diff options
Diffstat (limited to 'support/savetransfer.c')
| -rw-r--r-- | support/savetransfer.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/support/savetransfer.c b/support/savetransfer.c new file mode 100644 index 0000000..808a6f2 --- /dev/null +++ b/support/savetransfer.c @@ -0,0 +1,175 @@ +/* This program can record the stream of data flowing to or from a program. + * This allows it to be used to check that rsync's data that is flowing + * through a remote shell is not being corrupted (for example). + * + * Usage: savetransfer [-i|-o] OUTPUT_FILE PROGRAM [ARGS...] + * -i Save the input going to PROGRAM to the OUTPUT_FILE + * -o Save the output coming from PROGRAM to the OUTPUT_FILE + * + * If you want to capture the flow of data for an rsync command, use one of + * the following commands (the resulting files should be identical): + * + * rsync -av --rsh="savetransfer -i /tmp/to.server ssh" + * --rsync-path="savetransfer -i /tmp/from.client rsync" SOURCE DEST + * + * rsync -av --rsh="savetransfer -o /tmp/from.server ssh" + * --rsync-path="savetransfer -o /tmp/to.client rsync" SOURCE DEST + * + * Note that this program aborts after 30 seconds of inactivity, so you'll need + * to change it if that is not enough dead time for your transfer. Also, some + * of the above commands will not notice that the transfer is done (if we're + * saving the input to a PROGRAM and the PROGRAM goes away: we won't notice + * that it's gone unless more data comes in) -- when this happens it will delay + * at the end of the transfer until the timeout period expires. + */ + +#include "../rsync.h" + +#define TIMEOUT_SECONDS 30 + +#ifdef HAVE_SIGACTION +static struct sigaction sigact; +#endif + +void run_program(char **command); + +char buf[4096]; +int save_data_from_program = 0; + +int +main(int argc, char *argv[]) +{ + int fd_file, len; + struct timeval tv; + fd_set fds; + + argv++; + if (--argc && argv[0][0] == '-') { + if (argv[0][1] == 'o') + save_data_from_program = 1; + else if (argv[0][1] == 'i') + save_data_from_program = 0; + else { + fprintf(stderr, "Unknown option: %s\n", argv[0]); + exit(1); + } + argv++; + argc--; + } + if (argc < 2) { + fprintf(stderr, "Usage: savetransfer [-i|-o] OUTPUT_FILE PROGRAM [ARGS...]\n"); + fprintf(stderr, "-i Save the input going to PROGRAM to the OUTPUT_FILE\n"); + fprintf(stderr, "-o Save the output coming from PROGRAM to the OUTPUT_FILE\n"); + exit(1); + } + if ((fd_file = open(*argv, O_WRONLY|O_TRUNC|O_CREAT|O_BINARY, 0644)) < 0) { + fprintf(stderr, "Unable to write to `%s': %s\n", *argv, strerror(errno)); + exit(1); + } + set_blocking(fd_file); + + SIGACTION(SIGPIPE, SIG_IGN); + + run_program(argv + 1); + +#if defined HAVE_SETMODE && O_BINARY + setmode(STDIN_FILENO, O_BINARY); + setmode(STDOUT_FILENO, O_BINARY); +#endif + set_nonblocking(STDIN_FILENO); + set_blocking(STDOUT_FILENO); + + while (1) { + FD_ZERO(&fds); + FD_SET(STDIN_FILENO, &fds); + tv.tv_sec = TIMEOUT_SECONDS; + tv.tv_usec = 0; + if (!select(STDIN_FILENO+1, &fds, NULL, NULL, &tv)) + break; + if (!FD_ISSET(STDIN_FILENO, &fds)) + break; + if ((len = read(STDIN_FILENO, buf, sizeof buf)) <= 0) + break; + if (write(STDOUT_FILENO, buf, len) != len) { + fprintf(stderr, "Failed to write data to stdout: %s\n", strerror(errno)); + exit(1); + } + if (write(fd_file, buf, len) != len) { + fprintf(stderr, "Failed to write data to fd_file: %s\n", strerror(errno)); + exit(1); + } + } + return 0; +} + +void +run_program(char **command) +{ + int pipe_fds[2], ret; + pid_t pid; + + if (pipe(pipe_fds) < 0) { + fprintf(stderr, "pipe failed: %s\n", strerror(errno)); + exit(1); + } + + if ((pid = fork()) < 0) { + fprintf(stderr, "fork failed: %s\n", strerror(errno)); + exit(1); + } + + if (pid == 0) { + if (save_data_from_program) + ret = dup2(pipe_fds[1], STDOUT_FILENO); + else + ret = dup2(pipe_fds[0], STDIN_FILENO); + if (ret < 0) { + fprintf(stderr, "Failed to dup (in child): %s\n", strerror(errno)); + exit(1); + } + close(pipe_fds[0]); + close(pipe_fds[1]); + set_blocking(STDIN_FILENO); + set_blocking(STDOUT_FILENO); + execvp(command[0], command); + fprintf(stderr, "Failed to exec %s: %s\n", command[0], strerror(errno)); + exit(1); + } + + if (save_data_from_program) + ret = dup2(pipe_fds[0], STDIN_FILENO); + else + ret = dup2(pipe_fds[1], STDOUT_FILENO); + if (ret < 0) { + fprintf(stderr, "Failed to dup (in parent): %s\n", strerror(errno)); + exit(1); + } + close(pipe_fds[0]); + close(pipe_fds[1]); +} + +void +set_nonblocking(int fd) +{ + int val; + + if ((val = fcntl(fd, F_GETFL, 0)) == -1) + return; + if (!(val & NONBLOCK_FLAG)) { + val |= NONBLOCK_FLAG; + fcntl(fd, F_SETFL, val); + } +} + +void +set_blocking(int fd) +{ + int val; + + if ((val = fcntl(fd, F_GETFL, 0)) < 0) + return; + if (val & NONBLOCK_FLAG) { + val &= ~NONBLOCK_FLAG; + fcntl(fd, F_SETFL, val); + } +} |