[NETFILTER]: sip conntrack: minor cleanup

- Use enum for header field enumeration
- Use numerical value instead of pointer to header info structure to
  identify headers, unexport ct_sip_hdrs
- group SIP and SDP entries in header info structure
- remove double forward declaration of ct_sip_get_info

Signed-off-by: Patrick McHardy <kaber@trash.net>

3 files changed, 55 insertions, 63 deletions

diff --git a/include/linux/netfilter_ipv4/ip_conntrack_sip.h b/include/linux/netfilter_ipv4/ip_conntrack_sip.h
index 913dad66c0fb..2a15eb51fd6b 100644
--- a/include/linux/netfilter_ipv4/ip_conntrack_sip.h
+++ b/include/linux/netfilter_ipv4/ip_conntrack_sip.h
@@ -5,23 +5,15 @@
 #define SIP_PORT        5060
 #define SIP_TIMEOUT     3600
 
-#define POS_VIA         0
-#define POS_CONTACT     1
-#define POS_CONTENT     2
-#define POS_MEDIA       3
-#define POS_OWNER       4
-#define POS_CONNECTION  5
-#define POS_REQ_HEADER  6
-#define POS_SDP_HEADER  7
-
-struct sip_header_nfo {
-        const char      *lname;
-        const char      *sname;
-        const char      *ln_str;
-        size_t          lnlen;
-        size_t          snlen;
-        size_t          ln_strlen;
-        int             (*match_len)(const char *, const char *, int *);
+enum sip_header_pos {
+        POS_REQ_HEADER,
+        POS_VIA,
+        POS_CONTACT,
+        POS_CONTENT,
+        POS_MEDIA,
+        POS_OWNER,
+        POS_CONNECTION,
+        POS_SDP_HEADER,
 };
 
 extern unsigned int (*ip_nat_sip_hook)(struct sk_buff **pskb,
@@ -36,7 +28,7 @@ extern unsigned int (*ip_nat_sdp_hook)(struct sk_buff **pskb,
 extern int ct_sip_get_info(const char *dptr, size_t dlen,
                            unsigned int *matchoff,
                            unsigned int *matchlen,
-                           struct sip_header_nfo *hnfo);
+                           enum sip_header_pos pos);
 extern int ct_sip_lnlen(const char *line, const char *limit);
 extern const char *ct_sip_search(const char *needle, const char *haystack,
                                  size_t needle_len, size_t haystack_len);
diff --git a/net/ipv4/netfilter/ip_conntrack_sip.c b/net/ipv4/netfilter/ip_conntrack_sip.c
index bf423db4ed46..cc3176581667 100644
--- a/net/ipv4/netfilter/ip_conntrack_sip.c
+++ b/net/ipv4/netfilter/ip_conntrack_sip.c
@@ -52,20 +52,32 @@ unsigned int (*ip_nat_sdp_hook)(struct sk_buff **pskb,
                                 const char *dptr);
 EXPORT_SYMBOL_GPL(ip_nat_sdp_hook);
 
-int ct_sip_get_info(const char *dptr, size_t dlen,
-                                unsigned int *matchoff,
-                                unsigned int *matchlen,
-                                struct sip_header_nfo *hnfo);
-EXPORT_SYMBOL_GPL(ct_sip_get_info);
-
-
 static int digits_len(const char *dptr, const char *limit, int *shift);
 static int epaddr_len(const char *dptr, const char *limit, int *shift);
 static int skp_digits_len(const char *dptr, const char *limit, int *shift);
 static int skp_epaddr_len(const char *dptr, const char *limit, int *shift);
 
