Bug Summary

File:src/usr.sbin/dvmrpd/kmroute.c
Warning:line 97, column 7
Although the value stored to 'r' is used in the enclosing expression, the value is never actually read from 'r'

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name kmroute.c -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 1 -pic-is-pie -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/usr.sbin/dvmrpd/obj -resource-dir /usr/local/lib/clang/13.0.0 -I /usr/src/usr.sbin/dvmrpd -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/usr.sbin/dvmrpd/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/vmm/scan-build/2022-01-12-194120-40624-1 -x c /usr/src/usr.sbin/dvmrpd/kmroute.c
1/* $OpenBSD: kmroute.c,v 1.3 2019/06/28 13:32:47 deraadt Exp $ */
2
3/*
4 * Copyright (c) 2005, 2006 Esben Norby <norby@openbsd.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19#include <sys/types.h>
20#include <sys/socket.h>
21#include <netinet/in.h>
22#include <arpa/inet.h>
23#include <netinet/ip_mroute.h>
24
25#include <err.h>
26#include <errno(*__errno()).h>
27#include <stdlib.h>
28#include <string.h>
29
30#include "igmp.h"
31#include "dvmrpd.h"
32#include "dvmrp.h"
33#include "dvmrpe.h"
34#include "log.h"
35
36extern struct dvmrpd_conf *conf;
37char *mroute_ptr; /* packet buffer */
38
39void main_imsg_compose_rde(int, pid_t, void *, u_int16_t);
40
41int
42kmr_init(int fd)
43{
44 struct iface *iface;
45 struct route_report rr;
46
47 LIST_FOREACH(iface, &conf->iface_list, entry)for((iface) = ((&conf->iface_list)->lh_first); (iface
)!= ((void *)0); (iface) = ((iface)->entry.le_next)) {
48 log_debug("kmr_init: interface %s", iface->name);
49
50 rr.net.s_addr = iface->addr.s_addr & iface->mask.s_addr;
51 rr.mask = iface->mask;
52 rr.nexthop.s_addr = 0;
53 rr.metric = iface->metric;
54 rr.ifindex = iface->ifindex;
55 main_imsg_compose_rde(IMSG_ROUTE_REPORT, -1, &rr, sizeof(rr));
56
57 mrt_add_vif(conf->mroute_socket, iface);
58 }
59
60 if ((mroute_ptr = calloc(1, IBUF_READ_SIZE65535)) == NULL((void *)0))
61 fatal("kmr_init");
62
63 return (0);
64}
65
66void
67kmr_shutdown(void)
68{
69 struct iface *iface;
70
71 kmr_mfc_decouple();
72 kmroute_clear();
73
74 LIST_FOREACH(iface, &conf->iface_list, entry)for((iface) = ((&conf->iface_list)->lh_first); (iface
)!= ((void *)0); (iface) = ((iface)->entry.le_next)) {
75 log_debug("kmr_shutdown: interface %s", iface->name);
76
77 mrt_del_vif(conf->mroute_socket, iface);
78 }
79
80 free(mroute_ptr);
81}
82
83void
84kmr_recv_msg(int fd, short event, void *bula)
85{
86 struct mfc mfc;
87 struct igmpmsg kernel_msg;
88 char *buf;
89 ssize_t r;
90
91 if (event != EV_READ0x02)
92 return;
93
94 /* setup buffer */
95 buf = mroute_ptr;
96
97 if ((r = recvfrom(fd, buf, IBUF_READ_SIZE65535, 0, NULL((void *)0), NULL((void *)0))) == -1) {
Although the value stored to 'r' is used in the enclosing expression, the value is never actually read from 'r'
98 if (errno(*__errno()) != EAGAIN35 && errno(*__errno()) != EINTR4)
99 log_debug("kmr_recv_msg: error receiving packet");
100 return;
101 }
102
103 memcpy(&kernel_msg, buf, sizeof(kernel_msg));
104
105 /* we are only interested in kernel messages */
106 if (kernel_msg.im_mbz != 0)
107 return;
108
109 switch (kernel_msg.im_msgtype) {
110 case IGMPMSG_NOCACHE1:
111 /* verify that dst is a multicast group */
112 if (!IN_MULTICAST(ntohl(kernel_msg.im_dst.s_addr))(((u_int32_t)((__uint32_t)(__builtin_constant_p(kernel_msg.im_dst
.s_addr) ? (__uint32_t)(((__uint32_t)(kernel_msg.im_dst.s_addr
) & 0xff) << 24 | ((__uint32_t)(kernel_msg.im_dst.s_addr
) & 0xff00) << 8 | ((__uint32_t)(kernel_msg.im_dst.
