179e88bec
Denys Vlasenko
2017-01-20
Subject
rdate: make it do something remotely sane, facing 32-bit time overflow
Binary
No binary (build failed)
Architecture & Compiler Flags
—
Build Log
(log yok)
Commit Diff GitHub →
networking/inetd.c+1 -1
| @@ -1677,7 +1677,7 @@ static uint32_t machtime(void) | |
| struct timeval tv; | |
| gettimeofday(&tv, NULL); | |
| - | return htonl((uint32_t)(tv.tv_sec + 2208988800)); |
| + | return htonl((uint32_t)(tv.tv_sec + 2208988800U)); |
| } | |
| /* ARGSUSED */ | |
| static void FAST_FUNC machtime_stream(int s, servtab_t *sep UNUSED_PARAM) | |
util-linux/rdate.c+27 -6
| @@ -21,11 +21,11 @@ | |
| //kbuild:lib-$(CONFIG_RDATE) += rdate.o | |
| //usage:#define rdate_trivial_usage | |
| - | //usage: "[-sp] HOST" |
| + | //usage: "[-s/-p] HOST" |
| //usage:#define rdate_full_usage "\n\n" | |
| - | //usage: "Get and possibly set system time from a remote HOST\n" |
| - | //usage: "\n -s Set system time (default)" |
| - | //usage: "\n -p Print time" |
| + | //usage: "Set and print time from HOST using RFC 868\n" |
| + | //usage: "\n -s Only set system time" |
| + | //usage: "\n -p Only print time" |
| #include "libbb.h" | |
| @@ -58,8 +58,22 @@ static time_t askremotedate(const char *host) | |
| * the RFC 868 time 2,208,988,800 corresponds to 00:00 1 Jan 1970 GMT | |
| * Subtract the RFC 868 time to get Linux epoch. | |
| */ | |
| - | |
| - | return ntohl(nett) - RFC_868_BIAS; |
| + | nett = ntohl(nett) - RFC_868_BIAS; |
| + | |
| + | if (sizeof(time_t) > 4) { |
| + | /* Now we have 32-bit lsb of a wider time_t |
| + | * Imagine that nett = 0x00000001, |
| + | * current time cur = 0x123ffffffff. |
| + | * Assuming our time is not some 40 years off, |
| + | * remote time must be 0x12400000001. |
| + | * Need to adjust out time by (int32_t)(nett - cur). |
| + | */ |
| + | time_t cur = time(NULL); |
| + | int32_t adjust = (int32_t)(nett - (uint32_t)cur); |
| + | return cur + adjust; |
| + | } |
| + | /* This is not going to work, but what can we do */ |
| + | return (time_t)nett; |
| } | |
| int rdate_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; | |
| @@ -73,6 +87,13 @@ int rdate_main(int argc UNUSED_PARAM, char **argv) | |
| remote_time = askremotedate(argv[optind]); | |
| + | /* Manpages of various Unixes are confusing. What happens is: |
| + | * (no opts) set and print time |
| + | * -s: set time ("do not print the time") |
| + | * -p: print time ("do not set, just print the remote time") |
| + | * -sp: print time (that's what we do, not sure this is right) |
| + | */ |
| + | |
| if (!(flags & 2)) { /* no -p (-s may be present) */ | |
| time_t current_time; | |