Move create_icmp[6]_socket to its only user, and simplify it

function                                             old     new   delta
run_applet_and_exit                                  711     714      +3
sendping_tail                                        239     236      -3
common_ping_main                                    1798    1770     -28
create_icmp_socket                                    65       -     -65
create_icmp6_socket                                   65       -     -65
------------------------------------------------------------------------------
(add/remove: 0/4 grow/shrink: 1/2 up/down: 3/-161)           Total: -158 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

5 files changed, 44 insertions, 99 deletions

diff --git a/include/libbb.h b/include/libbb.h
index 65c6b9f39..085210431 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -1109,9 +1109,6 @@ void bb_displayroutes(int noresolve, int netstatfmt) FAST_FUNC;
 
 
 /* Networking */
-int create_icmp_socket(void) FAST_FUNC;
-int create_icmp6_socket(void) FAST_FUNC;
-/* interface.c */
 /* This structure defines protocol families and their handlers. */
 struct aftype {
         const char *name;
diff --git a/libbb/Kbuild.src b/libbb/Kbuild.src
index 61eec26f7..c5d86c092 100644
--- a/libbb/Kbuild.src
+++ b/libbb/Kbuild.src
@@ -27,8 +27,6 @@ lib-y += concat_subpath_file.o
 lib-y += copy_file.o
 lib-y += copyfd.o
 lib-y += crc32.o
-lib-y += create_icmp6_socket.o
-lib-y += create_icmp_socket.o
 lib-y += default_error_retval.o
 lib-y += device_open.o
 lib-y += dump.o
diff --git a/libbb/create_icmp6_socket.c b/libbb/create_icmp6_socket.c
deleted file mode 100644
index 368c69028..000000000
--- a/libbb/create_icmp6_socket.c
+++ /dev/null
@@ -1,38 +0,0 @@
-/* vi: set sw=4 ts=4: */
-/*
- * Utility routines.
- *
- * create raw socket for icmp (IPv6 version) protocol
- * and drop root privileges if running setuid
- *
- * Licensed under GPLv2, see file LICENSE in this source tree.
- */
-
-#include "libbb.h"
-
-#if ENABLE_FEATURE_IPV6
-int FAST_FUNC create_icmp6_socket(void)
-{
-        int sock;
-#if 0
-        struct protoent *proto;
-        proto = getprotobyname("ipv6-icmp");
-        /* if getprotobyname failed, just silently force
-         * proto->p_proto to have the correct value for "ipv6-icmp" */
-        sock = socket(AF_INET6, SOCK_RAW,
-                        (proto ? proto->p_proto : IPPROTO_ICMPV6));
-#else
-        sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6);
-#endif
-        if (sock < 0) {
-                if (errno == EPERM)
-                        bb_error_msg_and_die(bb_msg_perm_denied_are_you_root);
-                bb_perror_msg_and_die(bb_msg_can_not_create_raw_socket);
-        }
-
-        /* drop root privs if running setuid */
-        xsetuid(getuid());
-
-        return sock;
-}
-#endif
diff --git a/libbb/create_icmp_socket.c b/libbb/create_icmp_socket.c
deleted file mode 100644
index 585626983..000000000
--- a/libbb/create_icmp_socket.c
+++ /dev/null
@@ -1,36 +0,0 @@
-/* vi: set sw=4 ts=4: */
-/*
- * Utility routines.
- *
- * create raw socket for icmp protocol
- * and drop root privileges if running setuid
- *
- * Licensed under GPLv2, see file LICENSE in this source tree.
- */
-
-#include "libbb.h"
-
-int FAST_FUNC create_icmp_socket(void)
-{
-        int sock;
-#if 0
-        struct protoent *proto;
-        proto = getprotobyname("icmp");
-        /* if getprotobyname failed, just silently force
-         * proto->p_proto to have the correct value for "icmp" */
-        sock = socket(AF_INET, SOCK_RAW,
-                        (proto ? proto->p_proto : 1)); /* 1 == ICMP */
-#else
-        sock = socket(AF_INET, SOCK_RAW, 1); /* 1 == ICMP */
-#endif
-        if (sock < 0) {
-                if (errno == EPERM)
-                        bb_error_msg_and_die(bb_msg_perm_denied_are_you_root);
-                bb_perror_msg_and_die(bb_msg_can_not_create_raw_socket);
-        }
-
-        /* drop root privs if running setuid */
-        xsetuid(getuid());
-
-        return sock;
-}
diff --git a/networking/ping.c b/networking/ping.c
index e919b3a09..8c08c8074 100644
--- a/networking/ping.c
+++ b/networking/ping.c
@@ -149,8 +149,33 @@ enum {
         MAX_DUP_CHK = (8 * 128),
         MAXWAIT = 10,
         PINGINTERVAL = 1, /* 1 second */
+        pingsock = 0,
 };
 
