check for fgets/fscanf return values
Aaron Marcher info@nulltime.net
Tue, 13 Jun 2017 00:06:56 +0200
1 files changed,
75 insertions(+),
35 deletions(-)
jump to
M
slstatus.c
→
slstatus.c
@@ -99,7 +99,7 @@
static const char * battery_perc(const char *bat) { - int perc; + int n, perc; char path[PATH_MAX]; FILE *fp;@@ -109,8 +109,10 @@ if (fp == NULL) {
warn("Failed to open file %s", path); return UNKNOWN_STR; } - fscanf(fp, "%i", &perc); + n = fscanf(fp, "%i", &perc); fclose(fp); + if (n != 1) + return UNKNOWN_STR; return bprintf("%d", perc); }@@ -120,7 +122,7 @@ battery_power(const char *bat)
{ char path[PATH_MAX]; FILE *fp; - int watts; + int n, watts; snprintf(path, sizeof(path), "%s%s%s", "/sys/class/power_supply/", bat, "/power_now"); fp = fopen(path, "r");@@ -128,8 +130,10 @@ if (fp == NULL) {
warn("Failed to open file %s", path); return UNKNOWN_STR; } - fscanf(fp, "%i", &watts); + n = fscanf(fp, "%i", &watts); fclose(fp); + if (n != 1) + return UNKNOWN_STR; return bprintf("%d", (watts + 500000) / 1000000); }@@ -140,6 +144,7 @@ {
char path[PATH_MAX]; char state[12]; FILE *fp; + int n; snprintf(path, sizeof(path), "%s%s%s", "/sys/class/power_supply/", bat, "/status"); fp = fopen(path, "r");@@ -147,8 +152,10 @@ if (fp == NULL) {
warn("Failed to open file %s", path); return UNKNOWN_STR; } - fscanf(fp, "%12s", state); + n = fscanf(fp, "%12s", state); fclose(fp); + if (n != 1) + return UNKNOWN_STR; if (strcmp(state, "Charging") == 0) { return "+";@@ -166,7 +173,7 @@
static const char * cpu_freq(void) { - int freq; + int n, freq; FILE *fp; fp = fopen("/sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq", "r");@@ -174,8 +181,10 @@ if (fp == NULL) {
warn("Failed to open file /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq"); return UNKNOWN_STR; } - fscanf(fp, "%i", &freq); + n = fscanf(fp, "%i", &freq); fclose(fp); + if (n != 1) + return UNKNOWN_STR; return bprintf("%d", (freq + 500) / 1000); }@@ -183,7 +192,7 @@
static const char * cpu_perc(void) { - int perc; + int n, perc; long double a[4], b[4]; FILE *fp;@@ -192,8 +201,10 @@ if (fp == NULL) {
warn("Failed to open file /proc/stat"); return UNKNOWN_STR; } - fscanf(fp, "%*s %Lf %Lf %Lf %Lf", &a[0], &a[1], &a[2], &a[3]); + n = fscanf(fp, "%*s %Lf %Lf %Lf %Lf", &a[0], &a[1], &a[2], &a[3]); fclose(fp); + if (n != 4) + return UNKNOWN_STR; delay++; sleep(delay);@@ -203,8 +214,10 @@ if (fp == NULL) {
warn("Failed to open file /proc/stat"); return UNKNOWN_STR; } - fscanf(fp, "%*s %Lf %Lf %Lf %Lf", &b[0], &b[1], &b[2], &b[3]); + n = fscanf(fp, "%*s %Lf %Lf %Lf %Lf", &b[0], &b[1], &b[2], &b[3]); fclose(fp); + if (n != 4) + return UNKNOWN_STR; perc = 100 * ((b[0]+b[1]+b[2]) - (a[0]+a[1]+a[2])) / ((b[0]+b[1]+b[2]+b[3]) - (a[0]+a[1]+a[2]+a[3])); return bprintf("%d", perc);@@ -280,7 +293,7 @@
static const char * entropy(void) { - int num; + int n, num; FILE *fp; fp= fopen("/proc/sys/kernel/random/entropy_avail", "r");@@ -288,8 +301,10 @@ if (fp == NULL) {
warn("Failed to open file /proc/sys/kernel/random/entropy_avail"); return UNKNOWN_STR; } - fscanf(fp, "%d", &num); + n = fscanf(fp, "%d", &num); fclose(fp); + if (n != 1) + return UNKNOWN_STR; return bprintf("%d", num); }@@ -392,14 +407,17 @@ ram_free(void)
{ long free; FILE *fp; + int n; fp = fopen("/proc/meminfo", "r"); if (fp == NULL) { warn("Failed to open file /proc/meminfo"); return UNKNOWN_STR; } - fscanf(fp, "MemFree: %ld kB\n", &free); + n = fscanf(fp, "MemFree: %ld kB\n", &free); fclose(fp); + if (n != 1) + return UNKNOWN_STR; return bprintf("%f", (float)free / 1024 / 1024); }@@ -415,13 +433,19 @@ if (fp == NULL) {
