Simplify control messages printers

Do not pass sizeof(struct cmsghdr) to every cmsg printer.

* net.c (printcmsghdr): Pass pointer to cmsg_data and length
of cmsg_data to print_cmsg_type_data.
(print_cmsg_type_data): Update prototype.  Pass pointer to cmsg_data
and length of cmsg_data to cmsg printers.
(print_scm_rights, print_scm_creds, print_scm_security): Update.

diff --git a/net.c b/net.c
index 188044812cb159a9429807e6be8fd798c7599ce0..3dd1368f61ec55432d55094154c9455ad145b92b 100644 (file)
--- a/net.c
+++ b/net.c
@@ -320,17 +320,18 @@ typedef union {
 } union_cmsghdr;
 
 static void
-print_scm_rights(struct tcb *tcp, const size_t cmsg_size, const char *ptr,
-                const size_t cmsg_len)
+print_scm_rights(struct tcb *tcp, const void *cmsg_data,
+                const size_t data_len)
 {
-       if (cmsg_size + sizeof(int) > cmsg_len)
-               return;
-
-       const int *fds = (const int *) (ptr + cmsg_size);
+       const int *fds = cmsg_data;
+       const char *end = (const char *) cmsg_data + data_len;
        bool seen = false;
 
+       if (sizeof(*fds) > data_len)
+               return;
+
        tprints(", [");
-       while ((const char *) fds < (ptr + cmsg_len)) {
+       while ((const char *) fds < end) {
                if (seen)
                        tprints(", ");
                else
@@ -341,48 +342,45 @@ print_scm_rights(struct tcb *tcp, const size_t cmsg_size, const char *ptr,
 }
 
 static void
-print_scm_creds(struct tcb *tcp, const size_t cmsg_size, const char *ptr,
-               const size_t cmsg_len)
+print_scm_creds(struct tcb *tcp, const void *cmsg_data,
+               const size_t data_len)
 {
-       if (cmsg_size + sizeof(struct ucred) > cmsg_len)
-               return;
+       const struct ucred *uc = cmsg_data;
 
-       const struct ucred *uc = (const void *) (ptr + cmsg_size);
+       if (sizeof(*uc) > data_len)
+               return;
 
        tprintf(", {pid=%u, uid=%u, gid=%u}",
                (unsigned) uc->pid, (unsigned) uc->uid, (unsigned) uc->gid);
 }
 
 static void
-print_scm_security(struct tcb *tcp, const size_t cmsg_size, const char *ptr,
-                  const size_t cmsg_len)
+print_scm_security(struct tcb *tcp, const void *cmsg_data,
+                  const size_t data_len)
 {
-       if (cmsg_size + sizeof(char) > cmsg_len)
+       if (!data_len)
                return;
 
-       const char *label = ptr + cmsg_size;
-       const size_t label_len = cmsg_len - cmsg_size;
-
        tprints(", ");
-       print_quoted_string(label, label_len, 0);
+       print_quoted_string(cmsg_data, data_len, 0);
 }
 
 static void
 print_cmsg_type_data(struct tcb *tcp, const int cmsg_level, const int cmsg_type,
-                    const size_t cmsg_size, const char *ptr, const size_t cmsg_len)
+                    const void *cmsg_data, const size_t data_len)
 {
        switch (cmsg_level) {
        case SOL_SOCKET:
                printxval(scmvals, cmsg_type, "SCM_???");
                switch (cmsg_type) {
                case SCM_RIGHTS:
-                       print_scm_rights(tcp, cmsg_size, ptr, cmsg_len);
+                       print_scm_rights(tcp, cmsg_data, data_len);
                        break;
                case SCM_CREDENTIALS:
-                       print_scm_creds(tcp, cmsg_size, ptr, cmsg_len);
+                       print_scm_creds(tcp, cmsg_data, data_len);
                        break;
                case SCM_SECURITY:
-                       print_scm_security(tcp, cmsg_size, ptr, cmsg_len);
+                       print_scm_security(tcp, cmsg_data, data_len);
                        break;
                }
                break;
@@ -438,7 +436,8 @@ printcmsghdr(struct tcb *tcp, unsigned long addr, size_t len)
                        cmsg_len = len;
 
                print_cmsg_type_data(tcp, cmsg_level, cmsg_type,
-                                    cmsg_size, u.ptr, cmsg_len);
+                                    (const void *) (u.ptr + cmsg_size),
+                                    cmsg_len > cmsg_size ? cmsg_len - cmsg_size: 0);
                tprints("}");
 
                if (cmsg_len < cmsg_size) {