, SIG_IGN); + error_handler = NULL; +} + +void set_ignore_quota_error(int value) { + ignore_quota_error = value; +}