patch-2.3.99-pre2 linux/net/ipv4/netfilter/ipt_LOG.c

• Lines: 369
• Date: Sat Mar 18 16:51:35 2000
• Orig file: v2.3.99-pre1/linux/net/ipv4/netfilter/ipt_LOG.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.99-pre1/linux/net/ipv4/netfilter/ipt_LOG.c linux/net/ipv4/netfilter/ipt_LOG.c
@@ -0,0 +1,368 @@
+/*
+ * This is a module which is used for logging packets.
+ */
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <linux/spinlock.h>
+#include <net/icmp.h>
+#include <net/udp.h>
+#include <net/tcp.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+
+struct in_device;
+#include <net/route.h>
+#include <linux/netfilter_ipv4/ipt_LOG.h>
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(format, args...)
+#endif
+
+struct esphdr {
+	__u32   spi;
+}; /* FIXME evil kludge */
+        
+/* Make init and cleanup non-static, so gcc doesn't warn about unused,
+   but don't export the symbols */
+EXPORT_NO_SYMBOLS;
+
+/* Use lock to serialize, so printks don't overlap */
+static spinlock_t log_lock = SPIN_LOCK_UNLOCKED;
+
+/* One level of recursion won't kill us */
+static void dump_packet(const struct ipt_log_info *info,
+			struct iphdr *iph, unsigned int len, int recurse)
+{
+	void *protoh = (u_int32_t *)iph + iph->ihl;
+	unsigned int datalen = len - iph->ihl * 4;
+
+	/* Important fields:
+	 * TOS, len, DF/MF, fragment offset, TTL, src, dst, options. */
+	/* Max length: 40 "SRC=255.255.255.255 DST=255.255.255.255 " */
+	printk("SRC=%u.%u.%u.%u DST=%u.%u.%u.%u ",
+	       (ntohl(iph->saddr)>>24)&0xFF,
+	       (ntohl(iph->saddr)>>16)&0xFF,
+	       (ntohl(iph->saddr)>>8)&0xFF,
+	       (ntohl(iph->saddr))&0xFF,
+	       (ntohl(iph->daddr)>>24)&0xFF,
+	       (ntohl(iph->daddr)>>16)&0xFF,
+	       (ntohl(iph->daddr)>>8)&0xFF,
+	       (ntohl(iph->daddr))&0xFF);
+
+	/* Max length: 46 "LEN=65535 TOS=0xFF PREC=0xFF TTL=255 ID=65535 " */
+	printk("LEN=%u TOS=0x%02X PREC=0x%02X TTL=%u ID=%u ",
+	       ntohs(iph->tot_len), iph->tos & IPTOS_TOS_MASK,
+	       iph->tos & IPTOS_PREC_MASK, iph->ttl, ntohs(iph->id));
+
+	/* Max length: 6 "CE DF MF " */
+	if (ntohs(iph->frag_off) & IP_CE)
+		printk("CE ");
+	if (ntohs(iph->frag_off) & IP_DF)
+		printk("DF ");
+	if (ntohs(iph->frag_off) & IP_MF)
+		printk("MF ");
+
+	/* Max length: 11 "FRAG:65535 " */
+	if (ntohs(iph->frag_off) & IP_OFFSET)
+		printk("FRAG:%u ", ntohs(iph->frag_off) & IP_OFFSET);
+
+	if ((info->logflags & IPT_LOG_IPOPT)
+	    && iph->ihl * 4 != sizeof(struct iphdr)) {
+		unsigned int i;
+
+		/* Max length: 127 "OPT (" 15*4*2chars ") " */
+		printk("OPT (");
+		for (i = sizeof(struct iphdr); i < iph->ihl * 4; i++)
+			printk("%02X", ((u_int8_t *)iph)[i]);
+		printk(") ");
+	}
+
+	switch (iph->protocol) {
+	case IPPROTO_TCP: {
+		struct tcphdr *tcph = protoh;
+
+		/* Max length: 10 "PROTO=TCP " */
+		printk("PROTO=TCP ");
+
+		if (ntohs(iph->frag_off) & IP_OFFSET)
+			break;
+
+		/* Max length: 25 "INCOMPLETE [65535 bytes] " */
+		if (datalen < sizeof (*tcph)) {
+			printk("INCOMPLETE [%u bytes] ", datalen);
+			break;
+		}
+
+		/* Max length: 20 "SPT=65535 DPT=65535 " */
+		printk("SPT=%u DPT=%u ",
+		       ntohs(tcph->source), ntohs(tcph->dest));
+		/* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */
+		if (info->logflags & IPT_LOG_TCPSEQ)
+			printk("SEQ=%u ACK=%u ",
+			       ntohl(tcph->seq), ntohl(tcph->ack_seq));
+		/* Max length: 13 "WINDOW=65535 " */
+		printk("WINDOW=%u ", ntohs(tcph->window));
+		/* Max length: 9 "RES=0x3F " */
