check_swap stuff: improve error handling

1 files changed, 40 insertions, 19 deletions

diff --git a/plugins/check_swap.d/swap.c b/plugins/check_swap.d/swap.c
index ece05fd2..9133c4fe 100644
--- a/plugins/check_swap.d/swap.c
+++ b/plugins/check_swap.d/swap.c
@@ -73,6 +73,10 @@ swap_result getSwapFromProcMeminfo(char proc_meminfo[]) {
         uint64_t swap_used = 0;
         uint64_t swap_free = 0;
 
+        bool found_total = false;
+        bool found_used = false;
+        bool found_free = false;
+
         char input_buffer[MAX_INPUT_BUFFER];
         char str[32];
 
@@ -92,7 +96,11 @@ swap_result getSwapFromProcMeminfo(char proc_meminfo[]) {
                         result.metrics.used += swap_used;
                         result.metrics.free += swap_free;
 
-                        // Set error 
+                        found_total = true;
+                        found_free = true;
+                        found_used = true;
+
+                        // Set error
                         result.errorcode = STATE_OK;
 
                         /*
@@ -100,25 +108,34 @@ swap_result getSwapFromProcMeminfo(char proc_meminfo[]) {
                          * "SwapTotal: 123" and "SwapFree: 123" This format exists at least
                          * on Debian Linux with a 5.* kernel
                          */
-                } else if (sscanf(input_buffer,
-                                                  "%*[S]%*[w]%*[a]%*[p]%[TotalFreCchd]%*[:] %lu "
-                                                  "%*[k]%*[B]",
-                                                  str, &tmp_KB) == 2) {
-
-                        if (verbose >= 3) {
-                                printf("Got %s with %lu\n", str, tmp_KB);
-                        }
-
-                        /* I think this part is always in Kb, so convert to bytes */
-                        if (strcmp("Total", str) == 0) {
-                                swap_total = tmp_KB * 1024;
-                        } else if (strcmp("Free", str) == 0) {
-                                swap_free = swap_free + tmp_KB * 1024;
-                        } else if (strcmp("Cached", str) == 0) {
-                                swap_free = swap_free + tmp_KB * 1024;
+                } else {
+                        int sscanf_result = sscanf(input_buffer,
+                                                                           "%*[S]%*[w]%*[a]%*[p]%[TotalFreCchd]%*[:] %lu "
+                                                                           "%*[k]%*[B]",
+                                                                           str, &tmp_KB);
+
+                        if (sscanf_result == 2) {
+
+                                if (verbose >= 3) {
+                                        printf("Got %s with %lu\n", str, tmp_KB);
+                                }
+
+                                /* I think this part is always in Kb, so convert to bytes */
+                                if (strcmp("Total", str) == 0) {
+                                        swap_total = tmp_KB * 1000;
+                                        found_total = true;
+                                } else if (strcmp("Free", str) == 0) {
+                                        swap_free = swap_free + tmp_KB * 1000;
+                                        found_free = true;
+                                        found_used = true; // No explicit used metric available
+                                } else if (strcmp("Cached", str) == 0) {
+                                        swap_free = swap_free + tmp_KB * 1000;
+                                        found_free = true;
+                                        found_used = true; // No explicit used metric available
+                                }
+
+                                result.errorcode = STATE_OK;
                         }
-
-                        result.errorcode = STATE_OK;
                 }
         }
 
@@ -128,6 +145,10 @@ swap_result getSwapFromProcMeminfo(char proc_meminfo[]) {
         result.metrics.used = swap_total - swap_free;
         result.metrics.free = swap_free;
 
+        if (!found_free || !found_total || !found_used) {
+                result.errorcode = STATE_UNKNOWN;
+        }
+
         return result;
 }