diff options
Diffstat (limited to 'extensions/libxt_LOG.c')
| -rw-r--r-- | extensions/libxt_LOG.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/extensions/libxt_LOG.c b/extensions/libxt_LOG.c new file mode 100644 index 00000000..b6fe0b2e --- /dev/null +++ b/extensions/libxt_LOG.c @@ -0,0 +1,204 @@ +#include <stdio.h> +#include <string.h> +#define SYSLOG_NAMES +#include <syslog.h> +#include <xtables.h> +#include <linux/netfilter/xt_LOG.h> + +#define LOG_DEFAULT_LEVEL LOG_WARNING + +enum { + /* make sure the values correspond with XT_LOG_* bit positions */ + O_LOG_TCPSEQ = 0, + O_LOG_TCPOPTS, + O_LOG_IPOPTS, + O_LOG_UID, + __O_LOG_NFLOG, + O_LOG_MAC, + O_LOG_LEVEL, + O_LOG_PREFIX, +}; + +static void LOG_help(void) +{ + printf( +"LOG target options:\n" +" --log-level level Level of logging (numeric or see syslog.conf)\n" +" --log-prefix prefix Prefix log messages with this prefix.\n" +" --log-tcp-sequence Log TCP sequence numbers.\n" +" --log-tcp-options Log TCP options.\n" +" --log-ip-options Log IP options.\n" +" --log-uid Log UID owning the local socket.\n" +" --log-macdecode Decode MAC addresses and protocol.\n"); +} + +#define s struct xt_log_info +static const struct xt_option_entry LOG_opts[] = { + {.name = "log-level", .id = O_LOG_LEVEL, .type = XTTYPE_SYSLOGLEVEL, + .flags = XTOPT_PUT, XTOPT_POINTER(s, level)}, + {.name = "log-prefix", .id = O_LOG_PREFIX, .type = XTTYPE_STRING, + .flags = XTOPT_PUT, XTOPT_POINTER(s, prefix), .min = 1}, + {.name = "log-tcp-sequence", .id = O_LOG_TCPSEQ, .type = XTTYPE_NONE}, + {.name = "log-tcp-options", .id = O_LOG_TCPOPTS, .type = XTTYPE_NONE}, + {.name = "log-ip-options", .id = O_LOG_IPOPTS, .type = XTTYPE_NONE}, + {.name = "log-uid", .id = O_LOG_UID, .type = XTTYPE_NONE}, + {.name = "log-macdecode", .id = O_LOG_MAC, .type = XTTYPE_NONE}, + XTOPT_TABLEEND, +}; +#undef s + +static void LOG_init(struct xt_entry_target *t) +{ + struct xt_log_info *loginfo = (void *)t->data; + + loginfo->level = LOG_DEFAULT_LEVEL; +} + +static void LOG_parse(struct xt_option_call *cb) +{ + struct xt_log_info *info = cb->data; + + xtables_option_parse(cb); + switch (cb->entry->id) { + case O_LOG_PREFIX: + if (strchr(cb->arg, '\n') != NULL) + xtables_error(PARAMETER_PROBLEM, + "Newlines not allowed in --log-prefix"); + break; + case O_LOG_TCPSEQ: + case O_LOG_TCPOPTS: + case O_LOG_IPOPTS: + case O_LOG_UID: + case O_LOG_MAC: + info->logflags |= 1 << cb->entry->id; + break; + } +} + +static const char *priority2name(unsigned char level) +{ + int i; + + for (i = 0; prioritynames[i].c_name; ++i) { + if (level == prioritynames[i].c_val) + return prioritynames[i].c_name; + } + return NULL; +} + +static void LOG_print(const void *ip, const struct xt_entry_target *target, + int numeric) +{ + const struct xt_log_info *loginfo = (const void *)target->data; + + printf(" LOG"); + if (numeric) + printf(" flags %u level %u", + loginfo->logflags, loginfo->level); + else { + const char *pname = priority2name(loginfo->level); + + if (pname) + printf(" level %s", pname); + else + printf(" UNKNOWN level %u", loginfo->level); + if (loginfo->logflags & XT_LOG_TCPSEQ) + printf(" tcp-sequence"); + if (loginfo->logflags & XT_LOG_TCPOPT) + printf(" tcp-options"); + if (loginfo->logflags & XT_LOG_IPOPT) + printf(" ip-options"); + if (loginfo->logflags & XT_LOG_UID) + printf(" uid"); + if (loginfo->logflags & XT_LOG_MACDECODE) + printf(" macdecode"); + if (loginfo->logflags & ~(XT_LOG_MASK)) + printf(" unknown-flags"); + } + + if (strcmp(loginfo->prefix, "") != 0) + printf(" prefix \"%s\"", loginfo->prefix); +} + +static void LOG_save(const void *ip, const struct xt_entry_target *target) +{ + const struct xt_log_info *loginfo = (const void *)target->data; + + if (strcmp(loginfo->prefix, "") != 0) { + printf(" --log-prefix"); + xtables_save_string(loginfo->prefix); + } + + if (loginfo->level != LOG_DEFAULT_LEVEL) + printf(" --log-level %d", loginfo->level); + + if (loginfo->logflags & XT_LOG_TCPSEQ) + printf(" --log-tcp-sequence"); + if (loginfo->logflags & XT_LOG_TCPOPT) + printf(" --log-tcp-options"); + if (loginfo->logflags & XT_LOG_IPOPT) + printf(" --log-ip-options"); + if (loginfo->logflags & XT_LOG_UID) + printf(" --log-uid"); + if (loginfo->logflags & XT_LOG_MACDECODE) + printf(" --log-macdecode"); +} + +static int LOG_xlate(struct xt_xlate *xl, + const struct xt_xlate_tg_params *params) +{ + const struct xt_log_info *loginfo = (const void *)params->target->data; + const char *pname = priority2name(loginfo->level); + + xt_xlate_add(xl, "log"); + if (strcmp(loginfo->prefix, "") != 0) + xt_xlate_add(xl, " prefix \"%s\"", loginfo->prefix); + + if (loginfo->level != LOG_DEFAULT_LEVEL && pname) + xt_xlate_add(xl, " level %s", pname); + else if (!pname) + return 0; + + if ((loginfo->logflags & XT_LOG_MASK) == XT_LOG_MASK) { + xt_xlate_add(xl, " flags all"); + } else { + if (loginfo->logflags & (XT_LOG_TCPSEQ | XT_LOG_TCPOPT)) { + const char *delim = " "; + + xt_xlate_add(xl, " flags tcp"); + if (loginfo->logflags & XT_LOG_TCPSEQ) { + xt_xlate_add(xl, " sequence"); + delim = ","; + } + if (loginfo->logflags & XT_LOG_TCPOPT) + xt_xlate_add(xl, "%soptions", delim); + } + if (loginfo->logflags & XT_LOG_IPOPT) + xt_xlate_add(xl, " flags ip options"); + if (loginfo->logflags & XT_LOG_UID) + xt_xlate_add(xl, " flags skuid"); + if (loginfo->logflags & XT_LOG_MACDECODE) + xt_xlate_add(xl, " flags ether"); + } + + return 1; +} +static struct xtables_target log_tg_reg = { + .name = "LOG", + .version = XTABLES_VERSION, + .family = NFPROTO_UNSPEC, + .size = XT_ALIGN(sizeof(struct xt_log_info)), + .userspacesize = XT_ALIGN(sizeof(struct xt_log_info)), + .help = LOG_help, + .init = LOG_init, + .print = LOG_print, + .save = LOG_save, + .x6_parse = LOG_parse, + .x6_options = LOG_opts, + .xlate = LOG_xlate, +}; + +void _init(void) +{ + xtables_register_target(&log_tg_reg); +} |