#include "malloc.h"
#include "html.h"
+#include "httpd.h"
/* --- Logic driving what the web server's responses are. --- */
+enum { /* connctx states */
+ READING_REQ_LINE,
+ READING_HEADERS,
+ DONE
+};
+
struct connctx {
const void *t;
char *data;
int datalen, datasize;
+ char *method, *url, *headers, *auth;
+ int state;
};
/*
cctx->t = t;
cctx->data = NULL;
cctx->datalen = cctx->datasize = 0;
+ cctx->state = READING_REQ_LINE;
+ cctx->method = cctx->url = cctx->headers = cctx->auth = NULL;
return cctx;
}
sfree(cctx);
}
-static char *http_error(char *code, char *errmsg, char *errtext, ...)
+static char *http_error(char *code, char *errmsg, char *extraheader,
+ char *errtext, ...)
{
return dupfmt("HTTP/1.1 %s %s\r\n"
"Date: %D\r\n"
"Server: agedu\r\n"
"Connection: close\r\n"
+ "%s"
"Content-Type: text/html; charset=US-ASCII\r\n"
"\r\n"
"<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">\r\n"
"<H1>%s %s</H1>\r\n"
"<P>%s</P>\r\n"
"</BODY></HTML>\r\n", code, errmsg,
+ extraheader ? extraheader : "",
code, errmsg, code, errmsg, errtext);
}
* allocated data which the platform code will then write to the
* socket before closing it.
*/
-char *got_data(struct connctx *ctx, char *data, int length, int magic_access)
+char *got_data(struct connctx *ctx, char *data, int length,
+ int magic_access, const char *auth_string)
{
- char *line, *p, *q, *z1, *z2, c1, c2;
+ char *line, *p, *q, *r, *z1, *z2, c1, c2;
+ int auth_provided = 0, auth_correct = 0;
unsigned long index;
char *document, *ret;
+ /*
+ * Add the data we've just received to our buffer.
+ */
if (ctx->datasize < ctx->datalen + length) {
ctx->datasize = (ctx->datalen + length) * 3 / 2 + 4096;
ctx->data = sresize(ctx->data, ctx->datasize, char);
ctx->datalen += length;
/*
- * See if we have enough of an HTTP request to work out our
- * response.
- */
- line = ctx->data;
- /*
- * RFC 2616 section 4.1: `In the interest of robustness, [...]
- * if the server is reading the protocol stream at the
- * beginning of a message and receives a CRLF first, it should
- * ignore the CRLF.'
+ * Gradually process the HTTP request as we receive it.
*/
- while (line - ctx->data < ctx->datalen &&
- (*line == '\r' || *line == '\n'))
- line++;
+ if (ctx->state == READING_REQ_LINE) {
+ /*
+ * We're waiting for the first line of the input, which
+ * contains the main HTTP request. See if we've got it
+ * yet.
+ */
- q = line;
- while (q - ctx->data < ctx->datalen && *q != '\r' && *q != '\n')
- q++;
- if (q - ctx->data >= ctx->datalen)
- return NULL; /* not got request line yet */
+ line = ctx->data;
+ /*
+ * RFC 2616 section 4.1: `In the interest of robustness,
+ * [...] if the server is reading the protocol stream at
+ * the beginning of a message and receives a CRLF first,
+ * it should ignore the CRLF.'
+ */
+ while (line - ctx->data < ctx->datalen &&
+ (*line == '\r' || *line == '\n'))
+ line++;
+ q = line;
+ while (q - ctx->data < ctx->datalen && *q != '\n')
+ q++;
+ if (q - ctx->data >= ctx->datalen)
+ return NULL; /* not got request line yet */
- /*
- * We've got the first line of the request, which is enough
- * for us to work out what to say in response and start
- * sending it. The platform side will keep reading data, but
- * it'll ignore it.
- *
- * So, zero-terminate our line and parse it.
- */
- *q = '\0';
- z1 = z2 = q;
- c1 = c2 = *q;
- p = line;
- while (*p && !isspace((unsigned char)*p)) p++;
- if (*p) {
- z1 = p++;
- c1 = *z1;
- *z1 = '\0';
+ /*
+ * We've got the first line of the request. Zero-terminate
+ * and parse it into method, URL and optional HTTP
+ * version.
