From c32c317f7ecfe5af5da64be4c8cac8d87db04654 Mon Sep 17 00:00:00 2001
From: Thomas Habets <thomas@habets.se>
Date: Wed, 26 Oct 2022 21:09:16 +0100
Subject: Parse -wW strictly as float

---
 src/arping.c      | 49 +++++++++++++++++++++++++++++++++++++---
 src/arping_test.c | 67 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 113 insertions(+), 3 deletions(-)

diff --git a/src/arping.c b/src/arping.c
index a2717cd..d09b9ec 100644
--- a/src/arping.c
+++ b/src/arping.c
@@ -238,6 +238,32 @@ int verbose = 0;  /* Increase with -v */
 /* Doesn't really need to be volatile, but doesn't hurt. */
 static volatile sig_atomic_t time_to_die = 0;
 
+static float
+must_parse_float(const char* in, const char* what)
+{
+        if (!*in) {
+                fprintf(stderr, "arping: %s: value was empty\n", what);
+                exit(1);
+        }
+        char *endp = NULL;
+        errno = 0;
+        // Maybe need to use strtod() instead? It's in C89, whereas
+        // looks like strtof() is in POSIX.1-2001, POSIX.1-2008, C99.
+        const float ret = strtof(in, &endp);
+        if (errno) {
+                fprintf(stderr, "arping: %s: parsing <%s> as float: %s\n",
+                        what, in, strerror(errno));
+                exit(1);
+        }
+        if (*endp) {
+                fprintf(stderr,
+                        "arping: %s: failed parsing <%s> as float\n",
+                        what, in);
+                exit(1);
+        }
+        return ret;
+}
+
 static int
 must_parse_int(const char* in, const char* what)
 {
@@ -2111,11 +2137,28 @@ arping_main(int argc, char **argv)
                         }
                         break;
 		case 'w':
-                        deadline = atof(optarg);
+                        deadline = must_parse_float(optarg, "deadline (-w)");
+                        if (deadline < 0) {
+                                fprintf(stderr,
+                                        "arping: deadline (-w) must be >=0. Is %f\n",
+                                        deadline);
+                                exit(1);
+                        }
 			break;
-                case 'W':
-                        packetwait = (unsigned)(1000000.0 * atof(optarg));
+                case 'W': {
+                        const float val = must_parse_float(optarg,
+                                                           "packetwait (-W)");
+                        // TODO: range check into unsigned.
+                        // Also turns out zero doesn't work.
+                        packetwait = (unsigned)(1000000.0 * val);
+                        if (val < 0) {
+                                fprintf(stderr,
+                                        "arping: packetwait (-W) must be >=0. Is %f\n",
+                                        val);
+                                exit(1);
+                        }
                         break;
+                }
                 case 'z':
                         use_seccomp = 1;
                         break;
diff --git a/src/arping_test.c b/src/arping_test.c
index 9166c54..9db2d60 100644
--- a/src/arping_test.c
+++ b/src/arping_test.c
@@ -497,6 +497,7 @@ START_TEST(badarg_maxcount_neg)
         char* args[] = {
                 "arping",
                 "-c", "-1",
+                "-h", // To exit cleanly.
                 "dummy",
                 NULL
         };
@@ -508,6 +509,19 @@ START_TEST(badarg_maxcount_nan)
         char* args[] = {
                 "arping",
                 "-c", "number",
+                "-h", // To exit cleanly.
+                "dummy",
+                NULL
+        };
+        arping_main(sizeof(args)/sizeof(char*)-1, args);
+}
+
+START_TEST(badarg_maxcount_range)
+{
+        char* args[] = {
+                "arping",
+                "-c", "100000000000000000000000000000",
+                "-h", // To exit cleanly.
                 "dummy",
                 NULL
         };
@@ -538,6 +552,54 @@ START_TEST(arg_maxcount_hex)
         arping_main(sizeof(args)/sizeof(char*)-1, args);
 }
 
+START_TEST(badarg_packetwait_neg)
+{
+        char* args[] = {
+                "arping",
+                "-W", "-1",
+                "-h", // To exit cleanly.
+                "dummy",
+                NULL
+        };
+        arping_main(sizeof(args)/sizeof(char*)-1, args);
+}
+
+START_TEST(badarg_packetwait_nan)
+{
+        char* args[] = {
+                "arping",
+                "-W", "huteosu",
+                "-h", // To exit cleanly.
+                "dummy",
+                NULL
+        };
+        arping_main(sizeof(args)/sizeof(char*)-1, args);
+}
+
+START_TEST(badarg_packetwait_range)
+{
+        char* args[] = {
+                "arping",
+                "-W", "10000000000000000000000000000000000000000",
+                "-h", // To exit cleanly.
+                "dummy",
+                NULL
+        };
+        arping_main(sizeof(args)/sizeof(char*)-1, args);
+}
+
+START_TEST(arg_packetwait_good)
+{
+        char* args[] = {
+                "arping",
+                "-W", "1.2",
+                "-h", // To exit cleanly.
+                "dummy",
+                NULL
+        };
+        arping_main(sizeof(args)/sizeof(char*)-1, args);
+}
+
 START_TEST(libnet_init_bad_nolo)
 {
         // It'll only try lo if named interface fails.
@@ -595,6 +657,7 @@ arping_suite(void)
         SIGH_LIBCHECK(libnet_init_good);
         SIGH_LIBCHECK(arg_maxcount_good);
         SIGH_LIBCHECK(arg_maxcount_hex);
+        SIGH_LIBCHECK(arg_packetwait_good);
 
 #define SIGH_LIBCHECK_EXIT(tn)          \
         tc_core = tcase_create(#tn);   \
@@ -603,6 +666,10 @@ arping_suite(void)
 
         SIGH_LIBCHECK_EXIT(badarg_maxcount_neg);
         SIGH_LIBCHECK_EXIT(badarg_maxcount_nan);
+        SIGH_LIBCHECK_EXIT(badarg_maxcount_range);
+        SIGH_LIBCHECK_EXIT(badarg_packetwait_neg);
+        SIGH_LIBCHECK_EXIT(badarg_packetwait_nan);
+        SIGH_LIBCHECK_EXIT(badarg_packetwait_range);
         SIGH_LIBCHECK_EXIT(libnet_init_bad_nolo);
         SIGH_LIBCHECK_EXIT(libnet_init_null_nolo_nonull);
 
-- 
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