hfingerd

commit 921d563a92567c81a7f8597c140afbe9adaf17b7
parent 43967ebf07c808f9a565cf8ab96b73aa49e47577
Author: hhvn <dev@hhvn.uk>
Date:   Sat,  5 Jun 2021 19:56:24 +0100

main.c: get raw .plan files

Diffstat:
M
main.c
 | 
78
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------------

1 file changed, 65 insertions(+), 13 deletions(-)
diff --git a/main.c b/main.c
@@ -16,15 +16,16 @@
 #define EXIT_USAGE	2
 #define CQUEUE		255
 
-/* strings for getaddrinfo() */
-#define HOST_DFLT	"localhost"
-#define PORT_DFLT	"79"
+/* defaults, must be strings to replace args */
+char *host = "localhost",
+     *port = "79",
+     *planfile = ".plan";
 
 char *argv0;
 
 void
 usage(void) {
-	printf("usage: %s [-h host] [-p port]\n", basename(argv0));
+	printf("usage: %s [-h host] [-p port] [-f planfile]\n", basename(argv0));
 	exit(EXIT_USAGE);
 }
 
@@ -111,8 +112,60 @@ get_userlist(int fd) {
 
 void
 get_plan(int fd, char *user) {
-	/* TODO */
-	return;
+	struct passwd *udata;
+	char path[1024];
+	char buf[4096];
+	int serrno;
+	FILE *plan;
+
+	errno = 0;
+	if ((udata = getpwnam(user)) == NULL) {
+		serrno = errno;
+		if (serrno == 0) {
+			dprintf(fd, "Error: no such user: %s\n", user);
+		} else {
+			dprintf(fd, "Server-side error: %s\n", strerror(serrno));
+			error("getpwnam(): %s\n", strerror(serrno));
+		}
+	}
+
+	/* drop priviledges to user */
+	if (setuid(udata->pw_uid) == -1)
+		error("setuid(): %s\n", strerror(errno));
+
+	snprintf(path, sizeof(path), "%s/%s", udata->pw_dir, planfile);
+	if (access(path, R_OK) == -1) {
+		serrno = errno;
+		switch (serrno) {
+		case ENOTDIR:
+		case ENOENT:
+			dprintf(fd, "Error: user %s does not have a %s file\n",
+					user, planfile);
+			break;
+		default:
+			dprintf(fd, "Error: cannot access user's %s file: %s\n",
+					planfile, strerror(serrno));
+			error("access(): %s: %s\n", path, strerror(serrno));
+		}
+		return;
+	}
+
+	/* TODO: check if executable
+	 *       and implement "CGI" */
+
+	if ((plan = fopen(path, "rb")) == NULL) {
+		serrno = errno;
+		dprintf(fd, "Error: cannot read user's %s file: %s\n",
+				planfile, strerror(serrno));
+		error("fopen(): %s\n", strerror(serrno));
+		return;
+	}
+
+	/* copy file to fd */
+	while (fgets(buf, sizeof(buf), plan) != NULL)
+		write(fd, buf, strlen(buf));
+		/* don't use sizeof(buf), 
+		 * or you get heartbleed for free */
 }
 
 void 
@@ -131,26 +184,25 @@ int
 main(int argc, char *argv[]) {
 	struct sockaddr *addr;
 	struct addrinfo hints;
-	char *host = NULL, 
-	     *port = NULL;
 	int sock, handle;
 	int serrno;
 	pid_t pid;
 
 	ARGBEGIN {
 	case 'h':
+		free(host);
 		host = EARGF(usage());
 		break;
 	case 'p':
+		free(port);
 		port = EARGF(usage());
 		break;
+	case 'f':
+		free(planfile);
+		planfile = EARGF(usage());
+		break;
 	} ARGEND;
 
-	if (host == NULL)
-		host = HOST_DFLT;
-	if (port == NULL)
-		port = PORT_DFLT;
-
 	memset(&hints, 0, sizeof(hints));
 	hints.ai_family = AF_INET;
 	hints.ai_flags = AI_PASSIVE;