tinywebd

view src/main.c @ 1:f425a9805d17

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foo
author John Tsiombikas <nuclear@member.fsf.org>
date Tue, 14 Apr 2015 08:32:51 +0300
parents 9c9e24956d99
children 852a745503cf
line source
1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <string.h>
4 #include <errno.h>
5 #include <unistd.h>
6 #include <fcntl.h>
7 #include <sys/select.h>
8 #include <sys/types.h>
9 #include <sys/socket.h>
10 #include <arpa/inet.h>
11 #include "http.h"
12
13 /* HTTP version */
14 #define HTTP_VER_MAJOR 1
15 #define HTTP_VER_MINOR 1
16 #define HTTP_VER_STR "1.1"
17
18 /* maximum request length: 64mb */
19 #define MAX_REQ_LENGTH (65536 * 1024)
20
21 struct client {
22 int s;
23 char *rcvbuf;
24 int bufsz;
25 struct client *next;
26 };
27
28 int start_server(void);
29 int accept_conn(int lis);
30 int handle_client(struct client *c);
31 void respond_error(struct client *c, int errcode);
32 int parse_args(int argc, char **argv);
33
34 static int lis;
35 static int port = 8080;
36 static struct client *clist;
37
38 int main(int argc, char **argv)
39 {
40 if(parse_args(argc, argv) == -1) {
41 return 1;
42 }
43
44 if((lis = start_server()) == -1) {
45 return 1;
46 }
47
48 for(;;) {
49 struct client *c, dummy;
50 int maxfd = lis;
51 fd_set rdset;
52
53 FD_ZERO(&rdset);
54 FD_SET(lis, &rdset);
55
56 c = clist;
57 while(c) {
58 if(c->s > maxfd) {
59 maxfd = c->s;
60 }
61 FD_SET(c->s, &rdset);
62 c = c->next;
63 }
64
65 while(select(maxfd + 1, &rdset, 0, 0, 0) == -1 && errno == EINTR);
66
67 c = clist;
68 while(c) {
69 if(FD_ISSET(c->s, &rdset)) {
70 handle_client(c);
71 }
72 c = c->next;
73 }
74
75 if(FD_ISSET(lis, &rdset)) {
76 accept_conn(lis);
77 }
78
79 dummy.next = clist;
80 c = &dummy;
81
82 while(c->next) {
83 struct client *n = c->next;
84
85 if(n->s == -1) {
86 /* marked for removal */
87 c->next = n->next;
88 free(n);
89 } else {
90 c = c->next;
91 }
92 }
93 }
94 }
95
96 int start_server(void)
97 {
98 int s;
99 struct sockaddr_in sa;
100
101 if((s = socket(PF_INET, SOCK_STREAM, 0)) == -1) {
102 perror("failed to create listening socket");
103 return -1;
104 }
105 fcntl(s, F_SETFL, fcntl(s, F_GETFL) | O_NONBLOCK);
106
107 memset(&sa, 0, sizeof sa);
108 sa.sin_family = AF_INET;
109 sa.sin_addr.s_addr = INADDR_ANY;
110 sa.sin_port = htons(port);
111
112 if(bind(s, (struct sockaddr*)&sa, sizeof sa) == -1) {
113 fprintf(stderr, "failed to bind socket to port %d: %s\n", port, strerror(errno));
114 return -1;
115 }
116 listen(s, 16);
117
118 return s;
119 }
120
121 int accept_conn(int lis)
122 {
123 int s;
124 struct client *c;
125 struct sockaddr_in addr;
126 socklen_t addr_sz = sizeof addr;
127
128 if((s = accept(lis, (struct sockaddr*)&addr, &addr_sz)) == -1) {
129 perror("failed to accept incoming connection");
130 return -1;
131 }
132 fcntl(s, F_SETFL, fcntl(s, F_GETFL) | O_NONBLOCK);
133
134 if(!(c = malloc(sizeof *c))) {
135 perror("failed to allocate memory while accepting connection");
136 return -1;
137 }
138 c->s = s;
139 c->rcvbuf = 0;
140 c->bufsz = 0;
141 c->next = clist;
142 clist = c;
143 return 0;
144 }
145
146 void close_conn(struct client *c)
147 {
148 close(c->s);
149 c->s = -1; /* mark it for removal */
150 free(c->rcvbuf);
151 }
152
153 static char *skip_space(char *s, char *endp)
154 {
155 while(s < endp && *s && isspace(*s))
156 ++s;
157 return s;
158 }
159
160 int handle_client(struct client *c)
161 {
162 char *reqp, *hdrp, *bodyp, *endp, *eol;
163 char req_type[32];
164 static char buf[2048];
165 int rdsz;
166
167 while((rdsz = recv(c->s, buf, sizeof buf, 0)) > 0) {
168 if(c->rcvbuf) {
169 int newsz = c->bufsz + rdsz;
170 if(newsz > MAX_REQ_LENGTH) {
171 respond_error(c, 413);
172 return -1;
173 }
174
175 char *newbuf = realloc(buf, newsz + 1);
176 if(!newbuf) {
177 fprintf(stderr, "failed to allocate %d byte buffer\n", newsz);
178 respond_error(c, 503);
179 return -1;
180 }
181
182 memcpy(newbuf + c->bufsz, buf, rdsz);
183 newbuf[newsz] = 0;
184
185 c->rcvbuf = newbuf;
186 c->bufsz = newsz;
187 }
188 }
189
190 endp = c->rcvbuf + c->bufsz;
191 if((reqp = skip_space(buf, endp)) >= endp) {
192 return 0; /* incomplete have to read more ... */
193 }
194
195
196 /* we only support GET and HEAD at this point, so freak out on anything else */
197
198 /* TODO: parse header, drop on invalid, determine if the request
199 * is complete and process
200 */
201 }
202
203 void respond_error(struct client *c, int errcode)
204 {
205 char buf[512];
206
207 sprintf(buf, HTTP_VER_STR " %d %s\r\n\r\n", errcode, http_strmsg(errcode));
208
209 send(c->s, buf, strlen(buf), 0);
210 close_conn(c);
211 }
212
213
214 static void print_help(const char *argv0)
215 {
216 printf("Usage: %s [options]\n", argv0);
217 printf("Options:\n");
218 printf(" -p <port> set the TCP/IP port number to use\n");
219 printf(" -h print usage help and exit\n");
220 }
221
222 int parse_args(int argc, char **argv)
223 {
224 int i;
225
226 for(i=1; i<argc; i++) {
227 if(argv[i][0] == '-' && argv[i][2] == 0) {
228 switch(argv[i][1]) {
229 case 'p':
230 if((port = atoi(argv[++i])) == 0) {
231 fprintf(stderr, "-p must be followed by a valid port number\n");
232 return -1;
233 }
234 break;
235
236 case 'h':
237 print_help(argv[0]);
238 exit(0);
239
240 default:
241 fprintf(stderr, "unrecognized option: %s\n", argv[i]);
242 return -1;
243 }
244 } else {
245 fprintf(stderr, "unexpected argument: %s\n", argv[i]);
246 return -1;
247 }
248 }
249 return 0;
250 }