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authorSander Vrijders <sander.vrijders@intec.ugent.be>2016-05-10 18:42:00 +0200
committerSander Vrijders <sander.vrijders@intec.ugent.be>2016-05-10 18:42:00 +0200
commitba8b2ba46a5b499004272c9acc9049539b600082 (patch)
tree857de7ccf8303aba1bc36db56cbf0e7120479913 /src
parentdfda83926c50297d7c315f743b4514f687469c9c (diff)
downloadouroboros-ba8b2ba46a5b499004272c9acc9049539b600082.tar.gz
ouroboros-ba8b2ba46a5b499004272c9acc9049539b600082.zip
ipcpd: Add nslookup to shim UDP
This adds nslookup support to the shim UDP, so that a custom DNS server can be queried.
Diffstat (limited to 'src')
-rw-r--r--src/ipcpd/shim-udp/CMakeLists.txt12
-rw-r--r--src/ipcpd/shim-udp/main.c168
-rw-r--r--src/ipcpd/shim-udp/shim_udp_config.h.in1
3 files changed, 156 insertions, 25 deletions
diff --git a/src/ipcpd/shim-udp/CMakeLists.txt b/src/ipcpd/shim-udp/CMakeLists.txt
index a50fe8bd..e10a8ca6 100644
--- a/src/ipcpd/shim-udp/CMakeLists.txt
+++ b/src/ipcpd/shim-udp/CMakeLists.txt
@@ -40,6 +40,18 @@ if (NOT DISABLE_DNS MATCHES True)
else()
message("-- Found nsupdate: ${NSUPDATE_EXECUTABLE}")
endif()
+
+ # Find the nslookup executable
+ find_program(NSLOOKUP_EXECUTABLE
+ NAMES nslookup
+ DOC "The nslookup tool that resolves DNS names")
+
+ if (${NSLOOKUP_EXECUTABLE} STREQUAL "NSLOOKUP_EXECUTABLE-NOTFOUND")
+ message(FATAL_ERROR
+ "Could not find nslookup, which is needed for DNS resolution")
+ else()
+ message("-- Found nslookup: ${NSLOOKUP_EXECUTABLE}")
+ endif()
endif()
configure_file(
diff --git a/src/ipcpd/shim-udp/main.c b/src/ipcpd/shim-udp/main.c
index b45bee76..bb5c233f 100644
--- a/src/ipcpd/shim-udp/main.c
+++ b/src/ipcpd/shim-udp/main.c
@@ -400,16 +400,22 @@ int ipcp_udp_bootstrap(struct dif_config * conf)
return -1;
}
- inet_ntop(AF_INET,
- &conf->ip_addr,
- ipstr,
- INET_ADDRSTRLEN);
+ if (inet_ntop(AF_INET,
+ &conf->ip_addr,
+ ipstr,
+ INET_ADDRSTRLEN) == NULL) {
+ LOG_ERR("Failed to convert IP address");
+ return -1;
+ }
if (conf->dns_addr != 0) {
- inet_ntop(AF_INET,
- &conf->dns_addr,
- dnsstr,
- INET_ADDRSTRLEN);
+ if (inet_ntop(AF_INET,
+ &conf->dns_addr,
+ dnsstr,
+ INET_ADDRSTRLEN) == NULL) {
+ LOG_ERR("Failed to convert DNS address");
+ return -1;
+ }
#ifndef CONFIG_OUROBOROS_ENABLE_DNS
LOG_WARN("DNS address ignored since shim-udp was "
"compiled without DNS support.");
@@ -478,6 +484,7 @@ int ipcp_udp_bootstrap(struct dif_config * conf)
#ifdef CONFIG_OUROBOROS_ENABLE_DNS
/* FIXME: Dependency on nsupdate to be removed in the end */
+/* NOTE: Disgusted with this crap */
static int ddns_send(char * cmd)
{
pid_t pid = 0;
