| /* |
| * Copyright (C) 2014 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include <ctype.h> |
| #include <errno.h> |
| #include <inttypes.h> |
| #include <limits.h> |
| #include <stdarg.h> |
| #include <stdlib.h> |
| #include <sys/prctl.h> |
| #include <sys/uio.h> |
| #include <syslog.h> |
| |
| #include <log/logger.h> |
| |
| #include "LogKlog.h" |
| |
| #define KMSG_PRIORITY(PRI) \ |
| '<', \ |
| '0' + (LOG_SYSLOG | (PRI)) / 10, \ |
| '0' + (LOG_SYSLOG | (PRI)) % 10, \ |
| '>' |
| |
| static const char priority_message[] = { KMSG_PRIORITY(LOG_INFO), '\0' }; |
| |
| // Parsing is hard |
| |
| // called if we see a '<', s is the next character, returns pointer after '>' |
| static char *is_prio(char *s, size_t len) { |
| if (!len || !isdigit(*s++)) { |
| return NULL; |
| } |
| --len; |
| static const size_t max_prio_len = (len < 4) ? len : 4; |
| size_t priolen = 0; |
| char c; |
| while (((c = *s++)) && (++priolen <= max_prio_len)) { |
| if (!isdigit(c)) { |
| return ((c == '>') && (*s == '[')) ? s : NULL; |
| } |
| } |
| return NULL; |
| } |
| |
| // called if we see a '[', s is the next character, returns pointer after ']' |
| static char *is_timestamp(char *s, size_t len) { |
| while (len && (*s == ' ')) { |
| ++s; |
| --len; |
| } |
| if (!len || !isdigit(*s++)) { |
| return NULL; |
| } |
| --len; |
| bool first_period = true; |
| char c; |
| while (len && ((c = *s++))) { |
| --len; |
| if ((c == '.') && first_period) { |
| first_period = false; |
| } else if (!isdigit(c)) { |
| return ((c == ']') && !first_period && (*s == ' ')) ? s : NULL; |
| } |
| } |
| return NULL; |
| } |
| |
| // Like strtok_r with "\r\n" except that we look for log signatures (regex) |
| // \(\(<[0-9]\{1,4\}>\)\([[] *[0-9]+[.][0-9]+[]] \)\{0,1\}\|[[] *[0-9]+[.][0-9]+[]] \) |
| // and split if we see a second one without a newline. |
| // We allow nuls in content, monitoring the overall length and sub-length of |
| // the discovered tokens. |
| |
| #define SIGNATURE_MASK 0xF0 |
| // <digit> following ('0' to '9' masked with ~SIGNATURE_MASK) added to signature |
| #define LESS_THAN_SIG SIGNATURE_MASK |
| #define OPEN_BRACKET_SIG ((SIGNATURE_MASK << 1) & SIGNATURE_MASK) |
| // space is one more than <digit> of 9 |
| #define OPEN_BRACKET_SPACE ((char)(OPEN_BRACKET_SIG | 10)) |
| |
| char *log_strntok_r(char *s, size_t *len, char **last, size_t *sublen) { |
| *sublen = 0; |
| if (!*len) { |
| return NULL; |
| } |
| if (!s) { |
| if (!(s = *last)) { |
| return NULL; |
| } |
| // fixup for log signature split <, |
| // LESS_THAN_SIG + <digit> |
| if ((*s & SIGNATURE_MASK) == LESS_THAN_SIG) { |
| *s = (*s & ~SIGNATURE_MASK) + '0'; |
| *--s = '<'; |
| ++*len; |
| } |
| // fixup for log signature split [, |
| // OPEN_BRACKET_SPACE is space, OPEN_BRACKET_SIG + <digit> |
| if ((*s & SIGNATURE_MASK) == OPEN_BRACKET_SIG) { |
| if (*s == OPEN_BRACKET_SPACE) { |
| *s = ' '; |
| } else { |
| *s = (*s & ~SIGNATURE_MASK) + '0'; |
| } |
| *--s = '['; |
| ++*len; |
| } |
| } |
| |
| while (*len && ((*s == '\r') || (*s == '\n'))) { |
| ++s; |
| --*len; |
