c84520d73
Denis Vlasenko
2007-02-17
Subject
klogd: code de-obfuscation with small code size reduction
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Commit Diff GitHub →
include/libbb.h+1 -0
| @@ -271,6 +271,7 @@ extern void xdaemon(int nochdir, int noclose); | |
| /* More clever/thorough xdaemon */ | |
| extern void bb_sanitize_stdio_maybe_daemonize(int daemonize); | |
| extern void bb_sanitize_stdio(void); | |
| + | /* NB: be careful: dont open syslog/network sockets before bb_daemonize */ |
| extern void bb_daemonize(void); | |
| extern void xchdir(const char *path); | |
| extern void xsetenv(const char *key, const char *value); | |
sysklogd/klogd.c+20 -25
| @@ -32,12 +32,12 @@ static void klogd_signal(int sig ATTRIBUTE_UNUSED) | |
| #define OPT_LEVEL 1 | |
| #define OPT_FOREGROUND 2 | |
| - | #define KLOGD_LOGBUF_SIZE 4096 |
| + | #define KLOGD_LOGBUF_SIZE BUFSIZ |
| + | #define log_buffer bb_common_bufsiz1 |
| int klogd_main(int argc, char **argv); | |
| int klogd_main(int argc, char **argv) | |
| { | |
| - | RESERVE_CONFIG_BUFFER(log_buffer, KLOGD_LOGBUF_SIZE); |
| int i = i; /* silence gcc */ | |
| char *start; | |
| @@ -53,7 +53,7 @@ int klogd_main(int argc, char **argv) | |
| #ifdef BB_NOMMU | |
| vfork_daemon_rexec(0, 1, argc, argv, "-n"); | |
| #else | |
| - | xdaemon(0, 1); |
| + | bb_daemonize(); |
| #endif | |
| } | |
| @@ -68,35 +68,34 @@ int klogd_main(int argc, char **argv) | |
| /* "Open the log. Currently a NOP." */ | |
| klogctl(1, NULL, 0); | |
| - | /* Set level of kernel console messaging.. */ |
| + | /* Set level of kernel console messaging. */ |
| if (option_mask32 & OPT_LEVEL) | |
| klogctl(8, NULL, i); | |
| syslog(LOG_NOTICE, "klogd started: %s", BB_BANNER); | |
| + | /* Note: this code does not detect incomplete messages |
| + | * (messages not ending with '\n' or just when kernel |
| + | * generates too many messages for us to keep up) |
| + | * and will split them in two separate lines */ |
| while (1) { | |
| int n; | |
| int priority; | |
| - | char lastc; |
| - | /* Use kernel syscalls */ |
| - | memset(log_buffer, '\0', KLOGD_LOGBUF_SIZE); |
| - | /* It will be null-terminted */ |
| n = klogctl(2, log_buffer, KLOGD_LOGBUF_SIZE - 1); | |
| if (n < 0) { | |
| if (errno == EINTR) | |
| continue; | |
| syslog(LOG_ERR, "klogd: error from klogctl(2): %d - %m", | |
| - | errno); |
| + | errno); |
| break; | |
| } | |
| - | |
| - | /* klogctl buffer parsing modelled after code in dmesg.c */ |
| - | start = &log_buffer[0]; |
| - | lastc = '\0'; |
| - | priority = LOG_INFO; |
| - | for (i = 0; i < n; i++) { |
| - | if (lastc == '\0' && log_buffer[i] == '<') { |
| + | log_buffer[n] = '\n'; |
| + | i = 0; |
| + | while (i < n) { |
| + | priority = LOG_INFO; |
| + | start = &log_buffer[i]; |
| + | if (log_buffer[i] == '<') { |
| i++; | |
| // kernel never ganerates multi-digit prios | |
| //priority = 0; | |
| @@ -112,17 +111,13 @@ int klogd_main(int argc, char **argv) | |
| i++; | |
| start = &log_buffer[i]; | |
| } | |
| - | if (log_buffer[i] == '\n') { |
| - | log_buffer[i] = '\0'; /* zero terminate this message */ |
| - | syslog(priority, "%s", start); |
| - | start = &log_buffer[i + 1]; |
| - | priority = LOG_INFO; |
| - | } |
| - | lastc = log_buffer[i]; |
| + | while (log_buffer[i] != '\n') |
| + | i++; |
| + | log_buffer[i] = '\0'; |
| + | syslog(priority, "%s", start); |
| + | i++; |
| } | |
| } | |
| - | if (ENABLE_FEATURE_CLEAN_UP) |
| - | RELEASE_CONFIG_BUFFER(log_buffer); |
| return EXIT_FAILURE; | |
| } | |