1 files changed, 124 insertions, 0 deletions

diff --git a/regress/modpipe.c b/regress/modpipe.c
new file mode 100755
index 000000000..439be4c9d
--- /dev/null
+++ b/regress/modpipe.c
@@ -0,0 +1,124 @@
+/*
+ * Copyright (c) 2012 Damien Miller <djm@mindrot.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* $Id: modpipe.c,v 1.1 2012/12/11 23:54:40 djm Exp $ */
+
+#include <sys/types.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <err.h>
+#include <errno.h>
+
+static void
+usage(void)
+{
+        fprintf(stderr, "Usage: modpipe [-m modspec ...] < in > out\n");
+        fprintf(stderr, "modspec is one of:\n");
+        fprintf(stderr, "    xor:offset:value       - XOR \"value\" at \"offset\"\n");
+        fprintf(stderr, "    andor:offset:val1:val2 - AND \"val1\" then OR \"val2\" at \"offset\"\n");
+        exit(1);
+}
+
+#define MAX_MODIFICATIONS 256
+struct modification {
+        enum { MOD_XOR, MOD_AND_OR } what;
+        u_int64_t offset;
+        u_int8_t m1, m2;
+};
+
+static void
+parse_modification(const char *s, struct modification *m)
+{
+        char what[16+1];
+        int n;
+
+        bzero(m, sizeof(*m));
+        if ((n = sscanf(s, "%16[^:]%*[:]%lli%*[:]%hhi%*[:]%hhi",
+            what, &m->offset, &m->m1, &m->m2)) < 3)
+                errx(1, "Invalid modification spec \"%s\"", s);
+        if (strcasecmp(what, "xor") == 0) {
+                m->what = MOD_XOR;
+                if (n > 3)
+                        errx(1, "Invalid modification spec \"%s\"", s);
+        } else if (strcasecmp(what, "andor") == 0) {
+                m->what = MOD_AND_OR;
+                if (n != 4)
+                        errx(1, "Invalid modification spec \"%s\"", s);
+        } else
+                errx(1, "Invalid modification type \"%s\"", what);
+}
+
+int
+main(int argc, char **argv)
+{
+        int ch;
+        u_char buf[8192];
+        size_t total;
+        ssize_t r, s, o;
+        struct modification mods[MAX_MODIFICATIONS];
+        u_int i, num_mods = 0;
+
+        while ((ch = getopt(argc, argv, "m:")) != -1) {
+                switch (ch) {
+                case 'm':
+                        if (num_mods >= MAX_MODIFICATIONS)
+                                errx(1, "Too many modifications");
+                        parse_modification(optarg, &(mods[num_mods++]));
+                        break;
+                default:
+                        usage();
+                        /* NOTREACHED */
+                }
+        }
+        for (total = 0;;) {
+                r = s = read(STDIN_FILENO, buf, sizeof(buf));
+                if (r == 0)
+                        return 0;
+                if (r < 0) {
+                        if (errno == EAGAIN || errno == EINTR)
+                                continue;
+                        err(1, "read");
+                }
+                for (i = 0; i < num_mods; i++) {
+                        if (mods[i].offset < total ||
+                            mods[i].offset >= total + s)
+                                continue;
+                        switch (mods[i].what) {
+                        case MOD_XOR:
+                                buf[mods[i].offset - total] ^= mods[i].m1;
+                                break;
+                        case MOD_AND_OR:
+                                buf[mods[i].offset - total] &= mods[i].m1;
+                                buf[mods[i].offset - total] |= mods[i].m2;
+                                break;
+                        }
+                }
+                for (o = 0; o < s; o += r) {
+                        r = write(STDOUT_FILENO, buf, s - o);
+                        if (r == 0)
+                                return 0;
+                        if (r < 0) {
+                                if (errno == EAGAIN || errno == EINTR)
+                                        continue;
+                                err(1, "write");
+                        }
+                }
+                total += s;
+        }
+        return 0;
+}