| } |
| |
| if (!*len) { |
| *last = NULL; |
| return NULL; |
| } |
| char *peek, *tok = s; |
| |
| for (;;) { |
| if (*len == 0) { |
| *last = NULL; |
| return tok; |
| } |
| char c = *s++; |
| --*len; |
| size_t adjust; |
| switch (c) { |
| case '\r': |
| case '\n': |
| s[-1] = '\0'; |
| *last = s; |
| return tok; |
| |
| case '<': |
| peek = is_prio(s, *len); |
| if (!peek) { |
| break; |
| } |
| if (s != (tok + 1)) { // not first? |
| s[-1] = '\0'; |
| *s &= ~SIGNATURE_MASK; |
| *s |= LESS_THAN_SIG; // signature for '<' |
| *last = s; |
| return tok; |
| } |
| adjust = peek - s; |
| if (adjust > *len) { |
| adjust = *len; |
| } |
| *sublen += adjust; |
| *len -= adjust; |
| s = peek; |
| if ((*s == '[') && ((peek = is_timestamp(s + 1, *len - 1)))) { |
| adjust = peek - s; |
| if (adjust > *len) { |
| adjust = *len; |
| } |
| *sublen += adjust; |
| *len -= adjust; |
| s = peek; |
| } |
| break; |
| |
| case '[': |
| peek = is_timestamp(s, *len); |
| if (!peek) { |
| break; |
| } |
| if (s != (tok + 1)) { // not first? |
| s[-1] = '\0'; |
| if (*s == ' ') { |
| *s = OPEN_BRACKET_SPACE; |
| } else { |
| *s &= ~SIGNATURE_MASK; |
| *s |= OPEN_BRACKET_SIG; // signature for '[' |
| } |
| *last = s; |
| return tok; |
| } |
| adjust = peek - s; |
| if (adjust > *len) { |
| adjust = *len; |
| } |
| *sublen += adjust; |
| *len -= adjust; |
| s = peek; |
| break; |
| } |
| ++*sublen; |
| } |
| // NOTREACHED |
| } |
| |
| log_time LogKlog::correction = log_time(CLOCK_REALTIME) - log_time(CLOCK_MONOTONIC); |
| |
| LogKlog::LogKlog(LogBuffer *buf, LogReader *reader, int fdWrite, int fdRead, bool auditd) : |
| SocketListener(fdRead, false), |
| logbuf(buf), |
| reader(reader), |
| signature(CLOCK_MONOTONIC), |
| initialized(false), |
| enableLogging(true), |
| auditd(auditd) { |
| static const char klogd_message[] = "%slogd.klogd: %" PRIu64 "\n"; |
| char buffer[sizeof(priority_message) + sizeof(klogd_message) + 20 - 4]; |
| snprintf(buffer, sizeof(buffer), klogd_message, priority_message, |
| signature.nsec()); |
| write(fdWrite, buffer, strlen(buffer)); |
| } |
| |
| bool LogKlog::onDataAvailable(SocketClient *cli) { |
| if (!initialized) { |
| prctl(PR_SET_NAME, "logd.klogd"); |
| initialized = true; |
| enableLogging = false; |
| } |
| |
| char buffer[LOGGER_ENTRY_MAX_PAYLOAD]; |
| size_t len = 0; |
| |
| for(;;) { |
| ssize_t retval = 0; |
| if ((sizeof(buffer) - 1 - len) > 0) { |
| retval = read(cli->getSocket(), buffer + len, sizeof(buffer) - 1 - len); |
| } |
| if ((retval == 0) && (len == 0)) { |
| break; |
| } |
| if (retval < 0) { |
| return false; |
| } |
| len += retval; |
| bool full = len == (sizeof(buffer) - 1); |
| char *ep = buffer + len; |
| *ep = '\0'; |
| size_t sublen; |
| for(char *ptr = NULL, *tok = buffer; |
| ((tok = log_strntok_r(tok, &len, &ptr, &sublen))); |
| tok = NULL) { |
| if (((tok + sublen) >= ep) && (retval != 0) && full) { |
| memmove(buffer, tok, sublen); |
| len = sublen; |
| break; |
| } |
| if (*tok) { |
| log(tok, sublen); |
| } |
| } |
| } |
| |
| return true; |
| } |
| |
| |
