diff options
Diffstat (limited to 'hdlcgen.c')
-rw-r--r-- | hdlcgen.c | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/hdlcgen.c b/hdlcgen.c new file mode 100644 index 0000000..417004b --- /dev/null +++ b/hdlcgen.c @@ -0,0 +1,105 @@ +#define FAST_HDLC_NEED_TABLES +#include "kernel/fasthdlc.h" +#include <stdio.h> +#include <fcntl.h> +#include <string.h> +#include <errno.h> +#include <unistd.h> +#include <stdlib.h> + +#define RANDOM "/dev/urandom" /* Not genuinely random */ +/* #define RANDOM "/dev/random" */ /* Quite genuinely random */ + +int myread(int fd, char *buf, int len) +{ + int sofar; + int res; + sofar = 0; + while(sofar < len) { + res = read(fd, buf + sofar, len - sofar); + if (res < 0) + return res; + sofar += res; + } + return sofar; +} + +int main(int argc, char *argv[]) +{ + unsigned char buf[1024]; + unsigned char outbuf[2048]; + int res; + int randin; + int randout; + int hdlcout; + int cnt; + int hdlccnt; + int x; + int flags; + struct fasthdlc_state transmitter; + + fasthdlc_precalc(); + + fasthdlc_init(&transmitter); + + randin = open(RANDOM, O_RDONLY); + if (randin < 0) { + fprintf(stderr, "Unable to open %s: %s\n", RANDOM, strerror(errno)); + exit(1); + } + randout = open("random.raw", O_WRONLY|O_TRUNC|O_CREAT, 0666); + if (randout < 0) { + fprintf(stderr, "Unable to open random.raw: %s\n", strerror(errno)); + exit(1); + } + hdlcout = open("random.hdlc", O_WRONLY|O_TRUNC|O_CREAT, 0666); + if (hdlcout < 0) { + fprintf(stderr, "Unable to open random.hdlc: %s\n", strerror(errno)); + exit(1); + } + for (;;) { + cnt = (rand() % 256) + 4; /* Read a pseudo-random amount of stuff */ + res = myread(randin, buf, cnt); + if (res != cnt) { + fprintf(stderr, "Tried to read %d bytes, but read %d instead\n", cnt, res); + exit(1); + } + res = write(randout, buf, cnt); + if (res != cnt) { + fprintf(stderr, "Tried to write %d bytes, but wrote %d instead\n", cnt, res); + exit(1); + } + /* HDLC encode */ + hdlccnt = 0; + /* Start with a flag */ + fasthdlc_tx_frame(&transmitter); + if (transmitter.bits >= 8) + outbuf[hdlccnt++] = fasthdlc_tx_run(&transmitter); + for (x=0;x<cnt;x++) { + res = fasthdlc_tx_load(&transmitter, buf[x]); + if (res < 0) { + fprintf(stderr, "Unable to load byte :(\n"); + exit(1); + } + while(transmitter.bits >= 8) { + outbuf[hdlccnt++] = fasthdlc_tx_run(&transmitter); + } + } + flags = (rand() % 4); + for (x=0;x<flags;x++) { + if (transmitter.bits < 8) + fasthdlc_tx_frame(&transmitter); + else + fprintf(stderr, "Huh? Don't need a frame?\n"); + outbuf[hdlccnt++] = fasthdlc_tx_run(&transmitter); + } + if (argc > 1) + printf("Encoded %d byte message with %d bytes of HDLC and %d extra flags\n", cnt, hdlccnt, flags); + res = write(hdlcout, outbuf, hdlccnt); + if (res != hdlccnt) { + fprintf(stderr, "Tried to write %d HDLC bytes, but wrote %d instead\n", cnt, res); + exit(1); + } + + } +} |