+		printk("RES=0x%02x ", (u_int8_t)(ntohl(tcp_flag_word(tcph) & TCP_RESERVED_BITS) >> 22));
+		/* Max length: 36 "URG ACK PSH RST SYN FIN " */
+		if (tcph->urg)
+			printk("URG ");
+		if (tcph->ack)
+			printk("ACK ");
+		if (tcph->psh)
+			printk("PSH ");
+		if (tcph->rst)
+			printk("RST ");
+		if (tcph->syn)
+			printk("SYN ");
+		if (tcph->fin)
+			printk("FIN ");
+		/* Max length: 11 "URGP=65535 " */
+		printk("URGP=%u ", ntohs(tcph->urg_ptr));
+
+		if ((info->logflags & IPT_LOG_TCPOPT)
+		    && tcph->doff * 4 != sizeof(struct tcphdr)) {
+			unsigned int i;
+
+			/* Max length: 127 "OPT (" 15*4*2chars ") " */
+			printk("OPT (");
+			for (i =sizeof(struct tcphdr); i < tcph->doff * 4; i++)
+				printk("%02X", ((u_int8_t *)tcph)[i]);
+			printk(") ");
+		}
+		break;
+	}
+	case IPPROTO_UDP: {
+		struct udphdr *udph = protoh;
+
+		/* Max length: 10 "PROTO=UDP " */
+		printk("PROTO=UDP ");
+
+		if (ntohs(iph->frag_off) & IP_OFFSET)
+			break;
+
+		/* Max length: 25 "INCOMPLETE [65535 bytes] " */
+		if (datalen < sizeof (*udph)) {
+			printk("INCOMPLETE [%u bytes] ", datalen);
+			break;
+		}
+
+		/* Max length: 20 "SPT=65535 DPT=65535 " */
+		printk("SPT=%u DPT=%u LEN=%u ",
+		       ntohs(udph->source), ntohs(udph->dest),
+		       ntohs(udph->len));
+		break;
+	}
+	case IPPROTO_ICMP: {
+		struct icmphdr *icmph = protoh;
+		static size_t required_len[NR_ICMP_TYPES+1]
+			= { [ICMP_ECHOREPLY] = 4,
+			    [ICMP_DEST_UNREACH]
+			    = 8 + sizeof(struct iphdr) + 8,
+			    [ICMP_SOURCE_QUENCH]
+			    = 8 + sizeof(struct iphdr) + 8,
+			    [ICMP_REDIRECT]
+			    = 8 + sizeof(struct iphdr) + 8,
+			    [ICMP_ECHO] = 4,
+			    [ICMP_TIME_EXCEEDED]
+			    = 8 + sizeof(struct iphdr) + 8,
+			    [ICMP_PARAMETERPROB]
+			    = 8 + sizeof(struct iphdr) + 8,
+			    [ICMP_TIMESTAMP] = 20,
+			    [ICMP_TIMESTAMPREPLY] = 20,
+			    [ICMP_ADDRESS] = 12,
+			    [ICMP_ADDRESSREPLY] = 12 };
+
+		/* Max length: 11 "PROTO=ICMP " */
+		printk("PROTO=ICMP ");
+
+		if (ntohs(iph->frag_off) & IP_OFFSET)
+			break;
+
+		/* Max length: 25 "INCOMPLETE [65535 bytes] " */
+		if (datalen < 4) {
+			printk("INCOMPLETE [%u bytes] ", datalen);
+			break;
+		}
+
+		/* Max length: 18 "TYPE=255 CODE=255 " */
+		printk("TYPE=%u CODE=%u ", icmph->type, icmph->code);
+
+		/* Max length: 25 "INCOMPLETE [65535 bytes] " */
+		if (icmph->type <= NR_ICMP_TYPES
+		    && required_len[icmph->type]
+		    && datalen < required_len[icmph->type]) {
+			printk("INCOMPLETE [%u bytes] ", datalen);
+			break;
+		}
+
+		switch (icmph->type) {
+		case ICMP_ECHOREPLY:
+		case ICMP_ECHO:
+			/* Max length: 19 "ID=65535 SEQ=65535 " */
+			printk("ID=%u SEQ=%u ",
+			       ntohs(icmph->un.echo.id),
+			       ntohs(icmph->un.echo.sequence));
+			break;
+
+		case ICMP_PARAMETERPROB:
+			/* Max length: 14 "PARAMETER=255 " */
+			printk("PARAMETER=%u ",
+			       ntohl(icmph->un.gateway) >> 24);
+			break;
+		case ICMP_REDIRECT:
+			/* Max length: 24 "GATEWAY=255.255.255.255 " */
+			printk("GATEWAY=%u.%u.%u.%u ",
+			       (ntohl(icmph->un.gateway)>>24)&0xFF,
+			       (ntohl(icmph->un.gateway)>>16)&0xFF,
+			       (ntohl(icmph->un.gateway)>>8)&0xFF,
+			       (ntohl(icmph->un.gateway))&0xFF);
+			/* Fall through */
+		case ICMP_DEST_UNREACH:
+		case ICMP_SOURCE_QUENCH:
+		case ICMP_TIME_EXCEEDED:
+			/* Max length: 3+maxlen */
+			if (recurse) {
+				printk("[");
+				dump_packet(info,
+					    (struct iphdr *)(icmph + 1),
+					    datalen-sizeof(struct iphdr),
