1 /* This program can record the stream of data flowing to or from a program.
2 * This allows it to be used to check that rsync's data that is flowing
3 * through a remote shell is not being corrupted (for example).
5 * Usage: savetransfer [-i|-o] OUTPUT_FILE PROGRAM [ARGS...]
6 * -i Save the input going to PROGRAM to the OUTPUT_FILE
7 * -o Save the output coming from PROGRAM to the OUTPUT_FILE
9 * If you want to capture the flow of data for an rsync command, use one of
10 * the following commands (the first two are push commands, the last two are
13 * rsync -av --rsh="savetransfer -i /tmp/from.sender ssh"
14 * --rsync-path="savetransfer -i /tmp/to.receiver rsync" FILES HOST:DEST
16 * rsync -av --rsh="savetransfer -o /tmp/to.sender ssh"
17 * --rsync-path="savetransfer -o /tmp/from.generator rsync" FILES HOST:DEST
19 * rsync -av --rsh="savetransfer -i /tmp/from.generator ssh"
20 * --rsync-path="savetransfer -i /tmp/to.sender rsync" HOST:FILES DEST
22 * rsync -av --rsh="savetransfer -o /tmp/to.receiver ssh"
23 * --rsync-path="savetransfer -o /tmp/from.sender rsync" HOST:FILES DEST
25 * Note that this program aborts after 30 seconds of inactivity, so you'll need
26 * to change it if that is not enough dead time for your transfer. Also, some
27 * of the above commands will not notice that the transfer is done (if we're
28 * saving the input to a PROGRAM and the PROGRAM goes away: we won't notice
29 * that it's gone unless more data comes in) -- when this happens it will delay
30 * at the end of the transfer until the timeout period expires.
35 #define TIMEOUT_SECONDS 30
37 void run_program(char **command);
40 int save_data_from_program = 0;
43 main(int argc, char *argv[])
50 if (--argc && argv[0][0] == '-') {
51 if (argv[0][1] == 'o')
52 save_data_from_program = 1;
53 else if (argv[0][1] == 'i')
54 save_data_from_program = 0;
56 fprintf(stderr, "Unknown option: %s\n", argv[0]);
63 fprintf(stderr, "Usage: savetransfer [-i|-o] OUTPUT_FILE PROGRAM [ARGS...]\n");
64 fprintf(stderr, "-i Save the input going to PROGRAM to the OUTPUT_FILE\n");
65 fprintf(stderr, "-o Save the output coming from PROGRAM to the OUTPUT_FILE\n");
68 if ((fd_file = open(*argv, O_WRONLY|O_TRUNC|O_CREAT|O_BINARY, 0644)) < 0) {
69 fprintf(stderr, "Unable to write to `%s': %s\n", *argv, strerror(errno));
72 set_blocking(fd_file);
74 signal(SIGPIPE, SIG_IGN);
76 run_program(argv + 1);
78 #if HAVE_SETMODE && O_BINARY
79 setmode(STDIN_FILENO, O_BINARY);
80 setmode(STDOUT_FILENO, O_BINARY);
82 set_nonblocking(STDIN_FILENO);
83 set_blocking(STDOUT_FILENO);
87 FD_SET(STDIN_FILENO, &fds);
88 tv.tv_sec = TIMEOUT_SECONDS;
90 if (!select(STDIN_FILENO+1, &fds, NULL, NULL, &tv))
92 if (!FD_ISSET(STDIN_FILENO, &fds))
94 if ((len = read(STDIN_FILENO, buf, sizeof buf)) <= 0)
96 if (write(STDOUT_FILENO, buf, len) != len) {
97 fprintf(stderr, "Failed to write data to stdout: %s\n", strerror(errno));
100 if (write(fd_file, buf, len) != len) {
101 fprintf(stderr, "Failed to write data to fd_file: %s\n", strerror(errno));
109 run_program(char **command)
111 int pipe_fds[2], ret;
114 if (pipe(pipe_fds) < 0) {
115 fprintf(stderr, "pipe failed: %s\n", strerror(errno));
119 if ((pid = fork()) < 0) {
120 fprintf(stderr, "fork failed: %s\n", strerror(errno));
125 if (save_data_from_program)
126 ret = dup2(pipe_fds[1], STDOUT_FILENO);
128 ret = dup2(pipe_fds[0], STDIN_FILENO);
130 fprintf(stderr, "Failed to dup (in child): %s\n", strerror(errno));
135 set_blocking(STDIN_FILENO);
136 set_blocking(STDOUT_FILENO);
137 execvp(command[0], command);
138 fprintf(stderr, "Failed to exec %s: %s\n", command[0], strerror(errno));
142 if (save_data_from_program)
143 ret = dup2(pipe_fds[0], STDIN_FILENO);
145 ret = dup2(pipe_fds[1], STDOUT_FILENO);
147 fprintf(stderr, "Failed to dup (in parent): %s\n", strerror(errno));
155 set_nonblocking(int fd)
159 if ((val = fcntl(fd, F_GETFL, 0)) == -1)
161 if (!(val & NONBLOCK_FLAG)) {
162 val |= NONBLOCK_FLAG;
163 fcntl(fd, F_SETFL, val);
172 if ((val = fcntl(fd, F_GETFL, 0)) < 0)
174 if (val & NONBLOCK_FLAG) {
175 val &= ~NONBLOCK_FLAG;
176 fcntl(fd, F_SETFL, val);