1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
|
From 21d74f2989d0046e5b7c586f5a052643d5da8dcc Mon Sep 17 00:00:00 2001
From: Natanael Copa <ncopa@alpinelinux.org>
Date: Tue, 29 Mar 2016 18:59:22 +0200
Subject: [PATCH 06/16] ping: make ping work without root privileges
---
networking/ping.c | 103 +++++++++++++++++++++++++++++++++++++++++++++---------
1 file changed, 87 insertions(+), 16 deletions(-)
diff --git a/networking/ping.c b/networking/ping.c
index d1d59d545..c0ebc0f9a 100644
--- a/networking/ping.c
+++ b/networking/ping.c
@@ -163,6 +163,7 @@ enum {
pingsock = 0,
};
+static int using_dgram;
static void
#if ENABLE_PING6
create_icmp_socket(len_and_sockaddr *lsa)
@@ -179,9 +180,23 @@ create_icmp_socket(void)
#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);
+ if (errno != EPERM)
+ bb_perror_msg_and_die(bb_msg_can_not_create_raw_socket);
+#if defined(__linux__) || defined(__APPLE__)
+ /* We don't have root privileges. Try SOCK_DGRAM instead.
+ * Linux needs net.ipv4.ping_group_range for this to work.
+ * MacOSX allows ICMP_ECHO, ICMP_TSTAMP or ICMP_MASKREQ
+ */
+#if ENABLE_PING6
+ if (lsa->u.sa.sa_family == AF_INET6)
+ sock = socket(AF_INET6, SOCK_DGRAM, IPPROTO_ICMPV6);
+ else
+#endif
+ sock = socket(AF_INET, SOCK_DGRAM, 1); /* 1 == ICMP */
+ if (sock < 0)
+#endif
+ bb_error_msg_and_die(bb_msg_perm_denied_are_you_root);
+ using_dgram = 1;
}
xmove_fd(sock, pingsock);
@@ -234,10 +249,12 @@ static void ping4(len_and_sockaddr *lsa)
bb_perror_msg("recvfrom");
continue;
}
- if (c >= 76) { /* ip + icmp */
- struct iphdr *iphdr = (struct iphdr *) G.packet;
+ if (c >= 76 || using_dgram && (c == 64)) { /* ip + icmp */
+ if(!using_dgram) {
+ struct iphdr *iphdr = (struct iphdr *) G.packet;
- pkt = (struct icmp *) (G.packet + (iphdr->ihl << 2)); /* skip ip hdr */
+ pkt = (struct icmp *) (G.packet + (iphdr->ihl << 2)); /* skip ip hdr */
+ } else pkt = (struct icmp *) G.packet;
if (pkt->icmp_id != G.myid)
continue; /* not our ping */
if (pkt->icmp_type == ICMP_ECHOREPLY)
@@ -634,19 +651,21 @@ static void unpack_tail(int sz, uint32_t *tp,
}
static void unpack4(char *buf, int sz, struct sockaddr_in *from)
{
- struct icmp *icmppkt;
struct iphdr *iphdr;
+ struct icmp *icmppkt;
int hlen;
/* discard if too short */
if (sz < (datalen + ICMP_MINLEN))
return;
+ if(!using_dgram) {
+ /* check IP header */
+ iphdr = (struct iphdr *) buf;
+ hlen = iphdr->ihl << 2;
+ sz -= hlen;
+ icmppkt = (struct icmp *) (buf + hlen);
+ } else icmppkt = (struct icmp *) buf;
- /* check IP header */
- iphdr = (struct iphdr *) buf;
- hlen = iphdr->ihl << 2;
- sz -= hlen;
- icmppkt = (struct icmp *) (buf + hlen);
if (icmppkt->icmp_id != myid)
return; /* not our ping */
@@ -658,7 +677,7 @@ static void unpack4(char *buf, int sz, struct sockaddr_in *from)
tp = (uint32_t *) icmppkt->icmp_data;
unpack_tail(sz, tp,
inet_ntoa(*(struct in_addr *) &from->sin_addr.s_addr),
- recv_seq, iphdr->ttl);
+ recv_seq, using_dgram ? 42 : iphdr->ttl);
} else if (icmppkt->icmp_type != ICMP_ECHO) {
bb_error_msg("warning: got ICMP %d (%s)",
icmppkt->icmp_type,
@@ -702,11 +721,31 @@ static void ping4(len_and_sockaddr *lsa)
int sockopt;
pingaddr.sin = lsa->u.sin;
- if (source_lsa) {
+ if (source_lsa && !using_dgram) {
if (setsockopt(pingsock, IPPROTO_IP, IP_MULTICAST_IF,
&source_lsa->u.sa, source_lsa->len))
bb_error_msg_and_die("can't set multicast source interface");
xbind(pingsock, &source_lsa->u.sa, source_lsa->len);
+ } else if(using_dgram) {
+ struct sockaddr_in sa;
+ socklen_t sl;
+
+ sa.sin_family = AF_INET;
+ sa.sin_port = 0;
+ sa.sin_addr.s_addr = source_lsa ?
