diff options
Diffstat (limited to 'src/extra')
| -rw-r--r-- | src/extra/checksum.c | 5 | ||||
| -rw-r--r-- | src/extra/icmp.c | 57 | ||||
| -rw-r--r-- | src/extra/ipv4.c | 25 | ||||
| -rw-r--r-- | src/extra/ipv6.c | 41 | ||||
| -rw-r--r-- | src/extra/pktbuff.c | 160 | ||||
| -rw-r--r-- | src/extra/tcp.c | 27 | ||||
| -rw-r--r-- | src/extra/udp.c | 27 |
7 files changed, 282 insertions, 60 deletions
diff --git a/src/extra/checksum.c b/src/extra/checksum.c index a650b64..33480af 100644 --- a/src/extra/checksum.c +++ b/src/extra/checksum.c @@ -17,6 +17,7 @@ #include <netinet/ip6.h> #include <netinet/tcp.h> +#include <linux/netfilter/nfnetlink_queue.h> #include <libnetfilter_queue/libnetfilter_queue.h> #include "internal.h" @@ -80,7 +81,3 @@ uint16_t nfq_checksum_tcpudp_ipv6(struct ip6_hdr *ip6h, void *transport_hdr, return nfq_checksum(sum, (uint16_t *)payload, len); } - -/** - * @} - */ diff --git a/src/extra/icmp.c b/src/extra/icmp.c new file mode 100644 index 0000000..eaade7b --- /dev/null +++ b/src/extra/icmp.c @@ -0,0 +1,57 @@ +/* + * (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This code has been sponsored by Vyatta Inc. <http://www.vyatta.com> + */ + +#include <stdio.h> +#define _GNU_SOURCE +#include <netinet/ip_icmp.h> + +#include <libnetfilter_queue/libnetfilter_queue_icmp.h> + +#include "internal.h" + +/** + * \defgroup icmp ICMP helper functions + * + * \manonly +.SH SYNOPSIS +.nf +\fB +#include <libmnl/libmnl.h> +#include <libnetfilter_queue/libnetfilter_queue_icmp.h> +\endmanonly + * + * @{ + */ + +/** + * nfq_icmp_get_hdr - get the ICMP header. + * \param pktb: pointer to user-space network packet buffer + * \returns validated pointer to the ICMP header or NULL if the ICMP header was + * not set or if a minimal length check fails. + * \note You have to call nfq_ip_set_transport_header() or + * nfq_ip6_set_transport_header() first to set the ICMP header. + */ +EXPORT_SYMBOL +struct icmphdr *nfq_icmp_get_hdr(struct pkt_buff *pktb) +{ + if (pktb->transport_header == NULL) + return NULL; + + /* No room for the ICMP header. */ + if (pktb_tail(pktb) - pktb->transport_header < sizeof(struct icmphdr)) + return NULL; + + return (struct icmphdr *)pktb->transport_header; +} + +/** + * @} + */ diff --git a/src/extra/ipv4.c b/src/extra/ipv4.c index caafd37..58fb471 100644 --- a/src/extra/ipv4.c +++ b/src/extra/ipv4.c @@ -14,6 +14,7 @@ #include <arpa/inet.h> #include <netinet/ip.h> +#include <linux/netfilter/nfnetlink_queue.h> #include <libnetfilter_queue/libnetfilter_queue.h> #include <libnetfilter_queue/libnetfilter_queue_ipv4.h> #include <libnetfilter_queue/pktbuff.h> @@ -22,6 +23,15 @@ /** * \defgroup ipv4 IPv4 helper functions + * + * \manonly +.SH SYNOPSIS +.nf +\fB +#include <libmnl/libmnl.h> +#include <libnetfilter_queue/libnetfilter_queue_ipv4.h> +\endmanonly + * * @{ */ @@ -40,7 +50,7 @@ EXPORT_SYMBOL struct iphdr *nfq_ip_get_hdr(struct pkt_buff *pktb) { struct iphdr *iph; - unsigned int pktlen = pktb->tail - pktb->network_header; + unsigned int pktlen = pktb_tail(pktb) - pktb->network_header; /* Not enough room for IPv4 header. */ if (pktlen < sizeof(struct iphdr)) @@ -87,6 +97,15 @@ int nfq_ip_set_transport_header(struct pkt_buff *pktb, struct iphdr *iph) * * Most user-space programs will never need these. * + * + * \manonly +.SH SYNOPSIS +.nf +\fB +#include <libmnl/libmnl.h> +#include <libnetfilter_queue/libnetfilter_queue_ipv4.h> +\endmanonly + * * @{ */ @@ -135,14 +154,14 @@ int nfq_ip_mangle(struct pkt_buff *pktb, unsigned int dataoff, return 0; /* fix IP hdr checksum information */ - iph->tot_len = htons(pktb->tail - pktb->network_header); + iph->tot_len = htons(pktb_tail(pktb) - pktb->network_header); nfq_ip_set_checksum(iph); return 1; } /** - * nfq_pkt_snprintf_ip - print IPv4 header into buffer in iptables LOG format + * nfq_ip_snprintf - print IPv4 header into buffer in iptables LOG format * \param buf: Pointer to buffer that will be used to print the header * \param size: Size of the buffer (or remaining room in it) * \param iph: Pointer to a valid IPv4 header diff --git a/src/extra/ipv6.c b/src/extra/ipv6.c index 6e8820c..fd8ebc4 100644 --- a/src/extra/ipv6.c +++ b/src/extra/ipv6.c @@ -15,6 +15,7 @@ #include <arpa/inet.h> #include <netinet/ip6.h> +#include <linux/netfilter/nfnetlink_queue.h> #include <libnetfilter_queue/libnetfilter_queue.h> #include <libnetfilter_queue/libnetfilter_queue_ipv6.h> #include <libnetfilter_queue/pktbuff.h> @@ -23,6 +24,17 @@ /** * \defgroup ipv6 IPv6 helper functions + * + * \manonly +.SH SYNOPSIS +.nf +\fB +#include <arpa/inet.h> +#include <linux/netfilter/nfnetlink_queue.h> +#include <libnetfilter_queue/libnetfilter_queue.h> +#include <libnetfilter_queue/libnetfilter_queue_ipv6.h> +\endmanonly + * * @{ */ @@ -36,7 +48,7 @@ EXPORT_SYMBOL struct ip6_hdr *nfq_ip6_get_hdr(struct pkt_buff *pktb) { struct ip6_hdr *ip6h; - unsigned int pktlen = pktb->tail - pktb->network_header; + unsigned int pktlen = pktb_tail(pktb) - pktb->network_header; /* Not enough room for IPv6 header. */ if (pktlen < sizeof(struct ip6_hdr)) @@ -67,17 +79,26 @@ int nfq_ip6_set_transport_header(struct pkt_buff *pktb, struct ip6_hdr *ip6h, uint8_t nexthdr = ip6h->ip6_nxt; uint8_t *cur = (uint8_t *)ip6h + sizeof(struct ip6_hdr); - while (nexthdr != target) { + while (nexthdr == IPPROTO_HOPOPTS || + nexthdr == IPPROTO_ROUTING || + nexthdr == IPPROTO_FRAGMENT || + nexthdr == IPPROTO_AH || + nexthdr == IPPROTO_NONE || + nexthdr == IPPROTO_DSTOPTS) { struct ip6_ext *ip6_ext; uint32_t hdrlen; + /* Extension header was requested, we're done. */ + if (nexthdr == target) + break; + /* No more extensions, we're done. */ if (nexthdr == IPPROTO_NONE) { cur = NULL; break; } /* No room for extension, bad packet. */ - if (pktb->tail - cur < sizeof(struct ip6_ext)) { + if (pktb_tail(pktb) - cur < sizeof(struct ip6_ext)) { cur = NULL; break; } @@ -87,16 +108,16 @@ int nfq_ip6_set_transport_header(struct pkt_buff *pktb, struct ip6_hdr *ip6h, uint16_t *frag_off; /* No room for full fragment header, bad packet. */ - if (pktb->tail - cur < sizeof(struct ip6_frag)) { + if (pktb_tail(pktb) - cur < sizeof(struct ip6_frag)) { cur = NULL; break; } - frag_off = (uint16_t *)cur + - offsetof(struct ip6_frag, ip6f_offlg); + frag_off = (uint16_t *)(cur + + offsetof(struct ip6_frag, ip6f_offlg)); /* Fragment offset is only 13 bits long. */ - if (htons(*frag_off & ~0x7)) { + if (htons(*frag_off) & ~0x7) { /* Not the first fragment, it does not contain * any headers. */ @@ -107,11 +128,13 @@ int nfq_ip6_set_transport_header(struct pkt_buff *pktb, struct ip6_hdr *ip6h, } else if (nexthdr == IPPROTO_AH) hdrlen = (ip6_ext->ip6e_len + 2) << 2; else - hdrlen = ip6_ext->ip6e_len; + hdrlen = (ip6_ext->ip6e_len + 1) << 3; nexthdr = ip6_ext->ip6e_nxt; cur += hdrlen; } + if (nexthdr != target) + cur = NULL; pktb->transport_header = cur; return cur ? 