| void LogKlog::calculateCorrection(const log_time &monotonic, |
| const char *real_string, |
| size_t len) { |
| log_time real; |
| const char *ep = real.strptime(real_string, "%Y-%m-%d %H:%M:%S.%09q UTC"); |
| if (!ep || (ep > &real_string[len])) { |
| return; |
| } |
| // kernel report UTC, log_time::strptime is localtime from calendar. |
| // Bionic and liblog strptime does not support %z or %Z to pick up |
| // timezone so we are calculating our own correction. |
| time_t now = real.tv_sec; |
| struct tm tm; |
| memset(&tm, 0, sizeof(tm)); |
| tm.tm_isdst = -1; |
| localtime_r(&now, &tm); |
| real.tv_sec += tm.tm_gmtoff; |
| correction = real - monotonic; |
| } |
| |
| static const char suspendStr[] = "PM: suspend entry "; |
| static const char resumeStr[] = "PM: suspend exit "; |
| static const char suspendedStr[] = "Suspended for "; |
| |
| static const char *strnstr(const char *s, size_t len, const char *needle) { |
| char c; |
| |
| if (!len) { |
| return NULL; |
| } |
| if ((c = *needle++) != 0) { |
| size_t needleLen = strlen(needle); |
| do { |
| do { |
| if (len <= needleLen) { |
| return NULL; |
| } |
| --len; |
| } while (*s++ != c); |
| } while (fast<memcmp>(s, needle, needleLen)); |
| s--; |
| } |
| return s; |
| } |
| |
| void LogKlog::sniffTime(log_time &now, |
| const char **buf, size_t len, |
| bool reverse) { |
| const char *cp = now.strptime(*buf, "[ %s.%q]"); |
| if (cp && (cp >= &(*buf)[len])) { |
| cp = NULL; |
| } |
| len -= cp - *buf; |
| if (cp) { |
| static const char healthd[] = "healthd"; |
| static const char battery[] = ": battery "; |
| |
| if (len && isspace(*cp)) { |
| ++cp; |
| --len; |
| } |
| *buf = cp; |
| |
| if (isMonotonic()) { |
| return; |
| } |
| |
| const char *b; |
| if (((b = strnstr(cp, len, suspendStr))) |
| && ((size_t)((b += sizeof(suspendStr) - 1) - cp) < len)) { |
| len -= b - cp; |
| calculateCorrection(now, b, len); |
| } else if (((b = strnstr(cp, len, resumeStr))) |
| && ((size_t)((b += sizeof(resumeStr) - 1) - cp) < len)) { |
| len -= b - cp; |
| calculateCorrection(now, b, len); |
| } else if (((b = strnstr(cp, len, healthd))) |
| && ((size_t)((b += sizeof(healthd) - 1) - cp) < len) |
| && ((b = strnstr(b, len -= b - cp, battery))) |
| && ((size_t)((b += sizeof(battery) - 1) - cp) < len)) { |
| len -= b - cp; |
| // NB: healthd is roughly 150us late, worth the price to deal with |
| // ntp-induced or hardware clock drift. |
| // look for " 2???-??-?? ??:??:??.????????? ???" |
| for (; len && *b && (*b != '\n'); ++b, --len) { |
| if ((b[0] == ' ') && (b[1] == '2') && (b[5] == '-')) { |
| calculateCorrection(now, b + 1, len - 1); |
| break; |
| } |
| } |
| } else if (((b = strnstr(cp, len, suspendedStr))) |
| && ((size_t)((b += sizeof(suspendStr) - 1) - cp) < len)) { |
| len -= b - cp; |
| log_time real; |
| char *endp; |
| real.tv_sec = strtol(b, &endp, 10); |
| if ((*endp == '.') && ((size_t)(endp - b) < len)) { |
| unsigned long multiplier = NS_PER_SEC; |
| real.tv_nsec = 0; |
| len -= endp - b; |
| while (--len && isdigit(*++endp) && (multiplier /= 10)) { |
