Exit before transmission if receipt file cannot be created.

If opening the receipt file fails after transmission, it's too late to
tell the user about the failure.

Reviewed-by: Gabriel F. T. Gomes <gabriel@gftg.com.br>

diff --git a/rnetclient.c b/rnetclient.c
index 5d56ac1..3561b45 100644 (file)
--- a/rnetclient.c
+++ b/rnetclient.c
@@ -72,6 +72,9 @@ struct rnetclient_args {
 
        /* Output directory to save the receipt.  */
        char *output_dir;
+
+       /* Output filename. */
+       char output_file[PATH_MAX];
 };
 
 /* Parser for command line arguments.  */
@@ -343,12 +346,10 @@ static int rnet_recv(gnutls_session_t session, struct rnet_message **message)
        return 0;
 }
 
-static void save_rec_file(char *cpf, char *buffer, int len, const struct rnetclient_args *args)
+static int open_rec_file(char *cpf, struct rnetclient_args *args)
 {
        int fd;
-       char *path, *fname, *tmp;
-       size_t fname_len;
-       ssize_t r;
+       char *path, *tmp;
 
        path = args->output_dir;
 
@@ -371,47 +372,53 @@ static void save_rec_file(char *cpf, char *buffer, int len, const struct rnetcli
                   just have to change one letter.  */
                tmp = strstr(p, ".DEC");
                tmp[1] = 'R';
-               fname_len = strlen(p) + strlen(path) + 2;
-               fname = alloca(fname_len);
-               snprintf(fname, fname_len, "%s/%s", path, p);
+               snprintf(args->output_file, PATH_MAX, "%s/%s", path, p);
                free(p);
        } else {
                /* The declaration filename does not follow the
                   convention, so we will not use it as a template.
                   We just generate a filename using "$CPF.REC".  */
-               fname_len = strlen(cpf) + strlen(path) + sizeof(".REC") + 2;
-               fname = alloca(fname_len);
-               snprintf(fname, fname_len, "%s/%s.REC", path, cpf);
+               snprintf(args->output_file, PATH_MAX, "%s/%s.REC", path, cpf);
        }
        /* Now, open the file and write.  */
-       fd = open(fname, O_CREAT | O_WRONLY | O_EXCL, S_IRUSR | S_IWUSR);
+       fd = open(args->output_file, O_CREAT | O_WRONLY | O_EXCL, S_IRUSR | S_IWUSR);
        if (fd < 0) {
-               fprintf(stderr, "Could not create receipt file \"%s\": %s\n", fname, strerror(errno));
-               return;
+               fprintf(stderr, "Could not create receipt file \"%s\": %s\n",
+                       args->output_file, strerror(errno));
        }
+       return fd;
+}
+
+static int save_rec_file(int fd, char *buffer, int len, const struct rnetclient_args *args)
+{
+       ssize_t r;
+
        do {
                r = write(fd, buffer, len);
        } while (r < 0 && errno == EAGAIN);
-       if (r != len)
-               fprintf(stderr, "Could not write to receipt file: %s", strerror(errno));
-       else
-               fprintf(stderr, "Wrote the receipt file to %s.\n", fname);
-       close(fd);
+       if (r != len) {
+               fprintf(stderr, "Could not write to receipt file: %s",
+                       strerror(errno));
+       } else {
+               fprintf(stderr, "Wrote the receipt file to %s.\n",
+                       args->output_file);
+       }
+       return r;
 }
 
-static void handle_response_text_and_file(char *cpf, struct rnet_message *message, const struct rnetclient_args *args)
+static void handle_response_text_and_file(int fd, struct rnet_message *message, const struct rnetclient_args *args)
 {
        char *value;
        int vlen;
        if (!rnet_message_parse(message, "texto", &value, &vlen))
                fprintf(stderr, "%.*s\n", vlen, value);
        if (!rnet_message_parse(message, "arquivo", &value, &vlen))
-               save_rec_file(cpf, value, vlen, args);
+               save_rec_file(fd, value, vlen, args);
 }
 
-static void handle_response_already_found(char *cpf, struct rnet_message *message, const struct rnetclient_args *args)
+static void handle_response_already_found(int fd, struct rnet_message *message, const struct rnetclient_args *args)
 {
-       handle_response_text_and_file(cpf, message, args);
+       handle_response_text_and_file(fd, message, args);
 }
 
 static void handle_response_error(struct rnet_message *message)
@@ -435,6 +442,7 @@ int main(int argc, char **argv)
        char *cpf;
        error_t err;
        char cwd[PATH_MAX];
+       int outfd;
 
        /* Parsing the command line arguments.  The argp_parse
           function calls exit() if there is some error during the
@@ -476,6 +484,12 @@ int main(int argc, char **argv)
 
        cpf = rnet_decfile_get_header_field(decfile, "cpf");
 
+       outfd = open_rec_file(cpf, &rnet_args);
+       if (outfd < 0) {
+               r = 1;
+               goto out_rec;
+       }
+
        gnutls_global_init();
 
        session_new(&session);
@@ -518,19 +532,19 @@ int main(int argc, char **argv)
        }
        switch (message->buffer[0]) {
        case 1: /* go ahead */
-               handle_response_text_and_file(cpf, message, &rnet_args);
+               handle_response_text_and_file(outfd, message, &rnet_args);
                break;
        case 3: /* error */
                handle_response_error(message);
                finish = 1;
                break;
        case 4:
-               handle_response_already_found(cpf, message, &rnet_args);
+               handle_response_already_found(outfd, message, &rnet_args);
                finish = 1;
                break;
        case 2:
        case 5:
-               handle_response_text_and_file(cpf, message, &rnet_args);
+               handle_response_text_and_file(outfd, message, &rnet_args);
                finish = 1;
                break;
        }
@@ -557,7 +571,7 @@ int main(int argc, char **argv)
        case 4:
        case 5:
        case 1:
-               handle_response_text_and_file(cpf, message, &rnet_args);
+               handle_response_text_and_file(outfd, message, &rnet_args);
                break;
        }
        
@@ -567,6 +581,8 @@ out_handshake:
        close(c);
 out_connect:
        gnutls_global_deinit();
+       close(outfd);
+out_rec:
        rnet_decfile_close(decfile);
 
        return r;