warn("Failed to open file /proc/meminfo"); return UNKNOWN_STR; } - fscanf(fp, "MemTotal: %ld kB\n", &total); - fscanf(fp, "MemFree: %ld kB\n", &free); - fscanf(fp, "MemAvailable: %ld kB\nBuffers: %ld kB\n", &buffers, &buffers); - fscanf(fp, "Cached: %ld kB\n", &cached); + if (fscanf(fp, "MemTotal: %ld kB\n", &total) != 1 || + fscanf(fp, "MemFree: %ld kB\n", &free) != 1 || + fscanf(fp, "MemAvailable: %ld kB\nBuffers: %ld kB\n", + &buffers, &buffers) != 2 || + fscanf(fp, "Cached: %ld kB\n", &cached) != 1) + goto scanerr; fclose(fp); return bprintf("%d", 100 * ((total - free) - (buffers + cached)) / total); + +scanerr: + fclose(fp); + return UNKNOWN_STR; } static const char *@@ -429,14 +453,17 @@ ram_total(void)
{ long total; FILE *fp; + int n; fp = fopen("/proc/meminfo", "r"); if (fp == NULL) { warn("Failed to open file /proc/meminfo"); return UNKNOWN_STR; } - fscanf(fp, "MemTotal: %ld kB\n", &total); + n = fscanf(fp, "MemTotal: %ld kB\n", &total); fclose(fp); + if (n != 1) + return UNKNOWN_STR; return bprintf("%f", (float)total / 1024 / 1024); }@@ -452,19 +479,25 @@ if (fp == NULL) {
warn("Failed to open file /proc/meminfo"); return UNKNOWN_STR; } - fscanf(fp, "MemTotal: %ld kB\n", &total); - fscanf(fp, "MemFree: %ld kB\n", &free); - fscanf(fp, "MemAvailable: %ld kB\nBuffers: %ld kB\n", &buffers, &buffers); - fscanf(fp, "Cached: %ld kB\n", &cached); + if (fscanf(fp, "MemTotal: %ld kB\n", &total) != 1 || + fscanf(fp, "MemFree: %ld kB\n", &free) != 1 || + fscanf(fp, "MemAvailable: %ld kB\nBuffers: %ld kB\n", + &buffers, &buffers) != 2 || + fscanf(fp, "Cached: %ld kB\n", &cached) != 1) + goto scanerr; fclose(fp); return bprintf("%f", (float)(total - free - buffers - cached) / 1024 / 1024); + +scanerr: + fclose(fp); + return UNKNOWN_STR; } static const char * run_command(const char *cmd) { - char *nlptr; + char *p; FILE *fp; fp = popen(cmd, "r");@@ -472,10 +505,12 @@ if (fp == NULL) {
warn("Failed to get command output for %s", cmd); return UNKNOWN_STR; } - fgets(buf, sizeof(buf) - 1, fp); + p = fgets(buf, sizeof(buf) - 1, fp); pclose(fp); - if ((nlptr = strrchr(buf, '\n')) != NULL) - nlptr[0] = '\0'; + if (!p) + return UNKNOWN_STR; + if ((p = strrchr(buf, '\n')) != NULL) + p[0] = '\0'; return buf[0] ? buf : UNKNOWN_STR; }@@ -613,7 +648,7 @@
static const char * temp(const char *file) { - int temp; + int n, temp; FILE *fp; fp = fopen(file, "r");@@ -621,8 +656,10 @@ if (fp == NULL) {
warn("Failed to open file %s", file); return UNKNOWN_STR; } - fscanf(fp, "%d", &temp); + n = fscanf(fp, "%d", &temp); fclose(fp); + if (n != 1) + return UNKNOWN_STR; return bprintf("%d", temp / 1000); }@@ -697,8 +734,8 @@
static const char * wifi_perc(const char *iface) { - int perc; - char *datastart; + int i, perc; + char *p, *datastart; char path[PATH_MAX]; char status[5]; FILE *fp;@@ -709,9 +746,9 @@ if (fp == NULL) {
warn("Failed to open file %s", path); return UNKNOWN_STR; } - fgets(status, 5, fp); + p = fgets(status, 5, fp); fclose(fp); - if(strcmp(status, "up\n") != 0) { + if(!p || strcmp(status, "up\n") != 0) { return UNKNOWN_STR; }@@ -721,10 +758,13 @@ warn("Failed to open file /proc/net/wireless");
return UNKNOWN_STR; } - fgets(buf, sizeof(buf) - 1, fp); - fgets(buf, sizeof(buf) - 1, fp); - fgets(buf, sizeof(buf) - 1, fp); + for (i = 0; i < 3; i++) { + if (!(p = fgets(buf, sizeof(buf) - 1, fp))) + break; + } fclose(fp); + if (i < 2 || !p) + return UNKNOWN_STR; if ((datastart = strstr(buf, iface)) == NULL) return UNKNOWN_STR;