| real.tv_nsec += (*endp - '0') * multiplier; |
| } |
| if (reverse) { |
| correction -= real; |
| } else { |
| correction += real; |
| } |
| } |
| } |
| |
| convertMonotonicToReal(now); |
| } else { |
| if (isMonotonic()) { |
| now = log_time(CLOCK_MONOTONIC); |
| } else { |
| now = log_time(CLOCK_REALTIME); |
| } |
| } |
| } |
| |
| pid_t LogKlog::sniffPid(const char *cp, size_t len) { |
| while (len) { |
| // Mediatek kernels with modified printk |
| if (*cp == '[') { |
| int pid = 0; |
| char dummy; |
| if (sscanf(cp, "[%d:%*[a-z_./0-9:A-Z]]%c", &pid, &dummy) == 2) { |
| return pid; |
| } |
| break; // Only the first one |
| } |
| ++cp; |
| --len; |
| } |
| return 0; |
| } |
| |
| // kernel log prefix, convert to a kernel log priority number |
| static int parseKernelPrio(const char **buf, size_t len) { |
| int pri = LOG_USER | LOG_INFO; |
| const char *cp = *buf; |
| if (len && (*cp == '<')) { |
| pri = 0; |
| while(--len && isdigit(*++cp)) { |
| pri = (pri * 10) + *cp - '0'; |
| } |
| if (len && (*cp == '>')) { |
| ++cp; |
| } else { |
| cp = *buf; |
| pri = LOG_USER | LOG_INFO; |
| } |
| *buf = cp; |
| } |
| return pri; |
| } |
| |
| // Passed the entire SYSLOG_ACTION_READ_ALL buffer and interpret a |
| // compensated start time. |
| void LogKlog::synchronize(const char *buf, size_t len) { |
| const char *cp = strnstr(buf, len, suspendStr); |
| if (!cp) { |
| cp = strnstr(buf, len, resumeStr); |
| if (!cp) { |
| return; |
| } |
| } else { |
| const char *rp = strnstr(buf, len, resumeStr); |
| if (rp && (rp < cp)) { |
| cp = rp; |
| } |
| } |
| |
| do { |
| --cp; |
| } while ((cp > buf) && (*cp != '\n')); |
| if (*cp == '\n') { |
| ++cp; |
| } |
| parseKernelPrio(&cp, len - (cp - buf)); |
| |
| log_time now; |
| sniffTime(now, &cp, len - (cp - buf), true); |
| |
| const char *suspended = strnstr(buf, len, suspendedStr); |
| if (!suspended || (suspended > cp)) { |
| return; |
| } |
| cp = suspended; |
| |
| do { |
| --cp; |
| } while ((cp > buf) && (*cp != '\n')); |
| if (*cp == '\n') { |
| ++cp; |
| } |
| parseKernelPrio(&cp, len - (cp - buf)); |
| |
| sniffTime(now, &cp, len - (cp - buf), true); |
| } |
| |
| // Convert kernel log priority number into an Android Logger priority number |
| static int convertKernelPrioToAndroidPrio(int pri) { |
| switch(pri & LOG_PRIMASK) { |
| case LOG_EMERG: |
| // FALLTHRU |
| case LOG_ALERT: |
| // FALLTHRU |
| case LOG_CRIT: |
| return ANDROID_LOG_FATAL; |
| |
| case LOG_ERR: |
| return ANDROID_LOG_ERROR; |
| |
| case LOG_WARNING: |
| return ANDROID_LOG_WARN; |
| |
| default: |
| // FALLTHRU |
| case LOG_NOTICE: |
| // FALLTHRU |
| case LOG_INFO: |
| break; |
| |
| case LOG_DEBUG: |
| return ANDROID_LOG_DEBUG; |
| } |
| |
| return ANDROID_LOG_INFO; |
| } |
| |
| static const char *strnrchr(const char *s, size_t len, char c) { |
| const char *save = NULL; |
| for (;len; ++s, len--) { |
| if (*s == c) { |
| save = s; |
| } |
| } |
| return save; |
| } |
| |
| // |
| // log a message into the kernel log buffer |
| // |
| // Filter rules to parse <PRI> <TIME> <tag> and <message> in order for |
