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spartclientudp.c (2518B)
1 // Usage: spartclient hostname port path
2 #include <stdio.h>
3 #include <sys/types.h>
4 #include <sys/socket.h>
5 #include <netdb.h>
6 #include <netinet/in.h>
7 #include <string.h>
8 #include <stdlib.h>
9 #include <ctype.h>
10 #include <unistd.h>
11
12 int64_t parseInt(const char *string) {
13 while (!isdigit(*string) && *string != '-' && *string != 0) {
14 string++;
15 }
16 int64_t r = strtoll(string, NULL, 10);
17 return(r);
18 }
19
20 int main(int ac, char **av){
21 int sock;
22 struct sockaddr_in server;
23 struct hostent *hp;
24 int mysock;
25 char buf[65536] = {0};
26 int rval;
27 int i;
28
29 if (ac < 4) {
30 puts("Usage: spartclient hostname port path");
31 return 0;
32 }
33
34 sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
35 if (sock < 0){
36 perror("Failed to create socket");
37 }
38
39 server.sin_family = AF_INET;
40
41 hp = gethostbyname(av[1]);
42 if (hp==0) {
43 perror("gethostbyname failed");
44 close(sock);
45 exit(1);
46 }
47
48 memcpy(&server.sin_addr, hp->h_addr, hp->h_length);
49
50 int64_t port = parseInt(av[2]);
51
52 if (port < 1 || port > 65000) {
53 printf("Invalid port %d.\n", port);
54 return 1;
55 }
56
57 server.sin_port = htons(port);
58
59 // open socket for response
60 struct sockaddr_in respaddr;
61 int rsock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
62 if (rsock < 0){
63 perror("Failed to create socket");
64 }
65
66 respaddr.sin_family = AF_INET;
67 respaddr.sin_addr.s_addr = INADDR_ANY;
68 respaddr.sin_port = htons(port);
69
70 if (bind(rsock, (struct sockaddr *) &respaddr, sizeof(respaddr))){
71 perror("bind failed");
72 exit(1);
73 }
74
75 // build request
76 size_t len = strlen(av[1]);
77 memcpy(buf, av[1], len);
78 buf[len] = ' ';
79 char *cursor = buf + len + 1;
80 len = strlen(av[3]);
81 memcpy(cursor, av[3], len);
82 memcpy(cursor + len, " 0\r\n", strlen(" 0\r\n"));
83 cursor += len + strlen(" 0\r\n");
84
85 // send request
86 if (sendto(sock, buf, cursor - buf, 0, (const struct sockaddr *)&server, sizeof(server)) < 0) {
87 perror("send failed");
88 close(sock);
89 exit(1);
90 }
91 close(sock);
92
93 // reveice server response
94 struct sockaddr_in addr;
95 socklen_t ln = sizeof(addr);
96 rval = recvfrom(rsock, buf, sizeof(buf)-1/* -1 to add end of string before printing */, 0, (struct sockaddr *) &addr, &ln);
97 close(rsock);
98 if (addr.sin_addr.s_addr == server.sin_addr.s_addr && rval != -1 && rval != 0) {
99 buf[rval] = 0;
100 puts(buf);
101 }
102 }
103