diff options
Diffstat (limited to 'libs/libevent/docs/sample/http-server.c')
| -rw-r--r-- | libs/libevent/docs/sample/http-server.c | 418 |
1 files changed, 418 insertions, 0 deletions
diff --git a/libs/libevent/docs/sample/http-server.c b/libs/libevent/docs/sample/http-server.c new file mode 100644 index 0000000000..cbb9c914dd --- /dev/null +++ b/libs/libevent/docs/sample/http-server.c @@ -0,0 +1,418 @@ +/* + A trivial static http webserver using Libevent's evhttp. + + This is not the best code in the world, and it does some fairly stupid stuff + that you would never want to do in a production webserver. Caveat hackor! + + */ + +/* Compatibility for possible missing IPv6 declarations */ +#include "../util-internal.h" + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include <sys/types.h> +#include <sys/stat.h> + +#ifdef _WIN32 +#include <winsock2.h> +#include <ws2tcpip.h> +#include <windows.h> +#include <io.h> +#include <fcntl.h> +#ifndef S_ISDIR +#define S_ISDIR(x) (((x) & S_IFMT) == S_IFDIR) +#endif +#else +#include <sys/stat.h> +#include <sys/socket.h> +#include <signal.h> +#include <fcntl.h> +#include <unistd.h> +#include <dirent.h> +#endif + +#include <event2/event.h> +#include <event2/http.h> +#include <event2/buffer.h> +#include <event2/util.h> +#include <event2/keyvalq_struct.h> + +#ifdef EVENT__HAVE_NETINET_IN_H +#include <netinet/in.h> +# ifdef _XOPEN_SOURCE_EXTENDED +# include <arpa/inet.h> +# endif +#endif + +#ifdef _WIN32 +#ifndef stat +#define stat _stat +#endif +#ifndef fstat +#define fstat _fstat +#endif +#ifndef open +#define open _open +#endif +#ifndef close +#define close _close +#endif +#ifndef O_RDONLY +#define O_RDONLY _O_RDONLY +#endif +#endif + +char uri_root[512]; + +static const struct table_entry { + const char *extension; + const char *content_type; +} content_type_table[] = { + { "txt", "text/plain" }, + { "c", "text/plain" }, + { "h", "text/plain" }, + { "html", "text/html" }, + { "htm", "text/htm" }, + { "css", "text/css" }, + { "gif", "image/gif" }, + { "jpg", "image/jpeg" }, + { "jpeg", "image/jpeg" }, + { "png", "image/png" }, + { "pdf", "application/pdf" }, + { "ps", "application/postsript" }, + { NULL, NULL }, +}; + +/* Try to guess a good content-type for 'path' */ +static const char * +guess_content_type(const char *path) +{ + const char *last_period, *extension; + const struct table_entry *ent; + last_period = strrchr(path, '.'); + if (!last_period || strchr(last_period, '/')) + goto not_found; /* no exension */ + extension = last_period + 1; + for (ent = &content_type_table[0]; ent->extension; ++ent) { + if (!evutil_ascii_strcasecmp(ent->extension, extension)) + return ent->content_type; + } + +not_found: + return "application/misc"; +} + +/* Callback used for the /dump URI, and for every non-GET request: + * dumps all information to stdout and gives back a trivial 200 ok */ +static void +dump_request_cb(struct evhttp_request *req, void *arg) +{ + const char *cmdtype; + struct evkeyvalq *headers; + struct evkeyval *header; + struct evbuffer *buf; + + switch (evhttp_request_get_command(req)) { + case EVHTTP_REQ_GET: cmdtype = "GET"; break; + case EVHTTP_REQ_POST: cmdtype = "POST"; break; + case EVHTTP_REQ_HEAD: cmdtype = "HEAD"; break; + case EVHTTP_REQ_PUT: cmdtype = "PUT"; break; + case EVHTTP_REQ_DELETE: cmdtype = "DELETE"; break; + case EVHTTP_REQ_OPTIONS: cmdtype = "OPTIONS"; break; + case EVHTTP_REQ_TRACE: cmdtype = "TRACE"; break; + case EVHTTP_REQ_CONNECT: cmdtype = "CONNECT"; break; + case EVHTTP_REQ_PATCH: cmdtype = "PATCH"; break; + default: cmdtype = "unknown"; break; + } + + printf("Received a %s request for %s\nHeaders:\n", + cmdtype, evhttp_request_get_uri(req)); + + headers = evhttp_request_get_input_headers(req); + for (header = headers->tqh_first; header; + header = header->next.tqe_next) { + printf(" %s: %s\n", header->key, header->value); + } + + buf = evhttp_request_get_input_buffer(req); + puts("Input data: <<<"); + while (evbuffer_get_length(buf)) { + int n; + char cbuf[128]; + n = evbuffer_remove(buf, cbuf, sizeof(cbuf)); + if (n > 0) + (void) fwrite(cbuf, 1, n, stdout); + } + puts(">>>"); + + evhttp_send_reply(req, 200, "OK", NULL); +} + +/* This callback gets invoked when we get any http request that doesn't match + * any other callback. Like any evhttp server callback, it has a simple job: + * it must eventually call evhttp_send_error() or evhttp_send_reply(). + */ +static void +send_document_cb(struct evhttp_request *req, void *arg) +{ + struct evbuffer *evb = NULL; + const char *docroot = arg; + const char *uri = evhttp_request_get_uri(req); + struct evhttp_uri *decoded = NULL; + const char *path; + char *decoded_path; + char *whole_path = NULL; + size_t len; + int fd = -1; + struct stat st; + + if (evhttp_request_get_command(req) != EVHTTP_REQ_GET) { + dump_request_cb(req, arg); + return; + } + + printf("Got a GET request for <%s>\n", uri); + + /* Decode the URI */ + decoded = evhttp_uri_parse(uri); + if (!decoded) { + printf("It's not a good URI. Sending BADREQUEST\n"); + evhttp_send_error(req, HTTP_BADREQUEST, 0); + return; + } + + /* Let's see what path the user asked for. */ + path = evhttp_uri_get_path(decoded); + if (!path) path = "/"; + + /* We need to decode it, to see what path the user really wanted. */ + decoded_path = evhttp_uridecode(path, 0, NULL); + if (decoded_path == NULL) + goto err; + /* Don't allow any ".."s in the path, to avoid exposing stuff outside + * of the docroot. This test is both overzealous and underzealous: + * it forbids aceptable paths like "/this/one..here", but it doesn't + * do anything to prevent symlink following." */ + if (strstr(decoded_path, "..")) + goto err; + + len = strlen(decoded_path)+strlen(docroot)+2; + if (!(whole_path = malloc(len))) { + perror("malloc"); + goto err; + } + evutil_snprintf(whole_path, len, "%s/%s", docroot, decoded_path); + + if (stat(whole_path, &st)<0) { + goto err; + } + + /* This holds the content we're sending. */ + evb = evbuffer_new(); + + if (S_ISDIR(st.st_mode)) { + /* If it's a directory, read the comments and make a little + * index page */ +#ifdef _WIN32 + HANDLE d; + WIN32_FIND_DATAA ent; + char *pattern; + size_t dirlen; +#else + DIR *d; + struct dirent *ent; +#endif + const char *trailing_slash = ""; + + if (!strlen(path) || path[strlen(path)-1] != '/') + trailing_slash = "/"; + +#ifdef _WIN32 + dirlen = strlen(whole_path); + pattern = malloc(dirlen+3); + memcpy(pattern, whole_path, dirlen); + pattern[dirlen] = '\\'; + pattern[dirlen+1] = '*'; + pattern[dirlen+2] = '\0'; + d = FindFirstFileA(pattern, &ent); + free(pattern); + if (d == INVALID_HANDLE_VALUE) + goto err; +#else + if (!(d = opendir(whole_path))) + goto err; +#endif + + evbuffer_add_printf(evb, + "<!DOCTYPE html>\n" + "<html>\n <head>\n" + " <meta charset='utf-8'>\n" + " <title>%s</title>\n" + " <base href='%s%s'>\n" + " </head>\n" + " <body>\n" + " <h1>%s</h1>\n" + " <ul>\n", + decoded_path, /* XXX html-escape this. */ + path, /* XXX html-escape this? */ + trailing_slash, + decoded_path /* XXX html-escape this */); +#ifdef _WIN32 + do { + const char *name = ent.cFileName; +#else + while ((ent = readdir(d))) { + const char *name = ent->d_name; +#endif + evbuffer_add_printf(evb, + " <li><a href=\"%s\">%s</a>\n", + name, name);/* XXX escape this */ +#ifdef _WIN32 + } while (FindNextFileA(d, &ent)); +#else + } +#endif + evbuffer_add_printf(evb, "</ul></body></html>\n"); +#ifdef _WIN32 + FindClose(d); +#else + closedir(d); +#endif + evhttp_add_header(evhttp_request_get_output_headers(req), + "Content-Type", "text/html"); + } else { + /* Otherwise it's a file; add it to the buffer to get + * sent via sendfile */ + const char *type = guess_content_type(decoded_path); + if ((fd = open(whole_path, O_RDONLY)) < 0) { + perror("open"); + goto err; + } + + if (fstat(fd, &st)<0) { + /* Make sure the length still matches, now that we + * opened the file :/ */ + perror("fstat"); + goto err; + } + evhttp_add_header(evhttp_request_get_output_headers(req), + "Content-Type", type); + evbuffer_add_file(evb, fd, 0, st.st_size); + } + + evhttp_send_reply(req, 200, "OK", evb); + goto done; +err: + evhttp_send_error(req, 404, "Document was not found"); + if (fd>=0) + close(fd); +done: + if (decoded) + evhttp_uri_free(decoded); + if (decoded_path) + free(decoded_path); + if (whole_path) + free(whole_path); + if (evb) + evbuffer_free(evb); +} + +static void +syntax(void) +{ + fprintf(stdout, "Syntax: http-server <docroot>\n"); +} + +int +main(int argc, char **argv) +{ + struct event_base *base; + struct evhttp *http; + struct evhttp_bound_socket *handle; + + unsigned short port = 0; +#ifdef _WIN32 + WSADATA WSAData; + WSAStartup(0x101, &WSAData); +#else + if (signal(SIGPIPE, SIG_IGN) == SIG_ERR) + return (1); +#endif + if (argc < 2) { + syntax(); + return 1; + } + + base = event_base_new(); + if (!base) { + fprintf(stderr, "Couldn't create an event_base: exiting\n"); + return 1; + } + + /* Create a new evhttp object to handle requests. */ + http = evhttp_new(base); + if (!http) { + fprintf(stderr, "couldn't create evhttp. Exiting.\n"); + return 1; + } + + /* The /dump URI will dump all requests to stdout and say 200 ok. */ + evhttp_set_cb(http, "/dump", dump_request_cb, NULL); + + /* We want to accept arbitrary requests, so we need to set a "generic" + * cb. We can also add callbacks for specific paths. */ + evhttp_set_gencb(http, send_document_cb, argv[1]); + + /* Now we tell the evhttp what port to listen on */ + handle = evhttp_bind_socket_with_handle(http, "0.0.0.0", port); + if (!handle) { + fprintf(stderr, "couldn't bind to port %d. Exiting.\n", + (int)port); + return 1; + } + + { + /* Extract and display the address we're listening on. */ + struct sockaddr_storage ss; + evutil_socket_t fd; + ev_socklen_t socklen = sizeof(ss); + char addrbuf[128]; + void *inaddr; + const char *addr; + int got_port = -1; + fd = evhttp_bound_socket_get_fd(handle); + memset(&ss, 0, sizeof(ss)); + if (getsockname(fd, (struct sockaddr *)&ss, &socklen)) { + perror("getsockname() failed"); + return 1; + } + if (ss.ss_family == AF_INET) { + got_port = ntohs(((struct sockaddr_in*)&ss)->sin_port); + inaddr = &((struct sockaddr_in*)&ss)->sin_addr; + } else if (ss.ss_family == AF_INET6) { + got_port = ntohs(((struct sockaddr_in6*)&ss)->sin6_port); + inaddr = &((struct sockaddr_in6*)&ss)->sin6_addr; + } else { + fprintf(stderr, "Weird address family %d\n", + ss.ss_family); + return 1; + } + addr = evutil_inet_ntop(ss.ss_family, inaddr, addrbuf, + sizeof(addrbuf)); + if (addr) { + printf("Listening on %s:%d\n", addr, got_port); + evutil_snprintf(uri_root, sizeof(uri_root), + "http://%s:%d",addr,got_port); + } else { + fprintf(stderr, "evutil_inet_ntop failed\n"); + return 1; + } + } + + event_base_dispatch(base); + + return 0; +} |