+static void
+#if ENABLE_PING6
+create_icmp_socket(len_and_sockaddr *lsa)
+#else
+create_icmp_socket(void)
+#define create_icmp_socket(lsa) create_icmp_socket()
+#endif
+{
+        int sock;
+#if ENABLE_PING6
+        if (lsa->u.sa.sa_family == AF_INET6)
+                sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6);
+        else
+#endif
+                sock = socket(AF_INET, SOCK_RAW, 1); /* 1 == ICMP */
+        if (sock < 0) {
+                if (errno == EPERM)
+                        bb_error_msg_and_die(bb_msg_perm_denied_are_you_root);
+                bb_perror_msg_and_die(bb_msg_can_not_create_raw_socket);
+        }
+
+        xmove_fd(sock, pingsock);
+}
+
 #if !ENABLE_FEATURE_FANCY_PING
 
 /* Simple version */
@@ -171,12 +196,10 @@ static void noresp(int ign UNUSED_PARAM)
 static void ping4(len_and_sockaddr *lsa)
 {
         struct icmp *pkt;
-        int pingsock, c;
-
-        pingsock = create_icmp_socket();
+        int c;
 
         pkt = (struct icmp *) G.packet;
-        memset(pkt, 0, sizeof(G.packet));
+        /*memset(pkt, 0, sizeof(G.packet)); already is */
         pkt->icmp_type = ICMP_ECHO;
         pkt->icmp_cksum = inet_cksum((uint16_t *) pkt, sizeof(G.packet));
 
@@ -184,11 +207,15 @@ static void ping4(len_and_sockaddr *lsa)
 
         /* listen for replies */
         while (1) {
+#if 0
                 struct sockaddr_in from;
                 socklen_t fromlen = sizeof(from);
 
                 c = recvfrom(pingsock, G.packet, sizeof(G.packet), 0,
                                 (struct sockaddr *) &from, &fromlen);
+#else
+                c = recv(pingsock, G.packet, sizeof(G.packet), 0);
+#endif
                 if (c < 0) {
                         if (errno != EINTR)
                                 bb_perror_msg("recvfrom");
@@ -210,13 +237,11 @@ static void ping4(len_and_sockaddr *lsa)
 static void ping6(len_and_sockaddr *lsa)
 {
         struct icmp6_hdr *pkt;
-        int pingsock, c;
+        int c;
         int sockopt;
 
-        pingsock = create_icmp6_socket();
-
         pkt = (struct icmp6_hdr *) G.packet;
-        memset(pkt, 0, sizeof(G.packet));
+        /*memset(pkt, 0, sizeof(G.packet)); already is */
         pkt->icmp6_type = ICMP6_ECHO_REQUEST;
 
         sockopt = offsetof(struct icmp6_hdr, icmp6_cksum);
@@ -226,18 +251,21 @@ static void ping6(len_and_sockaddr *lsa)
 