+ */
+ *q = '\0';
+ ctx->headers = q+1;
+ if (q > line && q[-1] == '\r')
+ *--q = '\0';
+ z1 = z2 = q;
+ c1 = c2 = *q;
+ p = line;
+ while (*p && !isspace((unsigned char)*p)) p++;
+ if (*p) {
+ z1 = p++;
+ c1 = *z1;
+ *z1 = '\0';
+ }
+ while (*p && isspace((unsigned char)*p)) p++;
+ q = p;
+ while (*q && !isspace((unsigned char)*q)) q++;
+ z2 = q++;
+ c2 = *z2;
+ *z2 = '\0';
+ while (*q && isspace((unsigned char)*q)) q++;
+
+ /*
+ * Now `line' points at the method name; p points at the
+ * URL, if any; q points at the HTTP version, if any.
+ */
+
+ /*
+ * There should _be_ a URL, on any request type at all.
+ */
+ if (!*p) {
+ char *ret, *text;
+ /* Restore the request to the way we received it. */
+ *z2 = c2;
+ *z1 = c1;
+ text = dupfmt("<code>agedu</code> received the HTTP request"
+ " \"<code>%h</code>\", which contains no URL.",
+ line);
+ ret = http_error("400", "Bad request", NULL, text);
+ sfree(text);
+ return ret;
+ }
+
+ ctx->method = line;
+ ctx->url = p;
+
+ /*
+ * If there was an HTTP version, we might need to see
+ * headers. Otherwise, the request is done.
+ */
+ if (*q) {
+ ctx->state = READING_HEADERS;
+ } else {
+ ctx->state = DONE;
+ }
}
- while (*p && isspace((unsigned char)*p)) p++;
- q = p;
- while (*q && !isspace((unsigned char)*q)) q++;
- z2 = q;
- c2 = *z2;
- *z2 = '\0';
- /*
- * Now `line' points at the method name; p points at the URL,
- * if any.
- */
-
- /*
- * There should _be_ a URL, on any request type at all.
- */
- if (!*p) {
- char *ret, *text;
- *z2 = c2;
- *z1 = c1;
- text = dupfmt("<code>agedu</code> received the HTTP request"
- " \"<code>%s</code>\", which contains no URL.",
- line);
- ret = http_error("400", "Bad request", text);
- sfree(text);
- return ret;
+ if (ctx->state == READING_HEADERS) {
+ /*
+ * While we're receiving the HTTP request headers, all we
+ * do is to keep scanning to see if we find two newlines
+ * next to each other.
+ */
+ q = ctx->data + ctx->datalen;
+ for (p = ctx->headers; p < q; p++) {
+ if (*p == '\n' &&
+ ((p+1 < q && p[1] == '\n') ||
+ (p+2 < q && p[1] == '\r' && p[2] == '\n'))) {
+ p[1] = '\0';
+ ctx->state = DONE;
+ break;
+ }
+ }
}
- if (!magic_access) {
- ret = http_error("403", "Forbidden",
- "This is a restricted-access set of pages.");
- } else {
- p += strspn(p, "/?");
- index = strtoul(p, NULL, 10);
- document = html_query(ctx->t, index, "%lu");
- if (document) {
- ret = http_success("text/html", 1, document);
- sfree(document);
+ if (ctx->state == DONE) {
+ /*
+ * Now we have the entire HTTP request. Decide what to do
+ * with it.
+ */
+ if (auth_string) {
+ /*
+ * Search the request headers for Authorization.