s_addr) & 0xff0000) >> 8 | ((__uint32_t)(kernel_msg
.im_dst.s_addr) & 0xff000000) >> 24) : __swap32md(kernel_msg
.im_dst.s_addr))) & ((u_int32_t)(0xf0000000))) == ((u_int32_t
)(0xe0000000)))) {
113 log_debug("kmr_recv_msg: kernel providing garbage!");
114 return;
115 }
116
117 /* send MFC entry to RDE */
118 mfc.origin = kernel_msg.im_src;
119 mfc.group = kernel_msg.im_dst;
120 mfc.ifindex = kernel_msg.im_vif;
121 main_imsg_compose_rde(IMSG_MFC_ADD, 0, &mfc, sizeof(mfc));
122 break;
123 case IGMPMSG_WRONGVIF2:
124 case IGMPMSG_WHOLEPKT3:
125 case IGMPMSG_BW_UPCALL4:
126 default:
127 log_debug("kmr_recv_msg: unhandled msg type %d!",
128 kernel_msg.im_msgtype);
129 }
130}
131
132void
133kmr_mfc_couple(void)
134{
135 log_info("kernel multicast forwarding cache coupled");
136}
137
138void
139kmr_mfc_decouple(void)
140{
141 log_info("kernel multicast forwarding cache decoupled");
142}
143
144void
145kmroute_clear(void)
146{
147
148}
149
150int
151mrt_init(int fd)
152{
153 int flag = 1;
154
155 if (setsockopt(fd, IPPROTO_IP0, MRT_INIT100, &flag,
156 sizeof(flag)) == -1) {
157 log_warn("mrt_init: error setting MRT_INIT");
158 return (-1);
159 }
160
161 return (0);
162}
163
164int
165mrt_done(int fd)
166{
167 int flag = 0;
168
169 if (setsockopt(fd, IPPROTO_IP0, MRT_DONE101, &flag,
170 sizeof(flag)) == -1) {
171 log_warn("mrt_done: error setting MRT_DONE");
172 return (-1);
173 }
174
175 return (0);
176}
177
178int
179mrt_add_vif(int fd, struct iface *iface)
180{
181 struct vifctl vc;
182
183 vc.vifc_vifi = iface->ifindex;
184 vc.vifc_flags = 0;
185 vc.vifc_threshold = 1;
186 vc.vifc_rate_limit = 0;
187 vc.vifc_lcl_addr.s_addr = iface->addr.s_addr;
188 vc.vifc_rmt_addr.s_addr = 0;
189
190 if (setsockopt(fd, IPPROTO_IP0, MRT_ADD_VIF102, &vc,
191 sizeof(vc)) == -1) {
192 log_warn("mrt_add_vif: error adding VIF");
193 return (-1);
194 }
195
196 return (0);
197}
198
199void
200mrt_del_vif(int fd, struct iface *iface)
201{
202 vifi_t vifi;
203
204 vifi = iface->ifindex;
205
206 if (setsockopt(fd, IPPROTO_IP0, MRT_DEL_VIF103, &vifi,
207 sizeof(vifi)) == -1)
208 log_warn("mrt_del_vif: error deleting VIF");
209}
210
211int
212mrt_add_mfc(int fd, struct mfc *mfc)
213{
214 struct mfcctl mc;
215 int i;
216
217 log_debug("mrt_add_mfc: interface %d, group %s", mfc->ifindex,
218 inet_ntoa(mfc->group));
219
220 mc.mfcc_origin = mfc->origin;
221 mc.mfcc_mcastgrp = mfc->group;
222 mc.mfcc_parent = mfc->ifindex;
223
224 for (i = 0; i < MAXVIFS32; i++) {
225 mc.mfcc_ttls[i] = mfc->ttls[i];
226 }
227
228 if (setsockopt(fd, IPPROTO_IP0, MRT_ADD_MFC104, &mc, sizeof(mc))
229 == -1) {
230 log_warnx("mrt_add_mfc: error adding group %s to interface %d",
231 inet_ntoa(mfc->group), mfc->ifindex);
232 return (-1);
233 }
234
235 return (0);
236}
237
238int
239mrt_del_mfc(int fd, struct mfc *mfc)
240{
241 struct mfcctl mc;
242
243 log_debug("mrt_del_mfc: group %s", inet_ntoa(mfc->group));
244
245 mc.mfcc_origin = mfc->origin;
246 mc.mfcc_mcastgrp = mfc->group;
247
248 if (setsockopt(fd, IPPROTO_IP0, MRT_DEL_MFC105, &mc, sizeof(mc))
249 == -1) {
250 log_warnx("mrt_del_mfc: error deleting group %s ",
251 inet_ntoa(mfc->group));
252 return (-1);
253 }
254
255 return (0);
256}