         /* listen for replies */
         while (1) {
+#if 0
                 struct sockaddr_in6 from;
                 socklen_t fromlen = sizeof(from);
 
                 c = recvfrom(pingsock, G.packet, sizeof(G.packet), 0,
                                 (struct sockaddr *) &from, &fromlen);
+#else
+                c = recv(pingsock, G.packet, sizeof(G.packet), 0);
+#endif
                 if (c < 0) {
                         if (errno != EINTR)
                                 bb_perror_msg("recvfrom");
                         continue;
                 }
-                if (c >= ICMP_MINLEN) {                 /* icmp6_hdr */
-                        pkt = (struct icmp6_hdr *) G.packet;
+                if (c >= ICMP_MINLEN) { /* icmp6_hdr */
                         if (pkt->icmp6_type == ICMP6_ECHO_REPLY)
                                 break;
                 }
@@ -285,6 +313,7 @@ static int common_ping_main(sa_family_t af, char **argv)
         signal(SIGALRM, noresp);
         alarm(5); /* give the host 5000ms to respond */
 
+        create_icmp_socket(lsa);
 #if ENABLE_PING6
         if (lsa->u.sa.sa_family == AF_INET6)
                 ping6(lsa);
@@ -318,7 +347,6 @@ enum {
 
 
 struct globals {
-        int pingsock;
         int if_index;
         char *str_I;
         len_and_sockaddr *source_lsa;
@@ -347,7 +375,6 @@ struct globals {
         char rcvd_tbl[MAX_DUP_CHK / 8];
 } FIX_ALIASING;
 #define G (*(struct globals*)&bb_common_bufsiz1)
-#define pingsock     (G.pingsock    )
 #define if_index     (G.if_index    )
 #define source_lsa   (G.source_lsa  )
 #define str_I        (G.str_I       )
@@ -369,7 +396,6 @@ void BUG_ping_globals_too_big(void);
 #define INIT_G() do { \
         if (sizeof(G) > COMMON_BUFSIZE) \
                 BUG_ping_globals_too_big(); \
-        pingsock = -1; \
         datalen = DEFDATALEN; \
         timeout = MAXWAIT; \
         tmin = UINT_MAX; \
@@ -655,7 +681,6 @@ static void ping4(len_and_sockaddr *lsa)
 {
         int sockopt;
 
-        pingsock = create_icmp_socket();
         pingaddr.sin = lsa->u.sin;
         if (source_lsa) {
                 if (setsockopt(pingsock, IPPROTO_IP, IP_MULTICAST_IF,
@@ -663,8 +688,6 @@ static void ping4(len_and_sockaddr *lsa)
                         bb_error_msg_and_die("can't set multicast source interface");
                 xbind(pingsock, &source_lsa->u.sa, source_lsa->len);
         }
-        if (str_I)
-                setsockopt_bindtodevice(pingsock, str_I);
 
         /* enable broadcast pings */
         setsockopt_broadcast(pingsock);
@@ -713,13 +736,9 @@ static void ping6(len_and_sockaddr *lsa)
         struct iovec iov;
         char control_buf[CMSG_SPACE(36)];
 
-        pingsock = create_icmp6_socket();
         pingaddr.sin6 = lsa->u.sin6;
-        /* untested whether "-I addr" really works for IPv6: */
         if (source_lsa)
                 xbind(pingsock, &source_lsa->u.sa, source_lsa->len);
-        if (str_I)
-                setsockopt_bindtodevice(pingsock, str_I);
 
 #ifdef ICMP6_FILTER
         {
@@ -806,6 +825,11 @@ static void ping(len_and_sockaddr *lsa)
         }
         printf(": %d data bytes\n", datalen);
 
+        create_icmp_socket(lsa);
+        /* untested whether "-I addr" really works for IPv6: */
+        if (str_I)
+                setsockopt_bindtodevice(pingsock, str_I);
+
         G.sizeof_rcv_packet = datalen + MAXIPLEN + MAXICMPLEN;
         G.rcv_packet = xzalloc(G.sizeof_rcv_packet);
 #if ENABLE_PING6