diff options
| -rw-r--r-- | net/netfilter/ipvs/Kconfig | 7 | ||||
| -rw-r--r-- | net/netfilter/ipvs/Makefile | 3 | ||||
| -rw-r--r-- | net/netfilter/ipvs/ip_vs_pe_sip.c | 167 |
3 files changed, 177 insertions, 0 deletions
diff --git a/net/netfilter/ipvs/Kconfig b/net/netfilter/ipvs/Kconfig index af3c9f48f2d..a22dac22705 100644 --- a/net/netfilter/ipvs/Kconfig +++ b/net/netfilter/ipvs/Kconfig @@ -256,4 +256,11 @@ config IP_VS_NFCT connection state to be exported to the Netfilter framework for filtering purposes. +config IP_VS_PE_SIP + tristate "SIP persistence engine" + depends on IP_VS_PROTO_UDP + depends on NF_CONNTRACK_SIP + ---help--- + Allow persistence based on the SIP Call-ID + endif # IP_VS diff --git a/net/netfilter/ipvs/Makefile b/net/netfilter/ipvs/Makefile index 4a87bf3c629..34ee602ddb6 100644 --- a/net/netfilter/ipvs/Makefile +++ b/net/netfilter/ipvs/Makefile @@ -35,3 +35,6 @@ obj-$(CONFIG_IP_VS_NQ) += ip_vs_nq.o # IPVS application helpers obj-$(CONFIG_IP_VS_FTP) += ip_vs_ftp.o + +# IPVS connection template retrievers +obj-$(CONFIG_IP_VS_PE_SIP) += ip_vs_pe_sip.o diff --git a/net/netfilter/ipvs/ip_vs_pe_sip.c b/net/netfilter/ipvs/ip_vs_pe_sip.c new file mode 100644 index 00000000000..a0539f13e2b --- /dev/null +++ b/net/netfilter/ipvs/ip_vs_pe_sip.c @@ -0,0 +1,167 @@ +#define KMSG_COMPONENT "IPVS" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include <linux/module.h> +#include <linux/kernel.h> + +#include <net/ip_vs.h> +#include <net/netfilter/nf_conntrack.h> +#include <linux/netfilter/nf_conntrack_sip.h> + +static const char *ip_vs_dbg_callid(char *buf, size_t buf_len, + const char *callid, size_t callid_len, + int *idx) +{ + size_t len = min(min(callid_len, (size_t)64), buf_len - *idx - 1); + memcpy(buf + *idx, callid, len); + buf[*idx+len] = '\0'; + *idx += len + 1; + return buf + *idx - len; +} + +#define IP_VS_DEBUG_CALLID(callid, len) \ + ip_vs_dbg_callid(ip_vs_dbg_buf, sizeof(ip_vs_dbg_buf), \ + callid, len, &ip_vs_dbg_idx) + +static int get_callid(const char *dptr, unsigned int dataoff, + unsigned int datalen, + unsigned int *matchoff, unsigned int *matchlen) +{ + /* Find callid */ + while (1) { + int ret = ct_sip_get_header(NULL, dptr, dataoff, datalen, + SIP_HDR_CALL_ID, matchoff, + matchlen); + if (ret > 0) + break; + if (!ret) + return 0; + dataoff += *matchoff; + } + + /* Empty callid is useless */ + if (!*matchlen) + return -EINVAL; + + /* Too large is useless */ + if (*matchlen > IP_VS_PEDATA_MAXLEN) + return -EINVAL; + + /* SIP headers are always followed by a line terminator */ + if (*matchoff + *matchlen == datalen) + return -EINVAL; + + /* RFC 2543 allows lines to be terminated with CR, LF or CRLF, + * RFC 3261 allows only CRLF, we support both. */ + if (*(dptr + *matchoff + *matchlen) != '\r' && + *(dptr + *matchoff + *matchlen) != '\n') + return -EINVAL; + + IP_VS_DBG_BUF(9, "SIP callid %s (%d bytes)\n", + IP_VS_DEBUG_CALLID(dptr + *matchoff, *matchlen), + *matchlen); + return 0; +} + +static int +ip_vs_sip_fill_param(struct ip_vs_conn_param *p, struct sk_buff *skb) +{ + struct ip_vs_iphdr iph; + unsigned int dataoff, datalen, matchoff, matchlen; + const char *dptr; + + ip_vs_fill_iphdr(p->af, skb_network_header(skb), &iph); + + /* Only useful with UDP */ + if (iph.protocol != IPPROTO_UDP) + return -EINVAL; + + /* No Data ? */ + dataoff = iph.len + sizeof(struct udphdr); + if (dataoff >= skb->len) + return -EINVAL; + + dptr = skb->data + dataoff; + datalen = skb->len - dataoff; + + if (get_callid(dptr, dataoff, datalen, &matchoff, &matchlen)) + return -EINVAL; + + p->pe_data = kmalloc(matchlen, GFP_ATOMIC); + if (!p->pe_data) + return -ENOMEM; + + /* N.B: pe_data is only set on success, + * this allows fallback to the default persistence logic on failure + */ + memcpy(p->pe_data, dptr + matchoff, matchlen); + p->pe_data_len = matchlen; + + return 0; +} + +static bool ip_vs_sip_ct_match(const struct ip_vs_conn_param *p, + struct ip_vs_conn *ct) + +{ + bool ret = 0; + + if (ct->af == p->af && + ip_vs_addr_equal(p->af, p->caddr, &ct->caddr) && + /* protocol should only be IPPROTO_IP if + * d_addr is a fwmark */ + ip_vs_addr_equal(p->protocol == IPPROTO_IP ? AF_UNSPEC : p->af, + p->vaddr, &ct->vaddr) && + ct->vport == p->vport && + ct->flags & IP_VS_CONN_F_TEMPLATE && + ct->protocol == p->protocol && + ct->pe_data && ct->pe_data_len == p->pe_data_len && + !memcmp(ct->pe_data, p->pe_data, p->pe_data_len)) + ret = 1; + + IP_VS_DBG_BUF(9, "SIP template match %s %s->%s:%d %s\n", + ip_vs_proto_name(p->protocol), + IP_VS_DEBUG_CALLID(p->pe_data, p->pe_data_len), + IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport), + ret ? "hit" : "not hit"); + + return ret; +} + +static u32 ip_vs_sip_hashkey_raw(const struct ip_vs_conn_param *p, + u32 initval, bool inverse) +{ + return jhash(p->pe_data, p->pe_data_len, initval); +} + +static int ip_vs_sip_show_pe_data(const struct ip_vs_conn *cp, char *buf) +{ + memcpy(buf, cp->pe_data, cp->pe_data_len); + return cp->pe_data_len; +} + +static struct ip_vs_pe ip_vs_sip_pe = +{ + .name = "sip", + .refcnt = ATOMIC_INIT(0), + .module = THIS_MODULE, + .n_list = LIST_HEAD_INIT(ip_vs_sip_pe.n_list), + .fill_param = ip_vs_sip_fill_param, + .ct_match = ip_vs_sip_ct_match, + .hashkey_raw = ip_vs_sip_hashkey_raw, + .show_pe_data = ip_vs_sip_show_pe_data, +}; + +static int __init ip_vs_sip_init(void) +{ + return register_ip_vs_pe(&ip_vs_sip_pe); +} + +static void __exit ip_vs_sip_cleanup(void) +{ + unregister_ip_vs_pe(&ip_vs_sip_pe); +} + +module_init(ip_vs_sip_init); +module_exit(ip_vs_sip_cleanup); +MODULE_LICENSE("GPL"); |