diff options
Diffstat (limited to 'lib/mlibc/options/posix/generic/syslog-stubs.cpp')
| -rw-r--r-- | lib/mlibc/options/posix/generic/syslog-stubs.cpp | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/lib/mlibc/options/posix/generic/syslog-stubs.cpp b/lib/mlibc/options/posix/generic/syslog-stubs.cpp new file mode 100644 index 0000000..6a80ff9 --- /dev/null +++ b/lib/mlibc/options/posix/generic/syslog-stubs.cpp @@ -0,0 +1,152 @@ + +#include <syslog.h> +#include <string.h> +#include <unistd.h> +#include <stdio.h> +#include <errno.h> +#include <time.h> +#include <fcntl.h> +#include <pthread.h> +#include <sys/socket.h> +#include <sys/un.h> +#include <bits/ensure.h> + +#include <frg/mutex.hpp> +#include <mlibc/lock.hpp> +#include <mlibc/debug.hpp> + +// This syslog implementation is largely taken from musl + +static char log_ident[32]; +static int log_options; +static int log_facility = LOG_USER; +static int log_fd = -1; +static int log_opt; +static int log_mask = 0xff; + +static int use_mlibc_logger = 0; +static FutexLock __syslog_lock; + +static const struct sockaddr_un log_addr {AF_UNIX, "/dev/log"}; + +void closelog(void) { + frg::unique_lock<FutexLock> holder { __syslog_lock }; + close(log_fd); + log_fd = -1; +} + +static void __openlog() { + log_fd = socket(AF_UNIX, SOCK_DGRAM | SOCK_CLOEXEC, 0); + if(log_fd >= 0) { + int ret = connect(log_fd, (const sockaddr *)&log_addr, sizeof log_addr); + if(ret) { + mlibc::infoLogger() << "\e[31mmlibc: syslog: connect returned an error, falling back to infoLogger\e[39m" << frg::endlog; + use_mlibc_logger = 1; + } + } +} + +void openlog(const char *ident, int options, int facility) { + frg::unique_lock<FutexLock> holder { __syslog_lock }; + if(ident) { + size_t n = strnlen(ident, sizeof log_ident - 1); + memcpy(log_ident, ident, n); + log_ident[n] = 0; + } else { + log_ident[0] = 0; + } + log_options = options; + log_facility = facility; + + if((options & LOG_NDELAY) && log_fd < 0) + __openlog(); +} + +int setlogmask(int mask) { + int old_mask = log_mask; + + log_mask = mask; + + return old_mask; +} + +static void _vsyslog(int priority, const char *message, va_list ap) { + auto is_lost_conn = [] (int e) { + return e == ECONNREFUSED || e == ECONNRESET || e == ENOTCONN || e == EPIPE; + }; + + if(!(priority & log_mask)) { + return; + } + + char timebuf[16]; + time_t now; + struct tm tm; + char buf[1024]; + int errno_save = errno; + int pid; + int l, l2; + int hlen; + int fd; + + if(log_fd < 0) + __openlog(); + + if(use_mlibc_logger) { + vsnprintf(buf, sizeof buf, message, ap); + mlibc::infoLogger() << "mlibc: syslog: " << buf << frg::endlog; + return; + } + + if(!(priority & LOG_FACMASK)) + priority |= log_facility; + + now = time(NULL); + gmtime_r(&now, &tm); + strftime(timebuf, sizeof timebuf, "%b %e %T", &tm); + + pid = (log_opt & LOG_PID) ? getpid() : 0; + l = snprintf(buf, sizeof buf, "<%d>%s %n%s%s%.0d%s: ", + priority, timebuf, &hlen, log_ident, "[" + !pid, pid, "]" + !pid); + errno = errno_save; + l2 = vsnprintf(buf + l, sizeof buf - l, message, ap); + if(l2 >= 0) { + if(l2 >= (long int)(sizeof buf - l)) + l = sizeof buf - 1; + else + l += l2; + if(buf[l - 1] != '\n') + buf[l++] = '\n'; + if(send(log_fd, buf, l, 0) < 0 && (!is_lost_conn(errno) + || connect(log_fd, (const sockaddr *)&log_addr, sizeof log_addr) < 0 + || send(log_fd, buf, l, 0) < 0) + && (log_opt & LOG_CONS)) { + fd = open("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC); + if(fd >= 0) { + dprintf(fd, "%.*s", l - hlen, buf + hlen); + close(fd); + } + } + if(log_opt & LOG_PERROR) + dprintf(STDERR_FILENO, "%.*s", l - hlen, buf + hlen); + } +} + +void syslog(int priority, const char *format, ...) { + va_list ap; + va_start(ap, format); + vsyslog(priority, format, ap); + va_end(ap); +} + +void vsyslog(int priority, const char *message, va_list ap) { + int cs; + if(!(log_mask & LOG_MASK(priority & 7)) || (priority & ~0x3ff)) { + mlibc::infoLogger() << "\e[31mmlibc: syslog: log_mask or priority out of range, not printing anything\e[39m" << frg::endlog; + return; + } + pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs); + frg::unique_lock<FutexLock> lock(__syslog_lock); + _vsyslog(priority, message, ap); + pthread_setcancelstate(cs, 0); +} |