@@ -506,7 +513,7 @@ static int ddns_send(char * cmd)
close(pipe_fd[0]);
if (write(pipe_fd[1], cmd, strlen(cmd)) == -1) {
- LOG_ERR("Failed to register with DNS server.");
+ LOG_ERR("Failed to communicate with nsupdate.");
close(pipe_fd[1]);
return -1;
}
@@ -521,6 +528,83 @@ static int ddns_send(char * cmd)
close(pipe_fd[1]);
return 0;
}
+
+
+static uint32_t ddns_resolve(char * name, uint32_t dns_addr)
+{
+ pid_t pid = 0;
+ int wstatus;
+ int pipe_fd[2];
+ char dnsstr[INET_ADDRSTRLEN];
+ char buf[SHIM_UDP_BUF_SIZE];
+ ssize_t count = 0;
+ char * substr;
+ char * substr2;
+ char * addr_str = "Address:";
+ uint32_t ip_addr = 0;
+
+ if (inet_ntop(AF_INET, &dns_addr, dnsstr, INET_ADDRSTRLEN) == NULL) {
+ return 0;
+ }
+
+
+ if (pipe(pipe_fd)) {
+ LOG_ERR("Failed to create pipe.");
+ return 0;
+ }
+
+ pid = fork();
+ if (pid == -1) {
+ LOG_ERR("Failed to fork.");
+ return 0;
+ }
+
+ if (pid == 0) {
+ char * argv[] = {NSLOOKUP_EXEC, name, dnsstr, 0};
+ char * envp[] = {0};
+
+ close(pipe_fd[0]);
+ dup2(pipe_fd[1], 1);
+ execve(argv[0], &argv[0], envp);
+ }
+
+ close(pipe_fd[1]);
+
+ count = read(pipe_fd[0], buf, SHIM_UDP_BUF_SIZE);
+ if (count <= 0) {
+ LOG_ERR("Failed to communicate with nslookup.");
+ close(pipe_fd[0]);
+ return 0;
+ }
+
+ close(pipe_fd[0]);
+
+ waitpid(pid, &wstatus, 0);
+ if (WIFEXITED(wstatus) == true &&
+ WEXITSTATUS(wstatus) == 0)
+ LOG_DBGF("Succesfully communicated with nslookup.");
+ else
+ LOG_ERR("Failed to resolve DNS address.");
+
+ buf[count] = '\0';
+ substr = strtok(buf, "\n");
+ while (substr != NULL) {
+ substr2 = substr;
+ substr = strtok(NULL, "\n");
+ }
+
+ if (strstr(substr2, addr_str) == NULL) {
+ LOG_ERR("Failed to resolve DNS address.");
+ return 0;
+ }
+
+ if (inet_pton(AF_INET, substr2 + strlen(addr_str) + 1, &ip_addr) != 1) {
+ LOG_ERR("Failed to resolve DNS address.");
+ return 0;
+ }
+
+ return ip_addr;
+}
#endif
int ipcp_udp_name_reg(char * name)
@@ -556,8 +640,16 @@ int ipcp_udp_name_reg(char * name)
if (dns_addr != 0) {
ip_addr = shim_data(_ipcp)->ip_addr;
- inet_ntop(AF_INET, &ip_addr, ipstr, INET_ADDRSTRLEN);
- inet_ntop(AF_INET, &dns_addr, dnsstr, INET_ADDRSTRLEN);
+ if (inet_ntop(AF_INET, &ip_addr,
+ ipstr, INET_ADDRSTRLEN) == NULL) {
+ return -1;
+ }
+
+ if (inet_ntop(AF_INET, &dns_addr,
+ dnsstr, INET_ADDRSTRLEN) == NULL) {
+ return -1;
+ }
+
sprintf(cmd, "server %s\nupdate add %s %d A %s\nsend\nquit\n",
dnsstr, name, DNS_TTL, ipstr);
@@ -592,7 +684,10 @@ int ipcp_udp_name_unreg(char * name)
dns_addr = shim_data(_ipcp)->dns_addr;
if (dns_addr != 0) {
- inet_ntop(AF_INET, &dns_addr, dnsstr, INET_ADDRSTRLEN);