+ source_lsa->u.sin.sin_addr.s_addr : 0;
+ sl = sizeof(sa);
+
+ if (bind(pingsock, (struct sockaddr *) &sa, sl) == -1) {
+ perror("bind");
+ exit(2);
+ }
+
+ if (getsockname(pingsock, (struct sockaddr *) &sa, &sl) == -1) {
+ perror("getsockname");
+ exit(2);
+ }
+ myid = sa.sin_port;
}
/* enable broadcast pings */
@@ -723,6 +762,15 @@ static void ping4(len_and_sockaddr *lsa)
setsockopt_int(pingsock, IPPROTO_IP, IP_MULTICAST_TTL, opt_ttl);
}
+ if(using_dgram) {
+ int hold = 65536;
+ if (setsockopt(pingsock, SOL_IP, IP_RECVTTL, (char *)&hold, sizeof(hold)))
+ perror("WARNING: setsockopt(IP_RECVTTL)");
+ if (setsockopt(pingsock, SOL_IP, IP_RETOPTS, (char *)&hold, sizeof(hold)))
+ perror("WARNING: setsockopt(IP_RETOPTS)");
+
+ }
+
signal(SIGINT, print_stats_and_exit);
/* start the ping's going ... */
@@ -756,10 +804,33 @@ static void ping6(len_and_sockaddr *lsa)
char control_buf[CMSG_SPACE(36)];
pingaddr.sin6 = lsa->u.sin6;
- if (source_lsa)
+ if (source_lsa && !using_dgram)
xbind(pingsock, &source_lsa->u.sa, source_lsa->len);
+ else if(using_dgram) {
+ struct sockaddr_in6 sa = {0};
+ socklen_t sl;
+
+ sa.sin6_family = AF_INET6;
+ sa.sin6_port = 0;
+ if(source_lsa) {
+ memcpy(&sa.sin6_addr, &source_lsa->u.sin6.sin6_addr, sizeof(struct in6_addr));
+ }
+ sl = sizeof(sa);
+
+ if (bind(pingsock, (struct sockaddr *) &sa, sl) == -1) {
+ perror("bind");
+ exit(2);
+ }
+
+ if (getsockname(pingsock, (struct sockaddr *) &sa, &sl) == -1) {
+ perror("getsockname");
+ exit(2);
+ }
+ myid = sa.sin6_port;
+ }
#ifdef ICMP6_FILTER
+ if(!using_dgram)
{
struct icmp6_filter filt;
if (!(option_mask32 & OPT_VERBOSE)) {
@@ -890,7 +961,7 @@ static int common_ping_main(int opt, char **argv)
if (opt & OPT_p)
G.pattern = xstrtou_range(str_p, 16, 0, 255);
- myid = (uint16_t) getpid();
+ if (!using_dgram) myid = (uint16_t) getpid();
hostname = argv[optind];
#if ENABLE_PING6
{
--
2.16.2
|
