diff options
| -rw-r--r-- | libc/misc/time/time.c | 135 |
1 files changed, 132 insertions, 3 deletions
diff --git a/libc/misc/time/time.c b/libc/misc/time/time.c index 3f0ddf78d..378854adc 100644 --- a/libc/misc/time/time.c +++ b/libc/misc/time/time.c @@ -71,6 +71,28 @@ * TODO - Rework _time_mktime to remove the dependency on long long. */ +/* Oct 28, 2002 + * + * Fixed allowed char check for std and dst TZ fields. + * + * Added several options concerned with timezone support. The names will + * probably change once Erik gets the new config system in place. + * + * Defining __TIME_TZ_FILE causes tzset() to attempt to read the TZ value + * from the file /etc/TZ if the TZ env variable isn't set. The file contents + * must be the intended value of TZ, followed by a newline. No other chars, + * spacing, etc is allowed. As an example, an easy way for me to init + * /etc/TZ appropriately would be: echo CST6CDT > /etc/TZ + * + * Defining __TIME_TZ_FILE_ONCE will cause all further accesses of /etc/TZ + * to be skipped once a legal value has been read. + * + * Defining __TIME_TZ_OPT_SPEED will cause a tzset() to keep a copy of the + * last TZ setting string and do a "fast out" if the current string is the + * same. + */ + + #define _GNU_SOURCE #define _STDIO_UTILITY #include <stdio.h> @@ -93,9 +115,30 @@ #define TZNAME_MAX _POSIX_TZNAME_MAX #endif +/**********************************************************************/ + /* The era code is currently unfinished. */ /* #define ENABLE_ERA_CODE */ +#define __TIME_TZ_FILE +/* #define __TIME_TZ_FILE_ONCE */ + +#define __TIME_TZ_OPT_SPEED + +#define TZ_BUFLEN (2*TZNAME_MAX + 56) + +#ifdef __TIME_TZ_FILE +#include <sys/stat.h> +#include <fcntl.h> +#include <unistd.h> +/* ":<tzname>+hh:mm:ss<tzname>+hh:mm:ss,Mmm.w.d/hh:mm:ss,Mmm.w.d/hh:mm:ss" + nul */ +/* 1 + 2*(1+TZNAME_MAX+1 + 9 + 7 + 9) + 1 = 2*TZNAME_MAX + 56 */ +#else /* __TIME_TZ_FILE */ +#undef __TIME_TZ_FILE_ONCE +#endif /* __TIME_TZ_FILE */ + +/**********************************************************************/ + extern struct tm __time_tm; typedef struct { @@ -1476,6 +1519,50 @@ static const char *getnumber(register const char *e, int *pn) #endif /* __BCC__ */ } +#ifdef __TIME_TZ_FILE + +#ifdef __TIME_TZ_FILE_ONCE +static int TZ_file_read; /* Let BSS initialization set this to 0. */ +#endif /* __TIME_TZ_FILE_ONCE */ + +static char *read_TZ_file(char *buf) +{ + int fd; + ssize_t r; + size_t todo; + char *p = NULL; + + if ((fd = open("/etc/TZ", O_RDONLY)) >= 0) { + todo = TZ_BUFLEN; + p = buf; + do { + if ((r = read(fd, p, todo)) < 0) { + goto ERROR; + } + if (r == 0) { + break; + } + p += r; + todo -= r; + } while (todo); + + if ((p > buf) && (p[-1] == '\n')) { /* Must end with newline. */ + p[-1] = 0; + p = buf; +#ifdef __TIME_TZ_FILE_ONCE + ++TZ_file_read; +#endif /* __TIME_TZ_FILE_ONCE */ + } else { + ERROR: + p = NULL; + } + close(fd); + } + return p; +} + +#endif /* __TIME_TZ_FILE */ + void tzset(void) { register const char *e; @@ -1485,11 +1572,42 @@ void tzset(void) rule_struct new_rules[2]; int n, count, f; char c; +#ifdef __TIME_TZ_FILE + char buf[TZ_BUFLEN]; +#endif /* __TIME_TZ_FILE */ +#ifdef __TIME_TZ_OPT_SPEED + static char oldval[TZ_BUFLEN]; /* BSS-zero'd. */ +#endif /* __TIME_TZ_OPT_SPEED */ TZLOCK; - if (!(e = getenv(TZ)) || !*e) { /* Not set or set to empty string. */ + e = getenv(TZ); /* TZ env var always takes precedence. */ + +#ifdef __TIME_TZ_FILE_ONCE + /* Put this inside the lock to prevent the possiblity of two different + * timezones being used in a threaded app. */ + + if (e != NULL) { + TZ_file_read = 0; /* Reset if the TZ env var is set. */ + } else if (TZ_file_read > 0) { + goto FAST_DONE; + } +#endif /* __TIME_TZ_FILE_ONCE */ + + /* Warning!!! Since uClibc doesn't do lib locking, the following is + * potentially unsafe in a multi-threaded program since it is remotely + * possible that another thread could call setenv() for TZ and overwrite + * the string being parsed. So, don't do that... */ + + if ((!e /* TZ env var not set... */ +#ifdef __TIME_TZ_FILE + && !(e = read_TZ_file(buf)) /* and no file or invalid file */ +#endif /* __TIME_TZ_FILE */ + ) || !*e) { /* or set to empty string. */ ILLEGAL: /* TODO: Clean up the following... */ +#ifdef __TIME_TZ_OPT_SPEED + *oldval = 0; /* Set oldval tonnn empty string. */ +#endif /* __TIME_TZ_OPT_SPEED */ s = _time_tzinfo[0].tzname; *s = 'U'; *++s = 'T'; @@ -1500,10 +1618,19 @@ void tzset(void) goto DONE; } - if (*e == ':') { /* Ignore leading ':'. */ ++e; } + +#ifdef __TIME_TZ_OPT_SPEED + if (strcmp(e, oldval) == 0) { /* Same string as last time... */ + goto FAST_DONE; /* So nothing to do. */ + } + /* Make a copy of the TZ env string. It won't be nul-terminated if + * it is too long, but it that case it will be illegal and will be reset + * to the empty string anyway. */ + strncpy(oldval, e, TZ_BUFLEN); +#endif /* __TIME_TZ_OPT_SPEED */ count = 0; new_rules[1].tzname[0] = 0; @@ -1518,8 +1645,9 @@ void tzset(void) s = new_rules[count].tzname; n = 0; while (*e + && isascii(*e) /* SUSv3 requires char in portable char set. */ && (isalpha(*e) - || (c && (isdigit(*e) || (*e == '+') || (*e == '-')))) + || (c && (isalnum(*e) || (*e == '+') || (*e == '-')))) ) { *s++ = *e++; if (++n > TZNAME_MAX) { @@ -1621,6 +1749,7 @@ void tzset(void) daylight = !!new_rules[1].tzname[0]; timezone = new_rules[0].gmt_offset; + FAST_DONE: TZUNLOCK; } |