+ if (inet_ntop(AF_INET, &dns_addr, dnsstr, INET_ADDRSTRLEN)
+ == NULL) {
+ return -1;
+ }
sprintf(cmd, "server %s\nupdate delete %s A\nsend\nquit\n",
dnsstr, name);
@@ -618,11 +713,13 @@ int ipcp_udp_flow_alloc(int port_id,
struct sockaddr_in r_saddr;
struct sockaddr_in rf_saddr;
int fd;
- int n;
-
- char * recv_buf = NULL;
-
- struct hostent * h;
+ int n;
+ char * recv_buf = NULL;
+ struct hostent * h;
+ uint32_t ip_addr = 0;
+#ifdef CONFIG_OUROBOROS_ENABLE_DNS
+ uint32_t dns_addr = 0;
+#endif
if (dst_name == NULL || src_ap_name == NULL || src_ae_name == NULL)
return -1;
@@ -650,22 +747,41 @@ int ipcp_udp_flow_alloc(int port_id,
return -1;
}
- h = gethostbyname(dst_name);
- if (h == NULL) {
- LOG_DBGF("Could not resolve %s.", dst_name);
- close(fd);
- return -1;
+#ifdef CONFIG_OUROBOROS_ENABLE_DNS
+ dns_addr = shim_data(_ipcp)->dns_addr;
+ if (dns_addr != 0) {
+ ip_addr = ddns_resolve(dst_name, dns_addr);
+ if (ip_addr == 0) {
+ LOG_DBGF("Could not resolve %s.", dst_name);
+ close(fd);
+ return -1;
+ }
+ } else {
+#endif
+ h = gethostbyname(dst_name);
+ if (h == NULL) {
+ LOG_DBGF("Could not resolve %s.", dst_name);
+ close(fd);
+ return -1;
+ }
+
+ ip_addr = *((uint32_t *) (h->h_addr_list[0]));
+#ifdef CONFIG_OUROBOROS_ENABLE_DNS
}
+#endif
memset((char *) &r_saddr, 0, sizeof r_saddr);
r_saddr.sin_family = AF_INET;
- r_saddr.sin_addr.s_addr = *((uint32_t *) (h->h_addr_list[0]));
+ r_saddr.sin_addr.s_addr = ip_addr;
r_saddr.sin_port = LISTEN_PORT;
/* at least try to get the packet on the wire */
- while (sendto(fd, dst_name, strlen(dst_name), 0,
+ if (sendto(fd, dst_name, strlen(dst_name), 0,
(struct sockaddr *) &r_saddr, sizeof r_saddr) < 0) {
+ LOG_ERR("Failed to send packet");
+ close(fd);
+ return -1;
}
/* wait for the other shim IPCP to respond */
@@ -683,11 +799,12 @@ int ipcp_udp_flow_alloc(int port_id,
(struct sockaddr *) &rf_saddr,
sizeof rf_saddr)
< 0) {
+ close(fd);
free(recv_buf);
return -1;
}
- if (!strcmp(recv_buf, dst_name))
+ if (strcmp(recv_buf, dst_name))
LOG_WARN("Incorrect echo from server");
free(recv_buf);
@@ -698,6 +815,7 @@ int ipcp_udp_flow_alloc(int port_id,
if (_ap_instance->flows[fd].rb == NULL) {
LOG_ERR("Could not open N + 1 ringbuffer.");
close(fd);
+ return -1;
}
/* tell IRMd that flow allocation "worked" */
diff --git a/src/ipcpd/shim-udp/shim_udp_config.h.in b/src/ipcpd/shim-udp/shim_udp_config.h.in
index 00b0b910..71d269d8 100644
--- a/src/ipcpd/shim-udp/shim_udp_config.h.in
+++ b/src/ipcpd/shim-udp/shim_udp_config.h.in
@@ -24,5 +24,6 @@
#define OUROBOROS_SHIM_UDP_CONFIG
#define NSUPDATE_EXEC "@NSUPDATE_EXECUTABLE@"
+#define NSLOOKUP_EXEC "@NSLOOKUP_EXECUTABLE@"
#endif