+ */
+ q = ctx->data + ctx->datalen;
+ for (p = ctx->headers; p < q; p++) {
+ const char *hdr = "Authorization:";
+ int i;
+ for (i = 0; hdr[i]; i++) {
+ if (p >= q || tolower((unsigned char)*p) !=
+ tolower((unsigned char)hdr[i]))
+ break;
+ p++;
+ }
+ if (!hdr[i])
+ break; /* found our header */
+ p = memchr(p, '\n', q - p);
+ if (!p)
+ p = q;
+ }
+ if (p < q) {
+ auth_provided = 1;
+ while (p < q && isspace((unsigned char)*p))
+ p++;
+ r = p;
+ while (p < q && !isspace((unsigned char)*p))
+ p++;
+ if (p < q) {
+ *p++ = '\0';
+ if (!strcasecmp(r, "Basic")) {
+ while (p < q && isspace((unsigned char)*p))
+ p++;
+ r = p;
+ while (p < q && !isspace((unsigned char)*p))
+ p++;
+ if (p < q) {
+ *p++ = '\0';
+ if (!strcmp(r, auth_string))
+ auth_correct = 1;
+ }
+ }
+ }
+ }
+ }
+
+ if (!magic_access && !auth_correct) {
+ if (auth_string && !auth_provided) {
+ ret = http_error("401", "Unauthorized",
+ "WWW-Authenticate: Basic realm=\"agedu\"\r\n",
+ "Please authenticate to view these pages.");
+ } else {
+ ret = http_error("403", "Forbidden", NULL,
+ "This is a restricted-access set of pages.");
+ }
} else {
- ret = http_error("404", "Not Found",
- "Pathname index out of range.");
+ p = ctx->url;
+ p += strspn(p, "/?");
+ index = strtoul(p, NULL, 10);
+ document = html_query(ctx->t, index, "%lu");
+ if (document) {
+ ret = http_success("text/html", 1, document);
+ sfree(document);
+ } else {
+ ret = http_error("404", "Not Found", NULL,
+ "Pathname index out of range.");
+ }
}
- }
- return ret;
+ return ret;
+ } else
+ return NULL;
}
/* --- Platform support for running a web server. --- */
return ret;
}
-void check_magic_access(struct fd *fd)
+int check_owning_uid(int fd, int flip)
{
struct sockaddr_in sock, peer;
socklen_t addrlen;
FILE *fp;
addrlen = sizeof(sock);
- if (getsockname(fd->fd, (struct sockaddr *)&sock, &addrlen)) {
+ if (getsockname(fd, (struct sockaddr *)&sock, &addrlen)) {
fprintf(stderr, "getsockname: %s\n", strerror(errno));
exit(1);
}
addrlen = sizeof(peer);
- if (getpeername(fd->fd, (struct sockaddr *)&peer, &addrlen)) {
- fprintf(stderr, "getpeername: %s\n", strerror(errno));
- exit(1);
+ if (getpeername(fd, (struct sockaddr *)&peer, &addrlen)) {
+ if (errno == ENOTCONN) {
+ peer.sin_addr.s_addr = htonl(0);
+ peer.sin_port = htons(0);
+ } else {
+ fprintf(stderr, "getpeername: %s\n", strerror(errno));
+ exit(1);
+ }
+ }
+
+ if (flip) {
+ struct sockaddr_in tmp = sock;
+ sock = peer;
+ peer = tmp;
}
sprintf(matchbuf, "%08X:%04X %08X:%04X",
while (fgets(linebuf, sizeof(linebuf), fp)) {
if (strlen(linebuf) >= 75 &&
!strncmp(linebuf+6, matchbuf, strlen(matchbuf))) {
- int uid = atoi(linebuf + 75);
- if (uid == getuid())
- fd->magic_access = 1;
+ return atoi(linebuf + 75);
}
}
}
+
+ return -1;
+}
+
+void check_magic_access(struct fd *fd)
+{
+ if (check_owning_uid(fd->fd, 0) == getuid())
+ fd->magic_access = 1;
}
-void run_httpd(const void *t)
+static void base64_encode_atom(unsigned char *data, int n, char *out)
+{
+ static const char base64_chars[] =
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+ unsigned word;
+
+ word = data[0] << 16;
