From 4c39cb09735a494099fba0474d25ff26800de952 Mon Sep 17 00:00:00 2001 From: Lee Duncan Date: Wed, 29 Jan 2020 12:47:16 -0800 Subject: [PATCH 3/7] Do not ignore write() return value. Some distros set the warn_unused_result attribute for the write() system call, so check the return value. --- pki.c | 37 ++++++++++++++++++++++++++++++++----- 1 file changed, 32 insertions(+), 5 deletions(-) diff --git a/pki.c b/pki.c index 486d9bb..57ea664 100644 --- a/pki.c +++ b/pki.c @@ -9,12 +9,13 @@ #include #include #include "config.h" +#include +#include #ifdef WITH_SECURITY #include #include #include #endif -#include #include #include "security.h" #include @@ -431,17 +432,43 @@ isns_dsa_load_params(const char *filename) return dsa; } +/* + * write one 'status' character to stdout + */ +static void +write_status_byte(int ch) +{ + static int stdout_fd = 1; /* fileno(stdout) */ + char buf[2]; + int res; + + /* + * We don't actually care about the return value here, since + * we are just dumping a status byte to stdout, but + * some linux distrubutions set the warn_unused_result attribute + * for the write() API, so we might as well use the return value + * to make sure the write command isn't broken. + */ + assert(ch); + buf[0] = ch; + buf[1] = '\0'; + res = write(stdout_fd, buf, 1); + assert(res == 1); +} + static int isns_dsa_param_gen_callback(int stage, __attribute__((unused))int index, __attribute__((unused))void *dummy) { if (stage == 0) - write(1, "+", 1); + write_status_byte('+'); else if (stage == 1) - write(1, ".", 1); + write_status_byte('.'); else if (stage == 2) - write(1, "/", 1); + write_status_byte('/'); + + /* as a callback, we must return a value, so just return success */ return 0; } @@ -478,7 +505,7 @@ isns_dsa_init_params(const char *filename) dsa = DSA_generate_parameters(dsa_key_bits, NULL, 0, NULL, NULL, isns_dsa_param_gen_callback, NULL); #endif - write(1, "\n", 1); + write_status_byte('\n'); if (dsa == NULL) { isns_dsasig_report_errors("Error generating DSA parameters", -- 2.18.1