-struct sip_header_nfo ct_sip_hdrs[] = {
-        {       /* Via header */
+struct sip_header_nfo {
+        const char      *lname;
+        const char      *sname;
+        const char      *ln_str;
+        size_t          lnlen;
+        size_t          snlen;
+        size_t          ln_strlen;
+        int             (*match_len)(const char *, const char *, int *);
+};
+
+static struct sip_header_nfo ct_sip_hdrs[] = {
+        [POS_REQ_HEADER] = {    /* SIP Requests headers */
+                .lname          = "sip:",
+                .lnlen          = sizeof("sip:") - 1,
+                .sname          = "sip:",
+                .snlen          = sizeof("sip:") - 1, /* yes, i know.. ;) */
+                .ln_str         = "@",
+                .ln_strlen      = sizeof("@") - 1,
+                .match_len      = epaddr_len
+        },
+        [POS_VIA] = {           /* SIP Via header */
                 .lname          = "Via:",
                 .lnlen          = sizeof("Via:") - 1,
                 .sname          = "\r\nv:",
@@ -74,7 +86,7 @@ struct sip_header_nfo ct_sip_hdrs[] = {
                 .ln_strlen      = sizeof("UDP ") - 1,
                 .match_len      = epaddr_len,
         },
-        {       /* Contact header */
+        [POS_CONTACT] = {       /* SIP Contact header */
                 .lname          = "Contact:",
                 .lnlen          = sizeof("Contact:") - 1,
                 .sname          = "\r\nm:",
@@ -83,7 +95,7 @@ struct sip_header_nfo ct_sip_hdrs[] = {
                 .ln_strlen      = sizeof("sip:") - 1,
                 .match_len      = skp_epaddr_len
         },
-        {       /* Content length header */
+        [POS_CONTENT] = {       /* SIP Content length header */
                 .lname          = "Content-Length:",
                 .lnlen          = sizeof("Content-Length:") - 1,
                 .sname          = "\r\nl:",
@@ -92,7 +104,7 @@ struct sip_header_nfo ct_sip_hdrs[] = {
                 .ln_strlen      = sizeof(":") - 1,
                 .match_len      = skp_digits_len
         },
-        {       /* SDP media info */
+        [POS_MEDIA] = {         /* SDP media info */
                 .lname          = "\nm=",
                 .lnlen          = sizeof("\nm=") - 1,
                 .sname          = "\rm=",
@@ -101,7 +113,7 @@ struct sip_header_nfo ct_sip_hdrs[] = {
                 .ln_strlen      = sizeof("audio ") - 1,
                 .match_len      = digits_len
         },
-        {       /* SDP owner address*/
+        [POS_OWNER] = {         /* SDP owner address*/
                 .lname          = "\no=",
                 .lnlen          = sizeof("\no=") - 1,
                 .sname          = "\ro=",
@@ -110,7 +122,7 @@ struct sip_header_nfo ct_sip_hdrs[] = {
                 .ln_strlen      = sizeof("IN IP4 ") - 1,
                 .match_len      = epaddr_len
         },
-        {       /* SDP connection info */
+        [POS_CONNECTION] = {    /* SDP connection info */
                 .lname          = "\nc=",
                 .lnlen          = sizeof("\nc=") - 1,
                 .sname          = "\rc=",
@@ -119,16 +131,7 @@ struct sip_header_nfo ct_sip_hdrs[] = {
                 .ln_strlen      = sizeof("IN IP4 ") - 1,
                 .match_len      = epaddr_len
         },
-        {       /* Requests headers */
-                .lname          = "sip:",
-                .lnlen          = sizeof("sip:") - 1,
-                .sname          = "sip:",
-                .snlen          = sizeof("sip:") - 1, /* yes, i know.. ;) */
-                .ln_str         = "@",
-                .ln_strlen      = sizeof("@") - 1,
-                .match_len      = epaddr_len
-        },
-        {       /* SDP version header */
+        [POS_SDP_HEADER] = {    /* SDP version header */
                 .lname          = "\nv=",
                 .lnlen          = sizeof("\nv=") - 1,
                 .sname          = "\rv=",
@@ -138,7 +141,6 @@ struct sip_header_nfo ct_sip_hdrs[] = {
                 .match_len      = digits_len
         }
 };
-EXPORT_SYMBOL_GPL(ct_sip_hdrs);
 
