diff options
Diffstat (limited to 'util')
| -rw-r--r-- | util/nvmutil/nvmutil.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/util/nvmutil/nvmutil.c b/util/nvmutil/nvmutil.c index 8bb42bf5..68840789 100644 --- a/util/nvmutil/nvmutil.c +++ b/util/nvmutil/nvmutil.c @@ -26,6 +26,7 @@ #ifdef __OpenBSD__ #include <sys/param.h> #endif +#include <sys/time.h> #include <sys/types.h> #include <sys/stat.h> @@ -51,6 +52,7 @@ typedef unsigned int uint32_t; #include <stdio.h> #include <stdlib.h> #include <string.h> +#include <time.h> #include <unistd.h> typedef char static_assert_char_is_8_bits[(CHAR_BIT == 8) ? 1 : -1]; @@ -161,6 +163,7 @@ static void set_mac_nib(size_t mac_str_pos, size_t mac_byte_pos, size_t mac_nib_pos); static uint16_t hextonum(char ch_s); static uint16_t rhex(void); +static uint16_t fallback_rand(void); static void write_mac_part(size_t partnum); /* @@ -434,6 +437,8 @@ static size_t cmd_index = CMD_NULL; typedef char assert_argc3[(ARGC_3==3)?1:-1]; typedef char assert_argc4[(ARGC_4==4)?1:-1]; +static int use_prng = 0; + int main(int argc, char *argv[]) { @@ -720,6 +725,12 @@ open_dev_urandom(void) rname = oldrandom; urandom_fd = open(rname, O_RDONLY); + if (urandom_fd != -1) + return; + + /* fallback on VERY VERY VERY old unix */ + use_prng = 1; + srand((unsigned)(time(NULL) ^ getpid())); } static void @@ -996,6 +1007,14 @@ rhex(void) static size_t n = 0; static uint8_t rnum[12]; + if (use_prng) { + /* + * On very old Unix systems that + * lack /dev/random and /dev/urandom + */ + return fallback_rand(); + } + if (urandom_fd < 0) err(ECANCELED, "Your operating system has no /dev/[u]random"); @@ -1008,6 +1027,22 @@ rhex(void) return (uint16_t)(rnum[--n] & 0xf); } +static uint16_t +fallback_rand(void) +{ + struct timeval tv; + unsigned long mix; + + gettimeofday(&tv, NULL); + + mix = (unsigned long)tv.tv_sec + ^ (unsigned long)tv.tv_usec + ^ (unsigned long)getpid() + ^ (unsigned long)(uintptr_t)&mix; + + return (uint16_t)(mix & 0xf); +} + static void write_mac_part(size_t partnum) { |