1 : 0; } @@ -140,7 +163,7 @@ int nfq_ip6_mangle(struct pkt_buff *pktb, unsigned int dataoff, /* Fix IPv6 hdr length information */ ip6h->ip6_plen = - htons(pktb->tail - pktb->network_header - sizeof *ip6h); + htons(pktb_tail(pktb) - pktb->network_header - sizeof *ip6h); return 1; } diff --git a/src/extra/pktbuff.c b/src/extra/pktbuff.c index f013cfe..40d2250 100644 --- a/src/extra/pktbuff.c +++ b/src/extra/pktbuff.c @@ -23,12 +23,58 @@ /** * \defgroup pktbuff User-space network packet buffer * - * This library provides the user-space network packet buffer. This abstraction - * is strongly inspired by Linux kernel network buffer, the so-called sk_buff. + * These functions provide the user-space network packet buffer. + * This abstraction is strongly inspired by Linux kernel network buffer, + * the so-called sk_buff. + * + * \manonly +.SH SYNOPSIS +.nf +\fB +#include <libmnl/libmnl.h> +#include <libnetfilter_queue/pktbuff.h> +\endmanonly * * @{ */ +static int __pktb_setup(int family, struct pkt_buff *pktb) +{ + struct ethhdr *ethhdr; + + switch (family) { + case AF_INET: + case AF_INET6: + pktb->network_header = pktb->data; + break; + case AF_BRIDGE: + ethhdr = (struct ethhdr *)pktb->data; + pktb->mac_header = pktb->data; + + switch(ethhdr->h_proto) { + case ETH_P_IP: + case ETH_P_IPV6: + pktb->network_header = pktb->data + ETH_HLEN; + break; + default: + /* This protocol is unsupported. */ + errno = EPROTONOSUPPORT; + return -1; + } + break; + } + + return 0; +} + +static void pktb_setup_metadata(struct pkt_buff *pktb, void *pkt_data, + size_t len, size_t extra) +{ + pktb->len = len; + pktb->data_len = len + extra; + pktb->data = pkt_data; +} + /** * pktb_alloc - allocate a new packet buffer * \param family Indicate what family. Currently supported families are @@ -38,7 +84,12 @@ * \param extra Extra memory in the tail to be allocated (for mangling) * * This function returns a packet buffer that contains the packet data and - * some extra memory room in the tail (if requested). + * some extra memory room in the tail (if requested). This function copies + * the memory area provided as a pointer to packet data into the packet buffer + * structure. + * + * The extra length provides extra packet data room at the tail of the packet + * buffer in case you need to mangle it. * * \return Pointer to a new userspace packet buffer or NULL on failure. * \par Errors @@ -52,7 +103,6 @@ EXPORT_SYMBOL struct pkt_buff *pktb_alloc(int family, void *data, size_t len, size_t extra) { struct pkt_buff *pktb; - struct ethhdr *ethhdr; void *pkt_data; pktb = calloc(1, sizeof(struct pkt_buff) + len + extra); @@ -63,35 +113,44 @@ struct pkt_buff *pktb_alloc(int family, void *data, size_t len, size_t extra) pkt_data = (uint8_t *)pktb + sizeof(struct pkt_buff); memcpy(pkt_data, data, len); - pktb->len = len; - pktb->data_len = len + extra; + pktb_setup_metadata(pktb, pkt_data, len, extra); - pktb->head = pkt_data; - pktb->data = pkt_data; - pktb->tail = pktb->head + len; + if (__pktb_setup(family, pktb) < 0) { + free(pktb); + return NULL; + } - switch(family) { - case AF_INET: - case AF_INET6: - pktb->network_header = pktb->data; - break; - case AF_BRIDGE: - ethhdr = (struct ethhdr *)pktb->data; - pktb->mac_header = pktb->data; + return pktb; +} + +/** + * pktb_setup_raw - set up a packet buffer from memory area + * \param pktb Pointer to memory of length pktb_head_size() bytes + * \param family Supported families are AF_BRIDGE, AF_INET & AF_INET6. + * \param data Pointer to packet data + * \param len Packet data length + * \param extra Extra memory available after packet data (for mangling). + * + * Use this function to set up a packet buffer from a memory area, minimum size + * of such memory area must be pktb_head_size(). This function attaches the + * packet data that is provided to the packet buffer (data is not copied). Use + * this function as an alternative to the pktb_alloc() interface for more + * control on memory management. + * + * \return Pointer to a new userspace packet buffer or NULL on failure. + * \par Errors + * __EPROTONOSUPPORT__ _family_ was __AF_BRIDGE__ and this is not an IP packet + * (v4 or v6) + */ +EXPORT_SYMBOL +struct pkt_buff *pktb_setup_raw(void *pktb, int family, void *data, + size_t len, size_t extra) +{ + memset(pktb, 0, sizeof (struct pkt_buff)); + pktb_setup_metadata(pktb, data, len, extra); + if (__pktb_setup(family, pktb) < 0) + pktb = NULL; - switch(ethhdr->h_proto) { - case ETH_P_IP: - case ETH_P_IPV6: - pktb->network_header = pktb->data + ETH_HLEN; - break; - default: - /* This protocol is unsupported. */ - errno = EPROTONOSUPPORT; - free(pktb); - return NULL; - } - break; - } return pktb; } @@ -141,21 +200,37 @@ void pktb_free(struct pkt_buff *pktb) * \n * 1. Functions to get values of members of opaque __struct pktbuff__, described * below - * \n + * * 2. Internal functions, described in Module __Internal functions__ * + * \manonly +.SH SYNOPSIS +.nf +\fB +#include <libmnl/libmnl.h> +#include <libnetfilter_queue/pktbuff.h> +\endmanonly + * * @{ */ /** - * \defgroup uselessfns Internal functions + * \defgroup do_not_use Internal functions * - * \warning Do not use these functions. Instead, always use the mangle + * Do not use these functions. Instead, always use the mangle * function appropriate to the level at which you are working. * \n * pktb_mangle() uses all the below functions except _pktb_pull_, which is not * used by anything. * + * \manonly +.SH SYNOPSIS +.nf +\fB +#include <libmnl/libmnl.h> +#include <libnetfilter_queue/pktbuff.h> +\endmanonly + * * @{ */ @@ -191,7 +266,6 @@ void pktb_pull(struct pkt_buff *pktb, unsigned int len) EXPORT_SYMBOL void pktb_put(struct pkt_buff *pktb, unsigned int len) { - pktb->tail += len; pktb->len += len; } @@ -204,7 +278,6 @@ EXPORT_SYMBOL void pktb_trim(struct pkt_buff *pktb, unsigned int len) { pktb->len = len; - pktb->tail = pktb->head + len; } /** @@ -280,7 +353,6 @@ static int pktb_expand_tail(struct pkt_buff *pktb, int extra) return 0; pktb->len += extra; - pktb->tail = pktb->tail + extra; return 1; } @@ -311,7 +383,7 @@ static int enlarge_pkt(struct pkt_buff *pktb, unsigned int extra) * excess of \b rep_len over \b match_len \warning pktb_mangle does not update any checksums. Developers should use the appropriate mangler for the protocol level: nfq_ip_mangle(), - nfq_tcp_mangle_ipv4() or nfq_udp_mangle_ipv4(). IPv6 versions are planned. + nfq_tcp_mangle_ipv4(), nfq_udp_mangle_ipv4() or IPv6 variants. \n It is appropriate to use pktb_mangle to change the MAC header. */ @@ -335,7 +407,7 @@ int pktb_mangle(struct pkt_buff *pktb, /* move post-replacement */ memmove(data + match_offset + rep_len, data + match_offset + match_len, - pktb->tail - (pktb->network_header + dataoff + + pktb_tail(pktb) - (pktb->network_header + dataoff + match_offset + match_len)); /* insert data from buffer */ @@ -367,5 +439,17 @@ bool pktb_mangled(const struct pkt_buff *pktb) } /** + * pktb_head_size - get number of bytes needed for a packet buffer + * (control part only) + * \return size of struct pkt_buff + */ + +EXPORT_SYMBOL +size_t pktb_head_size(void) +{ + return sizeof(struct pkt_buff); +} + +/** * @} */ diff --git a/src/extra/tcp.c b/src/extra/tcp.c index cca20e7..720afd2 100644 --- a/src/extra/tcp.c +++ b/src/extra/tcp.c @@ -18,6 +18,7 @@ #define _GNU_SOURCE #include <netinet/tcp.h> +#include <linux/netfilter/nfnetlink_queue.h> #include <libnetfilter_queue/libnetfilter_queue.h> #include <libnetfilter_queue/libnetfilter_queue_tcp.h> #include <libnetfilter_queue/libnetfilter_queue_ipv4.h> @@ -28,6 +29,15 @@ /** * \defgroup tcp TCP helper functions + * + * \manonly +.SH SYNOPSIS +.nf +\fB +#include <libmnl/libmnl.h> +#include <libnetfilter_queue/libnetfilter_queue_tcp.h> +\endmanonly + * * @{ */ @@ -46,7 +56,7 @@ struct tcphdr *nfq_tcp_get_hdr(struct pkt_buff *pktb) return NULL; /* No room for the TCP header. */ - if (pktb->tail - pktb->transport_header < sizeof(struct tcphdr)) + if (pktb_tail(pktb) - pktb->transport_header < sizeof(struct tcphdr)) return NULL; return (struct tcphdr *)pktb->transport_header; @@ -68,7 +78,7 @@ void *nfq_tcp_get_payload(struct tcphdr *tcph, struct pkt_buff *pktb) return NULL; /* malformed TCP data offset. */ - if (pktb->transport_header + len > pktb->tail) + if (pktb->transport_header + len > pktb_tail(pktb)) return NULL; return pktb->transport_header + len; @@ -83,7 +93,7 @@ void *nfq_tcp_get_payload(struct tcphdr *tcph, struct pkt_buff *pktb) EXPORT_SYMBOL unsigned int nfq_tcp_get_payload_len(struct tcphdr *tcph, struct pkt_buff *pktb) { - return pktb->tail - pktb->transport_header - (tcph->doff * 4); + return pktb_tail(pktb) - pktb->transport_header - (tcph->doff * 4); } /** @@ -91,6 +101,17 @@ unsigned int nfq_tcp_get_payload_len(struct tcphdr *tcph, struct pkt_buff *pktb) * * Most user-space programs will never need these. * + * + * \manonly +.SH SYNOPSIS +.nf +\fB +#include <netinet/ip.h> +#include <netinet/ip6.h> +#include <netinet/tcp.h> +#include <libnetfilter_queue/libnetfilter_queue_tcp.h> +\endmanonly + * * @{ */ diff --git a/src/extra/udp.c b/src/extra/udp.c index dc476d4..ede2196 100644 --- a/src/extra/udp.c +++ b/src/extra/udp.c @@ -17,6 +17,7 @@ #define _GNU_SOURCE #include <netinet/udp.h> +#include <linux/netfilter/nfnetlink_queue.h> #include <libnetfilter_queue/libnetfilter_queue.h> #include <libnetfilter_queue/libnetfilter_queue_udp.h> #include <libnetfilter_queue/libnetfilter_queue_ipv4.h> @@ -27,6 +28,15 @@ /** * \defgroup udp UDP helper functions + * + * \manonly +.SH SYNOPSIS +.nf +\fB +#include <libmnl/libmnl.h> +#include <libnetfilter_queue/libnetfilter_queue_udp.h> +\endmanonly + * * @{ */ @@ -46,7 +56,7 @@ struct udphdr *nfq_udp_get_hdr(struct pkt_buff *pktb) return NULL; /* No room for the UDP header. */ - if (pktb->tail - pktb->transport_header < sizeof(struct udphdr)) + if (pktb_tail(pktb) - pktb->transport_header < sizeof(struct udphdr)) return NULL; return (struct udphdr *)pktb->transport_header; @@ -68,7 +78,7 @@ void *nfq_udp_get_payload(struct udphdr *udph, struct pkt_buff *pktb) return NULL; /* malformed UDP packet. */ - if (pktb->transport_header + len > pktb->tail) + if (pktb->transport_header + len > pktb_tail(pktb)) return NULL; return pktb->transport_header + sizeof(struct udphdr); @@ -83,7 +93,7 @@ void *nfq_udp_get_payload(struct udphdr *udph, struct pkt_buff *pktb) EXPORT_SYMBOL unsigned int nfq_udp_get_payload_len(struct udphdr *udph, struct pkt_buff *pktb) { - return pktb->tail - pktb->transport_header - sizeof(struct udphdr); + return pktb_tail(pktb) - pktb->transport_header - sizeof(struct udphdr); } /** @@ -91,6 +101,17 @@ unsigned int nfq_udp_get_payload_len(struct udphdr *udph, struct pkt_buff *pktb) * * Most user-space programs will never need these. * + * + * \manonly +.SH SYNOPSIS +.nf +\fB +#include <netinet/ip.h> +#include <netinet/ip6.h> +#include <netinet/udp.h> +#include <libnetfilter_queue/libnetfilter_queue_udp.h> +\endmanonly + * * @{ */ |