cngf-pf

commit fb6ea6a60071ea36a485ef60394b247e00918e89
parent 505d04b123cfb85d445042d88900ed96df6d1d4e
Author: Anders Damsgaard <anders@adamsgaard.dk>
Date:   Thu, 22 Apr 2021 12:30:32 +0200

use secure snprintf idiom

Diffstat:
M
cngf-pf.c
 | 
10
++++++----
M
simulation.c
 | 
28
+++++++++++++++++++---------

2 files changed, 25 insertions(+), 13 deletions(-)
diff --git a/cngf-pf.c b/cngf-pf.c
@@ -69,7 +69,7 @@ usage(void)
 int
 main(int argc, char *argv[])
 {
-	int i, normalize, dt_override;
+	int i, normalize, dt_override, ret;
 	unsigned long iter;
 	double new_phi, new_k, filetimeclock;
 	struct simulation sim;
@@ -228,9 +228,11 @@ main(int argc, char *argv[])
 		usage();
 	} ARGEND;
 
-	if (argc == 1 && argv[0])
-		snprintf(sim.name, sizeof(sim.name), "%s", argv[0]);
-	else if (argc > 1)
+	if (argc == 1 && argv[0]) {
+		ret = snprintf(sim.name, sizeof(sim.name), "%s", argv[0]);
+		if (ret < 0 || (size_t)ret >= sizeof(sim.name))
+			errx(1, "%s: could not write sim.name", __func__);
+	} else if (argc > 1)
 		usage();
 
 	if (sim.nz < 1)
diff --git a/simulation.c b/simulation.c
@@ -20,7 +20,11 @@
 void
 init_sim(struct simulation *sim)
 {
-	snprintf(sim->name, sizeof(sim->name), DEFAULT_SIMULATION_NAME);
+	int ret;
+
+	ret = snprintf(sim->name, sizeof(sim->name), DEFAULT_SIMULATION_NAME);
+	if (ret < 0 || (size_t)ret == sizeof(sim->name))
+		err(1, "%s: could not write simulation name", __func__);
 
 	sim->G = 9.81;
 
@@ -212,18 +216,21 @@ warn_parameter_value(const char message[],
 static void
 check_float(const char name[], const double value, int *return_status)
 {
+	int ret;
+	char message[100];
+
 #ifdef SHOW_PARAMETERS
 	printf("%30s: %.17g\n", name, value);
 #endif
 	if (isnan(value)) {
-		char message[100];
-
-		snprintf(message, sizeof(message), "%s is NaN", name);
+		ret = snprintf(message, sizeof(message), "%s is NaN", name);
+		if (ret < 0 || (size_t)ret >= sizeof(message))
+			errx(1, "%s: message parsing", __func__);
 		warn_parameter_value(message, value, return_status);
 	} else if (isinf(value)) {
-		char message[100];
-
-		snprintf(message, sizeof(message), "%s is infinite", name);
+		ret = snprintf(message, sizeof(message), "%s is infinite", name);
+		if (ret < 0 || (size_t)ret >= sizeof(message))
+			errx(1, "%s: message parsing", __func__);
 		warn_parameter_value(message, value, return_status);
 	}
 }
@@ -711,11 +718,14 @@ implicit_1d_jacobian_poisson_solver(struct simulation *sim,
 void
 write_output_file(struct simulation *sim, const int normalize)
 {
+	int ret;
 	char outfile[200];
 	FILE *fp;
 
-	snprintf(outfile, sizeof(outfile), "%s.output%05d.txt",
-	         sim->name, sim->n_file++);
+	ret = snprintf(outfile, sizeof(outfile), "%s.output%05d.txt",
+	               sim->name, sim->n_file++);
+	if (ret < 0 || (size_t)ret >= sizeof(outfile))
+		errx(1, "%s: outfile snprintf", __func__);
 
 	if ((fp = fopen(outfile, "w")) != NULL) {
 		print_output(sim, fp, normalize);