Atomize output files

I feel like I need to relearn signals every time I have to interact with
them. Best get this done while the iron's hot.

1. The ROA file is first written as `<cache>/.roa`.
   The RK file is first written as `<cache>/.rk`.
2. When the validation run is done, `.roa` is renamed to `--output.roa`,
   and `.rk` becomes `--output.bgpsec`.
3. Most terminating signals unlink `.roa` and `.rk`.

Fixes #124.

diff --git a/src/main.c b/src/main.c
index 014a1afcd9ae35ed3c15a6a6acb5efb229be7e13..ee61d7d69412b6b49815d2ddd28bed95558bd187 100644 (file)
--- a/src/main.c
+++ b/src/main.c
@@ -7,6 +7,7 @@
 #include "http.h"
 #include "log.h"
 #include "nid.h"
+#include "output_printer.h"
 #include "print_file.h"
 #include "relax_ng.h"
 #include "rtr/rtr.h"
@@ -153,6 +154,9 @@ main(int argc, char **argv)
        error = cache_setup();
        if (error)
                goto revert_vrps;
+       error = output_setup();
+       if (error)
+               goto revert_cache;
 
        /* Meat */
 
@@ -169,7 +173,7 @@ main(int argc, char **argv)
        }
 
        /* End */
-
+revert_cache:
        cache_teardown();
 revert_vrps:
        vrps_destroy();

diff --git a/src/output_printer.c b/src/output_printer.c
index c9ecaf9fa94949425223cf5f0087b7f68a264f69..3b5e10f2a7c5ab2774af3f2ea96446991f358a74 100644 (file)
--- a/src/output_printer.c
+++ b/src/output_printer.c
@@ -10,8 +10,27 @@ typedef struct json_out {
        bool first;
 } JSON_OUT;
 
+int
+output_setup(void)
+{
+       int err1;
+       int err2;
+
+       errno = 0;
+       err1 = atexit(output_atexit);
+       if (err1) {
+               err2 = errno;
+               pr_op_err("Cannot register output's exit function.");
+               pr_op_err("Error message attempt 1: %s", strerror(err1));
+               pr_op_err("Error message attempt 2: %s", strerror(err2));
+               return err1;
+       }
+
+       return 0;
+}
+
 static FILE *
-load_output_file(char const *filename)
+load_output_file(char const *filename, char const *tmpname)
 {
        FILE *out;
 
@@ -21,7 +40,7 @@ load_output_file(char const *filename)
        if (strcmp(filename, "-") == 0)
                return stdout;
 
-       return (file_write(filename, "w", &out) == 0) ? out : NULL;
+       return (file_write(tmpname, "w", &out) == 0) ? out : NULL;
 }
 
 static int
@@ -130,7 +149,7 @@ print_roas(struct db_table const *db)
        JSON_OUT json_out;
        int error;
 
-       out = load_output_file(config_get_output_roa());
+       out = load_output_file(config_get_output_roa(), ".roa");
        if (out == NULL)
                return;
 
@@ -149,8 +168,12 @@ print_roas(struct db_table const *db)
 
        if (error)
                pr_op_err("Error printing ROAs: %s", strerror(error));
-       if (out != stdout)
+       if (out != stdout) {
                file_close(out);
+               if (!error && rename(".roa", config_get_output_roa()) < 0)
+                       pr_op_err("Cannot move '.roa' to '%s': %s",
+                           config_get_output_roa(), strerror(errno));
+       }
 }
 
 static void
@@ -160,7 +183,7 @@ print_router_keys(struct db_table const *db)
        JSON_OUT json_out;
        int error;
 
-       out = load_output_file(config_get_output_bgpsec());
+       out = load_output_file(config_get_output_bgpsec(), ".rk");
        if (out == NULL)
                return;
 
@@ -179,8 +202,12 @@ print_router_keys(struct db_table const *db)
 
        if (error)
                pr_op_err("Error printing Router Keys: %s", strerror(error));
-       if (out != stdout)
+       if (out != stdout) {
                file_close(out);
+               if (!error && rename(".rk", config_get_output_bgpsec()) < 0)
+                       pr_op_err("Cannot move '.rk' to '%s': %s",
+                           config_get_output_bgpsec(), strerror(errno));
+       }
 }
 
 void
@@ -189,3 +216,11 @@ output_print_data(struct db_table const *db)
        print_roas(db);
        print_router_keys(db);
 }
+
+/* THIS FUNCTION CAN BE CALLED FROM A SIGNAL HANDLER. */
+void
+output_atexit(void)
+{
+       unlink(".roa");
+       unlink(".rk");
+}

diff --git a/src/output_printer.h b/src/output_printer.h
index 92b5b6a15b156c5ed41123f6b8bda1098ca0e65d..35daaedf94945e748778f905df34b1f570c1688f 100644 (file)
--- a/src/output_printer.h
+++ b/src/output_printer.h
@@ -3,6 +3,8 @@
 
 #include "rtr/db/db_table.h"
 
+int output_setup(void);
 void output_print_data(struct db_table const *);
+void output_atexit(void);
 
 #endif /* SRC_OUTPUT_PRINTER_H_ */

diff --git a/src/sig.c b/src/sig.c
index daa7e376353c3723706344f26f8d61b82b19873e..9df78b18121d5147a652d564870ec962b29383e3 100644 (file)
--- a/src/sig.c
+++ b/src/sig.c
@@ -12,6 +12,7 @@
 
 #include "cache.h"
 #include "log.h"
+#include "output_printer.h"
 
 /*
  * Ensures libgcc is loaded; otherwise backtrace() might allocate
@@ -55,6 +56,7 @@ do_cleanup(int signum)
                print_stack_trace();
 
        cache_atexit();
+       output_atexit();
 
        /* Trigger default handler */
        signal(signum, SIG_DFL);