msghdr.c: reorganize struct cmsghdr handler

* msghdr.c (sock_ee): New structure.
(print_scm_rights, print_scm_creds, print_scm_security,
print_cmsg_ip_pktinfo, print_cmsg_uint, print_cmsg_ip_opts,
print_cmsg_ip_recverr, print_cmsg_ip_origdstaddr): Remove data_len
argument validity check, don't print ", cmsg_data=" prefix here.
(print_cmsg_ip_tos): Likewise.  Rename to print_cmsg_uint8_t.
(cmsg_printer): New type.
(cmsg_socket_printers, cmsg_ip_printers): New arrays.
(print_cmsg_type_data): Use them to handle struct cmsghdr
and its cmsg_data.

diff --git a/msghdr.c b/msghdr.c
index ca61da1cf301675379df51379b26c9a4437c95b9..c4d8aef38ce7311d719dab54ce95a79a0ad3b190 100644 (file)
--- a/msghdr.c
+++ b/msghdr.c
@@ -61,10 +61,7 @@ print_scm_rights(struct tcb *tcp, const void *cmsg_data, const size_t data_len)
        const size_t nfds = data_len / sizeof(*fds);
        size_t i;
 
-       if (!nfds)
-               return;
-
-       tprints(", cmsg_data=[");
+       tprints("[");
 
        for (i = 0; i < nfds; ++i) {
                if (i)
@@ -80,10 +77,7 @@ print_scm_creds(struct tcb *tcp, const void *cmsg_data, const size_t data_len)
 {
        const struct ucred *uc = cmsg_data;
 
-       if (sizeof(*uc) > data_len)
-               return;
-
-       tprintf(", cmsg_data={pid=%u, uid=%u, gid=%u}",
+       tprintf("{pid=%u, uid=%u, gid=%u}",
                (unsigned) uc->pid, (unsigned) uc->uid, (unsigned) uc->gid);
 }
 
@@ -91,10 +85,6 @@ static void
 print_scm_security(struct tcb *tcp, const void *cmsg_data,
                   const size_t data_len)
 {
-       if (!data_len)
-               return;
-
-       tprints(", cmsg_data=");
        print_quoted_string(cmsg_data, data_len, 0);
 }
 
@@ -104,10 +94,7 @@ print_cmsg_ip_pktinfo(struct tcb *tcp, const void *cmsg_data,
 {
        const struct in_pktinfo *info = cmsg_data;
 
-       if (sizeof(*info) > data_len)
-               return;
-
-       tprints(", cmsg_data={ipi_ifindex=");
+       tprints("{ipi_ifindex=");
        print_ifindex(info->ipi_ifindex);
        tprintf(", ipi_spec_dst=inet_addr(\"%s\")",
                inet_ntoa(info->ipi_spec_dst));
@@ -120,22 +107,16 @@ print_cmsg_uint(struct tcb *tcp, const void *cmsg_data, const size_t data_len)
 {
        const unsigned int *p = cmsg_data;
 
-       if (sizeof(*p) > data_len)
-               return;
-
-       tprintf(", cmsg_data=[%u]", *p);
+       tprintf("[%u]", *p);
 }
 
 static void
-print_cmsg_ip_tos(struct tcb *tcp, const void *cmsg_data,
-                 const size_t data_len)
+print_cmsg_uint8_t(struct tcb *tcp, const void *cmsg_data,
+                  const size_t data_len)
 {
-       const uint8_t *tos = cmsg_data;
-
-       if (sizeof(*tos) > data_len)
-               return;
+       const uint8_t *p = cmsg_data;
 
-       tprintf(", cmsg_data=[%#x]", *tos);
+       tprintf("[%#x]", *p);
 }
 
 static void
@@ -145,10 +126,7 @@ print_cmsg_ip_opts(struct tcb *tcp, const void *cmsg_data,
        const unsigned char *opts = cmsg_data;
        size_t i;
 
-       if (!data_len)
-               return;
-
-       tprints(", cmsg_data=[");
+       tprints("[");
        for (i = 0; i < data_len; ++i) {
                if (i)
                        tprints(", ");
@@ -157,25 +135,24 @@ print_cmsg_ip_opts(struct tcb *tcp, const void *cmsg_data,
        tprints("]");
 }
 
+struct sock_ee {
+       uint32_t ee_errno;
+       uint8_t  ee_origin;
+       uint8_t  ee_type;
+       uint8_t  ee_code;
+       uint8_t  ee_pad;
+       uint32_t ee_info;
+       uint32_t ee_data;
+       struct sockaddr_in offender;
+};
+
 static void
 print_cmsg_ip_recverr(struct tcb *tcp, const void *cmsg_data,
                      const size_t data_len)
 {
-       const struct {
-               uint32_t ee_errno;
-               uint8_t  ee_origin;
-               uint8_t  ee_type;
-               uint8_t  ee_code;
-               uint8_t  ee_pad;
-               uint32_t ee_info;
-               uint32_t ee_data;
-               struct sockaddr_in offender;
-       } *err = cmsg_data;
-
-       if (sizeof(*err) > data_len)
-               return;
+       const struct sock_ee *const err = cmsg_data;
 