| // them to appear correct in the logcat output: |
| // |
| // LOG_KERN (0): |
| // <PRI>[<TIME>] <tag> ":" <message> |
| // <PRI>[<TIME>] <tag> <tag> ":" <message> |
| // <PRI>[<TIME>] <tag> <tag>_work ":" <message> |
| // <PRI>[<TIME>] <tag> '<tag>.<num>' ":" <message> |
| // <PRI>[<TIME>] <tag> '<tag><num>' ":" <message> |
| // <PRI>[<TIME>] <tag>_host '<tag>.<num>' ":" <message> |
| // (unimplemented) <PRI>[<TIME>] <tag> '<num>.<tag>' ":" <message> |
| // <PRI>[<TIME>] "[INFO]"<tag> : <message> |
| // <PRI>[<TIME>] "------------[ cut here ]------------" (?) |
| // <PRI>[<TIME>] "---[ end trace 3225a3070ca3e4ac ]---" (?) |
| // LOG_USER, LOG_MAIL, LOG_DAEMON, LOG_AUTH, LOG_SYSLOG, LOG_LPR, LOG_NEWS |
| // LOG_UUCP, LOG_CRON, LOG_AUTHPRIV, LOG_FTP: |
| // <PRI+TAG>[<TIME>] (see sys/syslog.h) |
| // Observe: |
| // Minimum tag length = 3 NB: drops things like r5:c00bbadf, but allow PM: |
| // Maximum tag words = 2 |
| // Maximum tag length = 16 NB: we are thinking of how ugly logcat can get. |
| // Not a Tag if there is no message content. |
| // leading additional spaces means no tag, inherit last tag. |
| // Not a Tag if <tag>: is "ERROR:", "WARNING:", "INFO:" or "CPU:" |
| // Drop: |
| // empty messages |
| // messages with ' audit(' in them if auditd is running |
| // logd.klogd: |
| // return -1 if message logd.klogd: <signature> |
| // |
| int LogKlog::log(const char *buf, size_t len) { |
| if (auditd && strnstr(buf, len, " audit(")) { |
| return 0; |
| } |
| |
| const char *p = buf; |
| int pri = parseKernelPrio(&p, len); |
| |
| log_time now; |
| sniffTime(now, &p, len - (p - buf), false); |
| |
| // sniff for start marker |
| const char klogd_message[] = "logd.klogd: "; |
| const char *start = strnstr(p, len - (p - buf), klogd_message); |
| if (start) { |
| uint64_t sig = strtoll(start + sizeof(klogd_message) - 1, NULL, 10); |
| if (sig == signature.nsec()) { |
| if (initialized) { |
| enableLogging = true; |
| } else { |
| enableLogging = false; |
| } |
| return -1; |
| } |
| return 0; |
| } |
| |
| if (!enableLogging) { |
| return 0; |
| } |
| |
| // Parse pid, tid and uid |
| const pid_t pid = sniffPid(p, len - (p - buf)); |
| const pid_t tid = pid; |
| const uid_t uid = pid ? logbuf->pidToUid(pid) : 0; |
| |
| // Parse (rules at top) to pull out a tag from the incoming kernel message. |
| // Some may view the following as an ugly heuristic, the desire is to |
| // beautify the kernel logs into an Android Logging format; the goal is |
| // admirable but costly. |
| while ((p < &buf[len]) && (isspace(*p) || !*p)) { |
| ++p; |
| } |
| if (p >= &buf[len]) { // timestamp, no content |
| return 0; |
| } |
| start = p; |
| const char *tag = ""; |
| const char *etag = tag; |
| size_t taglen = len - (p - buf); |
| if (!isspace(*p) && *p) { |
| const char *bt, *et, *cp; |
| |
| bt = p; |
| if ((taglen >= 6) && !fast<strncmp>(p, "[INFO]", 6)) { |
| // <PRI>[<TIME>] "[INFO]"<tag> ":" message |
| bt = p + 6; |
| taglen -= 6; |
| } |
| for(et = bt; taglen && *et && (*et != ':') && !isspace(*et); ++et, --taglen) { |
| // skip ':' within [ ... ] |
| if (*et == '[') { |
| while (taglen && *et && *et != ']') { |
| ++et; |
| --taglen; |
| } |
| } |
| } |
| for(cp = et; taglen && isspace(*cp); ++cp, --taglen); |
| size_t size; |
| |
| if (*cp == ':') { |
| // One Word |
| tag = bt; |
| etag = et; |
| p = cp + 1; |
| } else if (taglen) { |
| size = et - bt; |
| if ((taglen > size) && // enough space for match plus trailing : |
| (*bt == *cp) && // ubber fast<strncmp> pair |
| fast<strncmp>(bt + 1, cp + 1, size - 1)) { |
| // <PRI>[<TIME>] <tag>_host '<tag>.<num>' : message |
| if (!fast<strncmp>(bt + size - 5, "_host", 5) |
| && !fast<strncmp>(bt + 1, cp + 1, size - 6)) { |
| const char *b = cp; |
| cp += size - 5; |
| taglen -= size - 5; |
| if (*cp == '.') { |
| while (--taglen && !isspace(*++cp) && (*cp != ':')); |
| const char *e; |
| for(e = cp; taglen && isspace(*cp); ++cp, --taglen); |
| if (*cp == ':') { |
| tag = b; |
| etag = e; |
| p = cp + 1; |
| } |
| } |
| } else { |
| while (--taglen && !isspace(*++cp) && (*cp != ':')); |
| const char *e; |
| for(e = cp; taglen && isspace(*cp); ++cp, --taglen); |
| // Two words |
| if (*cp == ':') { |
| tag = bt; |
| etag = e; |
| p = cp + 1; |
| } |
| } |
| } else if (isspace(cp[size])) { |
| cp += size; |
| taglen -= size; |
| while (--taglen && isspace(*++cp)); |
| // <PRI>[<TIME>] <tag> <tag> : message |
| if (*cp == ':') { |
| tag = bt; |
| etag = et; |
| p = cp + 1; |
| } |
| } else if (cp[size] == ':') { |
| // <PRI>[<TIME>] <tag> <tag> : message |
| tag = bt; |
| etag = et; |
| p = cp + size + 1; |
| } else if ((cp[size] == '.') || isdigit(cp[size])) { |
| // <PRI>[<TIME>] <tag> '<tag>.<num>' : message |
| // <PRI>[<TIME>] <tag> '<tag><num>' : message |
| const char *b = cp; |
| cp += size; |
| taglen -= size; |
| while (--taglen && !isspace(*++cp) && (*cp != ':')); |
| const char *e = cp; |
| while (taglen && isspace(*cp)) { |
| ++cp; |
| --taglen; |
| } |
| if (*cp == ':') { |
| tag = b; |
| etag = e; |
| p = cp + 1; |
| } |
| } else { |
| while (--taglen && !isspace(*++cp) && (*cp != ':')); |
| const char *e = cp; |
| while (taglen && isspace(*cp)) { |
| ++cp; |
| --taglen; |
| } |
| // Two words |
| if (*cp == ':') { |
| tag = bt; |
| etag = e; |
| p = cp + 1; |
| } |
| } |
| } /* else no tag */ |
| size = etag - tag; |
| if ((size <= 1) |
| // register names like x9 |
| || ((size == 2) && (isdigit(tag[0]) || isdigit(tag[1]))) |
| // register names like x18 but not driver names like en0 |
| || ((size == 3) && (isdigit(tag[1]) && isdigit(tag[2]))) |
| // blacklist |
| || ((size == 3) && !fast<strncmp>(tag, "CPU", 3)) |
| || ((size == 7) && !fast<strncasecmp>(tag, "WARNING", 7)) |
| || ((size == 5) && !fast<strncasecmp>(tag, "ERROR", 5)) |
| || ((size == 4) && !fast<strncasecmp>(tag, "INFO", 4))) { |
| p = start; |
| etag = tag = ""; |
| } |
| } |
| // Suppress additional stutter in tag: |
| // eg: [143:healthd]healthd -> [143:healthd] |
| taglen = etag - tag; |
| // Mediatek-special printk induced stutter |
| const char *mp = strnrchr(tag, ']', taglen); |
