diff options
Diffstat (limited to 'extensions/libipt_LOG.c')
| -rw-r--r-- | extensions/libipt_LOG.c | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/extensions/libipt_LOG.c b/extensions/libipt_LOG.c new file mode 100644 index 0000000..9afb91d --- /dev/null +++ b/extensions/libipt_LOG.c @@ -0,0 +1,264 @@ +/* Shared library add-on to iptables to add LOG support. */ +#include <stdio.h> +#include <netdb.h> +#include <string.h> +#include <stdlib.h> +#include <syslog.h> +#include <getopt.h> +#include <xtables.h> +#include <linux/netfilter_ipv4/ipt_LOG.h> + +#define LOG_DEFAULT_LEVEL LOG_WARNING + +#ifndef IPT_LOG_UID /* Old kernel */ +#define IPT_LOG_UID 0x08 /* Log UID owning local socket */ +#undef IPT_LOG_MASK +#define IPT_LOG_MASK 0x0f +#endif + +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\n" +" --log-tcp-sequence Log TCP sequence numbers.\n\n" +" --log-tcp-options Log TCP options.\n\n" +" --log-ip-options Log IP options.\n\n" +" --log-uid Log UID owning the local socket.\n\n"); +} + +static const struct option LOG_opts[] = { + { .name = "log-level", .has_arg = 1, .val = '!' }, + { .name = "log-prefix", .has_arg = 1, .val = '#' }, + { .name = "log-tcp-sequence", .has_arg = 0, .val = '1' }, + { .name = "log-tcp-options", .has_arg = 0, .val = '2' }, + { .name = "log-ip-options", .has_arg = 0, .val = '3' }, + { .name = "log-uid", .has_arg = 0, .val = '4' }, + { .name = NULL } +}; + +static void LOG_init(struct xt_entry_target *t) +{ + struct ipt_log_info *loginfo = (struct ipt_log_info *)t->data; + + loginfo->level = LOG_DEFAULT_LEVEL; + +} + +struct ipt_log_names { + const char *name; + unsigned int level; +}; + +static const struct ipt_log_names ipt_log_names[] += { { .name = "alert", .level = LOG_ALERT }, + { .name = "crit", .level = LOG_CRIT }, + { .name = "debug", .level = LOG_DEBUG }, + { .name = "emerg", .level = LOG_EMERG }, + { .name = "error", .level = LOG_ERR }, /* DEPRECATED */ + { .name = "info", .level = LOG_INFO }, + { .name = "notice", .level = LOG_NOTICE }, + { .name = "panic", .level = LOG_EMERG }, /* DEPRECATED */ + { .name = "warning", .level = LOG_WARNING } +}; + +static u_int8_t +parse_level(const char *level) +{ + unsigned int lev = -1; + unsigned int set = 0; + + if (!xtables_strtoui(level, NULL, &lev, 0, 7)) { + unsigned int i = 0; + + for (i = 0; i < ARRAY_SIZE(ipt_log_names); ++i) + if (strncasecmp(level, ipt_log_names[i].name, + strlen(level)) == 0) { + if (set++) + xtables_error(PARAMETER_PROBLEM, + "log-level `%s' ambiguous", + level); + lev = ipt_log_names[i].level; + } + + if (!set) + xtables_error(PARAMETER_PROBLEM, + "log-level `%s' unknown", level); + } + + return lev; +} + +#define IPT_LOG_OPT_LEVEL 0x01 +#define IPT_LOG_OPT_PREFIX 0x02 +#define IPT_LOG_OPT_TCPSEQ 0x04 +#define IPT_LOG_OPT_TCPOPT 0x08 +#define IPT_LOG_OPT_IPOPT 0x10 +#define IPT_LOG_OPT_UID 0x20 + +static int LOG_parse(int c, char **argv, int invert, unsigned int *flags, + const void *entry, struct xt_entry_target **target) +{ + struct ipt_log_info *loginfo = (struct ipt_log_info *)(*target)->data; + + switch (c) { + case '!': + if (*flags & IPT_LOG_OPT_LEVEL) + xtables_error(PARAMETER_PROBLEM, + "Can't specify --log-level twice"); + + if (xtables_check_inverse(optarg, &invert, NULL, 0, argv)) + xtables_error(PARAMETER_PROBLEM, + "Unexpected `!' after --log-level"); + + loginfo->level = parse_level(optarg); + *flags |= IPT_LOG_OPT_LEVEL; + break; + + case '#': + if (*flags & IPT_LOG_OPT_PREFIX) + xtables_error(PARAMETER_PROBLEM, + "Can't specify --log-prefix twice"); + + if (xtables_check_inverse(optarg, &invert, NULL, 0, argv)) + xtables_error(PARAMETER_PROBLEM, + "Unexpected `!' after --log-prefix"); + + if (strlen(optarg) > sizeof(loginfo->prefix) - 1) + xtables_error(PARAMETER_PROBLEM, + "Maximum prefix length %u for --log-prefix", + (unsigned int)sizeof(loginfo->prefix) - 1); + + if (strlen(optarg) == 0) + xtables_error(PARAMETER_PROBLEM, + "No prefix specified for --log-prefix"); + + if (strlen(optarg) != strlen(strtok(optarg, "\n"))) + xtables_error(PARAMETER_PROBLEM, + "Newlines not allowed in --log-prefix"); + + strcpy(loginfo->prefix, optarg); + *flags |= IPT_LOG_OPT_PREFIX; + break; + + case '1': + if (*flags & IPT_LOG_OPT_TCPSEQ) + xtables_error(PARAMETER_PROBLEM, + "Can't specify --log-tcp-sequence " + "twice"); + + loginfo->logflags |= IPT_LOG_TCPSEQ; + *flags |= IPT_LOG_OPT_TCPSEQ; + break; + + case '2': + if (*flags & IPT_LOG_OPT_TCPOPT) + xtables_error(PARAMETER_PROBLEM, + "Can't specify --log-tcp-options twice"); + + loginfo->logflags |= IPT_LOG_TCPOPT; + *flags |= IPT_LOG_OPT_TCPOPT; + break; + + case '3': + if (*flags & IPT_LOG_OPT_IPOPT) + xtables_error(PARAMETER_PROBLEM, + "Can't specify --log-ip-options twice"); + + loginfo->logflags |= IPT_LOG_IPOPT; + *flags |= IPT_LOG_OPT_IPOPT; + break; + + case '4': + if (*flags & IPT_LOG_OPT_UID) + xtables_error(PARAMETER_PROBLEM, + "Can't specify --log-uid twice"); + + loginfo->logflags |= IPT_LOG_UID; + *flags |= IPT_LOG_OPT_UID; + break; + + default: + return 0; + } + + return 1; +} + +static void LOG_print(const void *ip, const struct xt_entry_target *target, + int numeric) +{ + const struct ipt_log_info *loginfo + = (const struct ipt_log_info *)target->data; + unsigned int i = 0; + + printf("LOG "); + if (numeric) + printf("flags %u level %u ", + loginfo->logflags, loginfo->level); + else { + for (i = 0; i < ARRAY_SIZE(ipt_log_names); ++i) + if (loginfo->level == ipt_log_names[i].level) { + printf("level %s ", ipt_log_names[i].name); + break; + } + if (i == ARRAY_SIZE(ipt_log_names)) + printf("UNKNOWN level %u ", loginfo->level); + if (loginfo->logflags & IPT_LOG_TCPSEQ) + printf("tcp-sequence "); + if (loginfo->logflags & IPT_LOG_TCPOPT) + printf("tcp-options "); + if (loginfo->logflags & IPT_LOG_IPOPT) + printf("ip-options "); + if (loginfo->logflags & IPT_LOG_UID) + printf("uid "); + if (loginfo->logflags & ~(IPT_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 ipt_log_info *loginfo + = (const struct ipt_log_info *)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 & IPT_LOG_TCPSEQ) + printf("--log-tcp-sequence "); + if (loginfo->logflags & IPT_LOG_TCPOPT) + printf("--log-tcp-options "); + if (loginfo->logflags & IPT_LOG_IPOPT) + printf("--log-ip-options "); + if (loginfo->logflags & IPT_LOG_UID) + printf("--log-uid "); +} + +static struct xtables_target log_tg_reg = { + .name = "LOG", + .version = XTABLES_VERSION, + .family = NFPROTO_IPV4, + .size = XT_ALIGN(sizeof(struct ipt_log_info)), + .userspacesize = XT_ALIGN(sizeof(struct ipt_log_info)), + .help = LOG_help, + .init = LOG_init, + .parse = LOG_parse, + .print = LOG_print, + .save = LOG_save, + .extra_opts = LOG_opts, +}; + +void _init(void) +{ + xtables_register_target(&log_tg_reg); +} |