 /* get line lenght until first CR or LF seen. */
 int ct_sip_lnlen(const char *line, const char *limit)
@@ -263,8 +265,9 @@ static int skp_epaddr_len(const char *dptr, const char *limit, int *shift)
 int ct_sip_get_info(const char *dptr, size_t dlen,
                     unsigned int *matchoff,
                     unsigned int *matchlen,
-                    struct sip_header_nfo *hnfo)
+                    enum sip_header_pos pos)
 {
+        struct sip_header_nfo *hnfo = &ct_sip_hdrs[pos];
         const char *limit, *aux, *k = dptr;
         int shift = 0;
 
@@ -298,6 +301,7 @@ int ct_sip_get_info(const char *dptr, size_t dlen,
         DEBUGP("%s header not found.\n", hnfo->lname);
         return 0;
 }
+EXPORT_SYMBOL_GPL(ct_sip_get_info);
 
 static int set_expected_rtp(struct sk_buff **pskb,
                             struct ip_conntrack *ct,
@@ -393,7 +397,7 @@ static int sip_help(struct sk_buff **pskb,
         }
         /* Get ip and port address from SDP packet. */
         if (ct_sip_get_info(dptr, datalen, &matchoff, &matchlen,
-                            &ct_sip_hdrs[POS_CONNECTION]) > 0) {
+                            POS_CONNECTION) > 0) {
 
                 /* We'll drop only if there are parse problems. */
                 if (parse_ipaddr(dptr + matchoff, NULL, &ipaddr,
@@ -402,7 +406,7 @@ static int sip_help(struct sk_buff **pskb,
                         goto out;
                 }
                 if (ct_sip_get_info(dptr, datalen, &matchoff, &matchlen,
-                                    &ct_sip_hdrs[POS_MEDIA]) > 0) {
+                                    POS_MEDIA) > 0) {
 
                         port = simple_strtoul(dptr + matchoff, NULL, 10);
                         if (port < 1024) {
diff --git a/net/ipv4/netfilter/ip_nat_sip.c b/net/ipv4/netfilter/ip_nat_sip.c
index 9fad98099532..47097aac63d8 100644
--- a/net/ipv4/netfilter/ip_nat_sip.c
+++ b/net/ipv4/netfilter/ip_nat_sip.c
@@ -29,18 +29,16 @@ MODULE_DESCRIPTION("SIP NAT helper");
 #define DEBUGP(format, args...)
 #endif
 
-extern struct sip_header_nfo ct_sip_hdrs[];
-
 static unsigned int mangle_sip_packet(struct sk_buff **pskb,
                                       enum ip_conntrack_info ctinfo,
                                       struct ip_conntrack *ct,
                                       const char **dptr, size_t dlen,
                                       char *buffer, int bufflen,
-                                      struct sip_header_nfo *hnfo)
+                                      enum sip_header_pos pos)
 {
         unsigned int matchlen, matchoff;
 
-        if (ct_sip_get_info(*dptr, dlen, &matchoff, &matchlen, hnfo) <= 0)
+        if (ct_sip_get_info(*dptr, dlen, &matchoff, &matchlen, pos) <= 0)
                 return 0;
 
         if (!ip_nat_mangle_udp_packet(pskb, ct, ctinfo,
@@ -80,14 +78,13 @@ static unsigned int ip_nat_sip(struct sk_buff **pskb,
                 if ((ctinfo) < IP_CT_IS_REPLY) {
                         mangle_sip_packet(pskb, ctinfo, ct, dptr,
                                           (*pskb)->len - dataoff,
-                                          buffer, bufflen,
-                                          &ct_sip_hdrs[POS_CONTACT]);
+                                          buffer, bufflen, POS_CONTACT);
                         return 1;
                 }
 
                 if (!mangle_sip_packet(pskb, ctinfo, ct, dptr,
                                        (*pskb)->len - dataoff,
-                                       buffer, bufflen, &ct_sip_hdrs[POS_VIA]))
+                                       buffer, bufflen, POS_VIA))
                         return 0;
 