+ if (n > 1)
+ word |= data[1] << 8;
+ if (n > 2)
+ word |= data[2];
+ out[0] = base64_chars[(word >> 18) & 0x3F];
+ out[1] = base64_chars[(word >> 12) & 0x3F];
+ if (n > 1)
+ out[2] = base64_chars[(word >> 6) & 0x3F];
+ else
+ out[2] = '=';
+ if (n > 2)
+ out[3] = base64_chars[word & 0x3F];
+ else
+ out[3] = '=';
+}
+
+void run_httpd(const void *t, int authmask)
{
int fd;
+ int authtype;
+ char *authstring = NULL, authbuf[512];
unsigned long ipaddr;
struct fd *f;
struct sockaddr_in addr;
fprintf(stderr, "getsockname: %s\n", strerror(errno));
exit(1);
}
- printf("Server is at http://%s:%d/\n",
+ if ((authmask & HTTPD_AUTH_MAGIC) &&
+ (check_owning_uid(fd, 1) == getuid())) {
+ authtype = HTTPD_AUTH_MAGIC;
+ printf("Using Linux /proc/net magic authentication\n");
+ } else if ((authmask & HTTPD_AUTH_BASIC)) {
+ char username[128], password[128], userpass[259];
+ const char *rname;
+ unsigned char passbuf[10];
+ int i, j, k, fd;
+
+ authtype = HTTPD_AUTH_BASIC;
+
+ sprintf(username, "agedu");
+ rname = "/dev/urandom";
+ fd = open(rname, O_RDONLY);
+ if (fd < 0) {
+ int err = errno;
+ rname = "/dev/random";
+ fd = open(rname, O_RDONLY);
+ if (fd < 0) {
+ int err2 = errno;
+ fprintf(stderr, "/dev/urandom: open: %s\n", strerror(err));
+ fprintf(stderr, "/dev/random: open: %s\n", strerror(err2));
+ exit(1);
+ }
+ }
+ for (i = 0; i < 10 ;) {
+ j = read(fd, passbuf + i, 10 - i);
+ if (j <= 0) {
+ fprintf(stderr, "%s: read: %s\n", rname,
+ j < 0 ? strerror(errno) : "unexpected EOF");
+ exit(1);
+ }
+ i += j;
+ }
+ close(fd);
+ for (i = 0; i < 16; i++) {
+ /* 32 characters out of the 36 alphanumerics gives me the
+ * latitude to discard i,l,o for being too numeric-looking,
+ * and w because it has two too many syllables and one too
+ * many presidential associations. */
+ static const char chars[32] = "0123456789abcdefghjkmnpqrstuvxyz";
+ int v = 0;
+
+ k = i / 8 * 5;
+ for (j = 0; j < 5; j++)
+ v |= ((passbuf[k+j] >> (i%8)) & 1) << j;
+
+ password[i] = chars[v];
+ }
+ password[i] = '\0';
+
+ printf("Using HTTP Basic authentication\nUsername: %s\nPassword: %s\n",
+ username, password);
+
+ k = sprintf(userpass, "%s:%s", username, password);
+ for (i = j = 0; i < k ;) {
+ int s = k-i < 3 ? k-i : 3;
+ base64_encode_atom((unsigned char *)(userpass+i), s, authbuf+j);
+ i += s;
+ j += 4;
+ }
+ authbuf[j] = '\0';
+ authstring = authbuf;
+ } else {
+ authtype = HTTPD_AUTH_NONE;
+ printf("Web server is unauthenticated\n");
+ }
+ printf("URL: http://%s:%d/\n",
inet_ntoa(addr.sin_addr), ntohs(addr.sin_port));
/*
f = new_fdstruct(newfd, FD_CONNECTION);
f->cctx = new_connection(t);
- check_magic_access(f);
+ if (authtype == HTTPD_AUTH_MAGIC)
+ check_magic_access(f);
}
break;
case FD_CONNECTION:
* yet, keep processing data in the
* hope of acquiring one.
*/
- fds[i].wdata = got_data(fds[i].cctx, readbuf,
- ret, fds[i].magic_access);
+ fds[i].wdata = got_data
+ (fds[i].cctx, readbuf, ret,
+ (authtype == HTTPD_AUTH_NONE ||
+ fds[i].magic_access), authstring);
if (fds[i].wdata) {
fds[i].wdatalen = strlen(fds[i].wdata);
fds[i].wdatapos = 0;
~mdw / sgt / agedu / commitdiff