+					    0);
+				printk("] ");
+			}
+
+			/* Max length: 10 "MTU=65535 " */
+			if (icmph->type == ICMP_DEST_UNREACH
+			    && icmph->code == ICMP_FRAG_NEEDED)
+				printk("MTU=%u ", ntohs(icmph->un.frag.mtu));
+		}
+		break;
+	}
+	/* Max Length */
+	case IPPROTO_AH:
+	case IPPROTO_ESP: {
+		struct esphdr *esph = protoh;
+		int esp= (iph->protocol==IPPROTO_ESP);
+
+		/* Max length: 10 "PROTO=ESP " */
+		printk("PROTO=%s ",esp? "ESP" : "AH");
+
+		if (ntohs(iph->frag_off) & IP_OFFSET)
+			break;
+
+		/* Max length: 25 "INCOMPLETE [65535 bytes] " */
+		if (datalen < sizeof (*esph)) {
+			printk("INCOMPLETE [%u bytes] ", datalen);
+			break;
+		}
+
+		/* Length: 15 "SPI=0xF1234567 " */
+		printk("SPI=0x%x ", ntohl(esph->spi) );
+		break;
+	}
+	/* Max length: 10 "PROTO 255 " */
+	default:
+		printk("PROTO=%u ", iph->protocol);
+	}
+
+	/* Proto    Max log string length */
+	/* IP:      40+46+6+11+127 = 230 */
+	/* TCP:     10+max(25,20+30+13+9+36+11+127) = 256 */
+	/* UDP:     10+max(25,20) = 35 */
+	/* ICMP:    11+max(25, 18+25+max(19,14,24+3+n+10,3+n+10)) = 91+n */
+	/* ESP:     10+max(25)+15 = 50 */
+	/* AH:      9+max(25)+15 = 49 */
+	/* unknown: 10 */
+
+	/* (ICMP allows recursion one level deep) */
+	/* maxlen =  IP + ICMP +  IP + max(TCP,UDP,ICMP,unknown) */
+	/* maxlen = 230+   91  + 230 + 256 = 807 */
+}
+
+static unsigned int
+ipt_log_target(struct sk_buff **pskb,
+	       unsigned int hooknum,
+	       const struct net_device *in,
+	       const struct net_device *out,
+	       const void *targinfo,
+	       void *userinfo)
+{
+	struct iphdr *iph = (*pskb)->nh.iph;
+	const struct ipt_log_info *loginfo = targinfo;
+	char level_string[4] = "< >";
+
+	level_string[1] = '0' + (loginfo->level % 8);
+	spin_lock_bh(&log_lock);
+	printk(level_string);
+	printk("%sIN=%s OUT=%s ",
+	       loginfo->prefix,
+	       in ? in->name : "",
+	       out ? out->name : "");
+	if (in && !out) {
+		/* MAC logging for input chain only. */
+		printk("MAC=");
+		if ((*pskb)->dev && (*pskb)->dev->hard_header_len) {
+			int i;
+			unsigned char *p = (*pskb)->mac.raw;
+			for (i = 0; i < (*pskb)->dev->hard_header_len; i++,p++)
+				printk("%02x%c", *p,
+				       i==(*pskb)->dev->hard_header_len - 1
+				       ? ' ':':');
+		}
+	}
+
+	dump_packet(loginfo, iph, (*pskb)->len, 1);
+	printk("\n");
+	spin_unlock_bh(&log_lock);
+
+	return IPT_CONTINUE;
+}
+
+static int ipt_log_checkentry(const char *tablename,
+			      const struct ipt_entry *e,
+			      void *targinfo,
+			      unsigned int targinfosize,
+			      unsigned int hook_mask)
+{
+	const struct ipt_log_info *loginfo = targinfo;
+
+	if (targinfosize != IPT_ALIGN(sizeof(struct ipt_log_info))) {
+		DEBUGP("LOG: targinfosize %u != %u\n",
+		       targinfosize, IPT_ALIGN(sizeof(struct ipt_log_info)));
+		return 0;
+	}
+
+	if (loginfo->level >= 8) {
+		DEBUGP("LOG: level %u >= 8\n", loginfo->level);
+		return 0;
+	}
+
+	if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') {
+		DEBUGP("LOG: prefix term %i\n",
+		       loginfo->prefix[sizeof(loginfo->prefix)-1]);
+		return 0;
+	}
+
+	return 1;
+}
+
+static struct ipt_target ipt_log_reg
+= { { NULL, NULL }, "LOG", ipt_log_target, ipt_log_checkentry, THIS_MODULE };
+
+static int __init init(void)
+{
+    if (ipt_register_target(&ipt_log_reg))
+	return -EINVAL;
+
+    return 0;
+}
+
+static void __exit fini(void)
+{
+    ipt_unregister_target(&ipt_log_reg);
+}
+
+module_init(init);
+module_exit(fini);