                 /* This search should ignore case, but later.. */
@@ -102,25 +99,24 @@ static unsigned int ip_nat_sip(struct sk_buff **pskb,
 
                 return mangle_sip_packet(pskb, ctinfo, ct, dptr,
                                          (*pskb)->len - dataoff,
-                                         buffer, bufflen,
-                                         &ct_sip_hdrs[POS_CONTACT]);
+                                         buffer, bufflen, POS_CONTACT);
         }
         if ((ctinfo) < IP_CT_IS_REPLY) {
                 if (!mangle_sip_packet(pskb, ctinfo, ct, dptr,
                                        (*pskb)->len - dataoff,
-                                       buffer, bufflen, &ct_sip_hdrs[POS_VIA]))
+                                       buffer, bufflen, POS_VIA))
                         return 0;
 
                 /* Mangle Contact if exists only. - watch udp_nat_mangle()! */
                 mangle_sip_packet(pskb, ctinfo, ct, dptr, (*pskb)->len - dataoff,
-                                  buffer, bufflen, &ct_sip_hdrs[POS_CONTACT]);
+                                  buffer, bufflen, POS_CONTACT);
                 return 1;
         }
         /* This mangle requests headers. */
         return mangle_sip_packet(pskb, ctinfo, ct, dptr,
                                  ct_sip_lnlen(*dptr,
                                               *dptr + (*pskb)->len - dataoff),
-                                 buffer, bufflen, &ct_sip_hdrs[POS_REQ_HEADER]);
+                                 buffer, bufflen, POS_REQ_HEADER);
 }
 
 static int mangle_content_len(struct sk_buff **pskb,
@@ -136,7 +132,7 @@ static int mangle_content_len(struct sk_buff **pskb,
 
         /* Get actual SDP lenght */
         if (ct_sip_get_info(dptr, (*pskb)->len - dataoff, &matchoff,
-                            &matchlen, &ct_sip_hdrs[POS_SDP_HEADER]) > 0) {
+                            &matchlen, POS_SDP_HEADER) > 0) {
 
                 /* since ct_sip_get_info() give us a pointer passing 'v='
                    we need to add 2 bytes in this count. */
@@ -144,7 +140,7 @@ static int mangle_content_len(struct sk_buff **pskb,
 
                 /* Now, update SDP lenght */
                 if (ct_sip_get_info(dptr, (*pskb)->len - dataoff, &matchoff,
-                                    &matchlen, &ct_sip_hdrs[POS_CONTENT]) > 0) {
+                                    &matchlen, POS_CONTENT) > 0) {
 
                         bufflen = sprintf(buffer, "%u", c_len);
 
@@ -170,17 +166,17 @@ static unsigned int mangle_sdp(struct sk_buff **pskb,
         /* Mangle owner and contact info. */
         bufflen = sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(newip));
         if (!mangle_sip_packet(pskb, ctinfo, ct, &dptr, (*pskb)->len - dataoff,
-                               buffer, bufflen, &ct_sip_hdrs[POS_OWNER]))
+                               buffer, bufflen, POS_OWNER))
                 return 0;
 
         if (!mangle_sip_packet(pskb, ctinfo, ct, &dptr, (*pskb)->len - dataoff,
-                               buffer, bufflen, &ct_sip_hdrs[POS_CONNECTION]))
+                               buffer, bufflen, POS_CONNECTION))
                 return 0;
 
         /* Mangle media port. */
         bufflen = sprintf(buffer, "%u", port);
         if (!mangle_sip_packet(pskb, ctinfo, ct, &dptr, (*pskb)->len - dataoff,
-                               buffer, bufflen, &ct_sip_hdrs[POS_MEDIA]))
+                               buffer, bufflen, POS_MEDIA))
                 return 0;
 
         return mangle_content_len(pskb, ctinfo, ct, dptr);