| if (mp && (++mp < etag)) { |
| size_t s = etag - mp; |
| if (((s + s) < taglen) && !fast<memcmp>(mp, mp - 1 - s, s)) { |
| taglen = mp - tag; |
| } |
| } |
| // Deal with sloppy and simplistic harmless p = cp + 1 etc above. |
| if (len < (size_t)(p - buf)) { |
| p = &buf[len]; |
| } |
| // skip leading space |
| while ((p < &buf[len]) && (isspace(*p) || !*p)) { |
| ++p; |
| } |
| // truncate trailing space or nuls |
| size_t b = len - (p - buf); |
| while (b && (isspace(p[b-1]) || !p[b-1])) { |
| --b; |
| } |
| // trick ... allow tag with empty content to be logged. log() drops empty |
| if (!b && taglen) { |
| p = " "; |
| b = 1; |
| } |
| // paranoid sanity check, can not happen ... |
| if (b > LOGGER_ENTRY_MAX_PAYLOAD) { |
| b = LOGGER_ENTRY_MAX_PAYLOAD; |
| } |
| if (taglen > LOGGER_ENTRY_MAX_PAYLOAD) { |
| taglen = LOGGER_ENTRY_MAX_PAYLOAD; |
| } |
| // calculate buffer copy requirements |
| size_t n = 1 + taglen + 1 + b + 1; |
| // paranoid sanity check, first two just can not happen ... |
| if ((taglen > n) || (b > n) || (n > USHRT_MAX)) { |
| return -EINVAL; |
| } |
| |
| // Careful. |
| // We are using the stack to house the log buffer for speed reasons. |
| // If we malloc'd this buffer, we could get away without n's USHRT_MAX |
| // test above, but we would then required a max(n, USHRT_MAX) as |
| // truncating length argument to logbuf->log() below. Gain is protection |
| // of stack sanity and speedup, loss is truncated long-line content. |
| char newstr[n]; |
| char *np = newstr; |
| |
| // Convert priority into single-byte Android logger priority |
| *np = convertKernelPrioToAndroidPrio(pri); |
| ++np; |
| |
| // Copy parsed tag following priority |
| memcpy(np, tag, taglen); |
| np += taglen; |
| *np = '\0'; |
| ++np; |
| |
| // Copy main message to the remainder |
| memcpy(np, p, b); |
| np[b] = '\0'; |
| |
| if (!isMonotonic()) { |
| // Watch out for singular race conditions with timezone causing near |
| // integer quarter-hour jumps in the time and compensate accordingly. |
| // Entries will be temporal within near_seconds * 2. b/21868540 |
| static uint32_t vote_time[3]; |
| vote_time[2] = vote_time[1]; |
| vote_time[1] = vote_time[0]; |
| vote_time[0] = now.tv_sec; |
| |
| if (vote_time[1] && vote_time[2]) { |
| static const unsigned near_seconds = 10; |
| static const unsigned timezones_seconds = 900; |
| int diff0 = (vote_time[0] - vote_time[1]) / near_seconds; |
| unsigned abs0 = (diff0 < 0) ? -diff0 : diff0; |
| int diff1 = (vote_time[1] - vote_time[2]) / near_seconds; |
| unsigned abs1 = (diff1 < 0) ? -diff1 : diff1; |
| if ((abs1 <= 1) && // last two were in agreement on timezone |
| ((abs0 + 1) % (timezones_seconds / near_seconds)) <= 2) { |
| abs0 = (abs0 + 1) / (timezones_seconds / near_seconds) * |
| timezones_seconds; |
| now.tv_sec -= (diff0 < 0) ? -abs0 : abs0; |
| } |
| } |
| } |
| |
| // Log message |
| int rc = logbuf->log(LOG_ID_KERNEL, now, uid, pid, tid, newstr, |
| (unsigned short) n); |
| |
| // notify readers |
| if (!rc) { |
| reader->notifyNewLog(); |
| } |
| |
| return rc; |
| } |