-       tprintf(", cmsg_data={ee_errno=%u, ee_origin=%u, ee_type=%u, ee_code=%u"
+       tprintf("{ee_errno=%u, ee_origin=%u, ee_type=%u, ee_code=%u"
                ", ee_info=%u, ee_data=%u, offender=",
                err->ee_errno, err->ee_origin, err->ee_type,
                err->ee_code, err->ee_info, err->ee_data);
@@ -191,57 +168,52 @@ print_cmsg_ip_origdstaddr(struct tcb *tcp, const void *cmsg_data,
                data_len > sizeof(struct sockaddr_storage)
                ? sizeof(struct sockaddr_storage) : data_len;
 
-       tprints(", cmsg_data=");
        print_sockaddr(tcp, cmsg_data, addr_len);
 }
 
+typedef void (* const cmsg_printer)(struct tcb *, const void *, size_t);
+
+static const struct {
+       const cmsg_printer printer;
+       const size_t min_len;
+} cmsg_socket_printers[] = {
+       [SCM_RIGHTS] = { print_scm_rights, sizeof(int) },
+       [SCM_CREDENTIALS] = { print_scm_creds, sizeof(struct ucred) },
+       [SCM_SECURITY] = { print_scm_security, 1 }
+}, cmsg_ip_printers[] = {
+       [IP_PKTINFO] = { print_cmsg_ip_pktinfo, sizeof(struct in_pktinfo) },
+       [IP_TTL] = { print_cmsg_uint, sizeof(unsigned int) },
+       [IP_TOS] = { print_cmsg_uint8_t, 1 },
+       [IP_RECVOPTS] = { print_cmsg_ip_opts, 1 },
+       [IP_RETOPTS] = { print_cmsg_ip_opts, 1 },
+       [IP_RECVERR] = { print_cmsg_ip_recverr, sizeof(struct sock_ee) },
+       [IP_ORIGDSTADDR] = { print_cmsg_ip_origdstaddr, sizeof(struct sockaddr_in) },
+       [IP_CHECKSUM] = { print_cmsg_uint, sizeof(unsigned int) },
+       [SCM_SECURITY] = { print_scm_security, 1 }
+};
+
 static void
 print_cmsg_type_data(struct tcb *tcp, const int cmsg_level, const int cmsg_type,
                     const void *cmsg_data, const size_t data_len)
 {
+       const unsigned int utype = cmsg_type;
        switch (cmsg_level) {
        case SOL_SOCKET:
                printxval(scmvals, cmsg_type, "SCM_???");
-               switch (cmsg_type) {
-               case SCM_RIGHTS:
-                       print_scm_rights(tcp, cmsg_data, data_len);
-                       break;
-               case SCM_CREDENTIALS:
-                       print_scm_creds(tcp, cmsg_data, data_len);
-                       break;
-               case SCM_SECURITY:
-                       print_scm_security(tcp, cmsg_data, data_len);
-                       break;
+               if (utype < ARRAY_SIZE(cmsg_socket_printers)
+                   && cmsg_socket_printers[utype].printer
+                   && data_len >= cmsg_socket_printers[utype].min_len) {
+                       tprints(", cmsg_data=");
+                       cmsg_socket_printers[utype].printer(tcp, cmsg_data, data_len);
                }
                break;
        case SOL_IP:
                printxval(ip_cmsg_types, cmsg_type, "IP_???");
-               switch (cmsg_type) {
-               case IP_PKTINFO:
-                       print_cmsg_ip_pktinfo(tcp, cmsg_data, data_len);
-                       break;
-               case IP_TTL:
-                       print_cmsg_uint(tcp, cmsg_data, data_len);
-                       break;
-               case IP_TOS:
-                       print_cmsg_ip_tos(tcp, cmsg_data, data_len);
-                       break;
-               case IP_RECVOPTS:
-               case IP_RETOPTS:
-                       print_cmsg_ip_opts(tcp, cmsg_data, data_len);
-                       break;
-               case IP_RECVERR:
-                       print_cmsg_ip_recverr(tcp, cmsg_data, data_len);
-                       break;
-               case IP_ORIGDSTADDR:
-                       print_cmsg_ip_origdstaddr(tcp, cmsg_data, data_len);
-                       break;
-               case IP_CHECKSUM:
-                       print_cmsg_uint(tcp, cmsg_data, data_len);
-                       break;
-               case SCM_SECURITY:
-                       print_scm_security(tcp, cmsg_data, data_len);
-                       break;
+               if (utype < ARRAY_SIZE(cmsg_ip_printers)
+                   && cmsg_ip_printers[utype].printer
+                   && data_len >= cmsg_ip_printers[utype].min_len) {
+                       tprints(", cmsg_data=");
+                       cmsg_ip_printers[utype].printer(tcp, cmsg_data, data_len);
                }
                break;
        default: