tools:iio:iio_utils: add error handling

Add error handling to calls which can indicate a major problem by
returning an error code.
This also sets ret to -ENOENT in iioutils_get_type() and
iioutils_get_param_float() to indicate if no matching directory entry was
found.

Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/tools/iio/iio_utils.c b/tools/iio/iio_utils.c
index f0896f4..e1828d0 100644 (file)
--- a/tools/iio/iio_utils.c
+++ b/tools/iio/iio_utils.c
@@ -50,6 +50,10 @@ int iioutils_break_up_name(const char *full_name,
                return -ENOMEM;
 
        working = strtok(current, "_\0");
+       if (!working) {
+               free(current);
+               return -EINVAL;
+       }
 
        w = working;
        r = working;
@@ -117,6 +121,7 @@ int iioutils_get_type(unsigned *is_signed,
                ret = -errno;
                goto error_free_builtname_generic;
        }
+       ret = -ENOENT;
        while (ent = readdir(dp), ent != NULL)
                /*
                 * Do we allow devices to override a generic name with
@@ -162,7 +167,12 @@ int iioutils_get_type(unsigned *is_signed,
                                *is_signed = 1;
                        else
                                *is_signed = 0;
-                       fclose(sysfsfp);
+                       if (fclose(sysfsfp)) {
+                               ret = -errno;
+                               printf("Failed to close %s\n", filename);
+                               goto error_free_filename;
+                       }
+
                        free(filename);
 
                        filename = 0;
@@ -170,12 +180,16 @@ int iioutils_get_type(unsigned *is_signed,
                }
 error_close_sysfsfp:
        if (sysfsfp)
-               fclose(sysfsfp);
+               if (fclose(sysfsfp))
+                       perror("iioutils_get_type(): Failed to close file");
+
 error_free_filename:
        if (filename)
                free(filename);
 error_closedir:
-       closedir(dp);
+       if (closedir(dp) == -1)
+               perror("iioutils_get_type(): Failed to close directory");
+
 error_free_builtname_generic:
        free(builtname_generic);
 error_free_builtname:
@@ -215,6 +229,7 @@ int iioutils_get_param_float(float *output,
                ret = -errno;
                goto error_free_builtname_generic;
        }
+       ret = -ENOENT;
        while (ent = readdir(dp), ent != NULL)
                if ((strcmp(builtname, ent->d_name) == 0) ||
                    (strcmp(builtname_generic, ent->d_name) == 0)) {
@@ -229,14 +244,19 @@ int iioutils_get_param_float(float *output,
                                ret = -errno;
                                goto error_free_filename;
                        }
-                       fscanf(sysfsfp, "%f", output);
+                       errno = 0;
+                       if (fscanf(sysfsfp, "%f", output) != 1)
+                               ret = errno ? -errno : -ENODATA;
+
                        break;
                }
 error_free_filename:
        if (filename)
                free(filename);
 error_closedir:
-       closedir(dp);
+       if (closedir(dp) == -1)
+               perror("iioutils_get_param_float(): Failed to close directory");
+
 error_free_builtname_generic:
        free(builtname_generic);
 error_free_builtname:
@@ -310,10 +330,24 @@ int build_channel_array(const char *device_dir,
                                free(filename);
                                goto error_close_dir;
                        }
-                       fscanf(sysfsfp, "%i", &ret);
+                       errno = 0;
+                       if (fscanf(sysfsfp, "%i", &ret) != 1) {
+                               ret = errno ? -errno : -ENODATA;
+                               if (fclose(sysfsfp))
+                                       perror("build_channel_array(): Failed to close file");
+
+                               free(filename);
+                               goto error_close_dir;
+                       }
+
                        if (ret == 1)
                                (*counter)++;
-                       fclose(sysfsfp);
+                       if (fclose(sysfsfp)) {
+                               ret = -errno;
+                               free(filename);
+                               goto error_close_dir;
+                       }
+
                        free(filename);
                }
        *ci_array = malloc(sizeof(**ci_array) * (*counter));
@@ -344,8 +378,20 @@ int build_channel_array(const char *device_dir,
                                count--;
                                goto error_cleanup_array;
                        }
-                       fscanf(sysfsfp, "%i", &current_enabled);
-                       fclose(sysfsfp);
+                       errno = 0;
+                       if (fscanf(sysfsfp, "%i", &current_enabled) != 1) {
+                               ret = errno ? -errno : -ENODATA;
+                               free(filename);
+                               count--;
+                               goto error_cleanup_array;
+                       }
+
+                       if (fclose(sysfsfp)) {
+                               ret = -errno;
+                               free(filename);
+                               count--;
+                               goto error_cleanup_array;
+                       }
 
                        if (!current_enabled) {
                                free(filename);
@@ -383,8 +429,29 @@ int build_channel_array(const char *device_dir,
                                goto error_cleanup_array;
                        }
                        sysfsfp = fopen(filename, "r");
-                       fscanf(sysfsfp, "%u", &current->index);
-                       fclose(sysfsfp);
+                       if (sysfsfp == NULL) {
+                               ret = -errno;
+                               printf("failed to open %s\n", filename);
+                               free(filename);
+                               goto error_cleanup_array;
+                       }
+
+                       errno = 0;
+                       if (fscanf(sysfsfp, "%u", &current->index) != 1) {
+                               ret = errno ? -errno : -ENODATA;
+                               if (fclose(sysfsfp))
+                                       perror("build_channel_array(): Failed to close file");
+
+                               free(filename);
+                               goto error_cleanup_array;
+                       }
+
+                       if (fclose(sysfsfp)) {
+                               ret = -errno;
+                               free(filename);
+                               goto error_cleanup_array;
+                       }
+
                        free(filename);
                        /* Find the scale */
                        ret = iioutils_get_param_float(&current->scale,
@@ -410,10 +477,16 @@ int build_channel_array(const char *device_dir,
                                                device_dir,
                                                current->name,
                                                current->generic_name);
+                       if (ret < 0)
+                               goto error_cleanup_array;
                }
        }
 
-       closedir(dp);
+       if (closedir(dp) == -1) {
+               ret = -errno;
+               goto error_cleanup_array;
+       }
+
        free(scan_el_dir);
        /* reorder so that the array is in index order */
        bsort_channel_array_by_index(ci_array, *counter);
@@ -427,7 +500,10 @@ error_cleanup_array:
        }
        free(*ci_array);
 error_close_dir:
-       closedir(dp);
+       if (dp)
+               if (closedir(dp) == -1)
+                       perror("build_channel_array(): Failed to close dir");
+
 error_free_name:
        free(scan_el_dir);
 error_ret:
@@ -496,29 +572,45 @@ int find_type_by_name(const char *name, const char *type)
                                                + numstrlen
                                                + 6);
                                if (filename == NULL) {
-                                       closedir(dp);
-                                       return -ENOMEM;
+                                       ret = -ENOMEM;
+                                       goto error_close_dir;
+                               }
+
+                               ret = sprintf(filename, "%s%s%d/name", iio_dir,
+                                             type, number);
+                               if (ret < 0) {
+                                       free(filename);
+                                       goto error_close_dir;
                                }
-                               sprintf(filename, "%s%s%d/name",
-                                       iio_dir,
-                                       type,
-                                       number);
+
                                nameFile = fopen(filename, "r");
                                if (!nameFile) {
                                        free(filename);
                                        continue;
                                }
                                free(filename);
-                               fscanf(nameFile, "%s", thisname);
-                               fclose(nameFile);
+                               errno = 0;
+                               if (fscanf(nameFile, "%s", thisname) != 1) {
+                                       ret = errno ? -errno : -ENODATA;
+                                       goto error_close_dir;
+                               }
+
+                               if (fclose(nameFile)) {
+                                       ret = -errno;
+                                       goto error_close_dir;
+                               }
+
                                if (strcmp(name, thisname) == 0) {
-                                       closedir(dp);
+                                       if (closedir(dp) == -1)
+                                               return -errno;
                                        return number;
                                }
                        }
                }
        }
-       closedir(dp);
+       if (closedir(dp) == -1)
+               return -errno;
+
        return -ENODEV;
 
 error_close_dir:
@@ -536,15 +628,29 @@ static int _write_sysfs_int(char *filename, char *basedir, int val, int verify)
 
        if (temp == NULL)
                return -ENOMEM;
-       sprintf(temp, "%s/%s", basedir, filename);
+       ret = sprintf(temp, "%s/%s", basedir, filename);
+       if (ret < 0)
+               goto error_free;
+
        sysfsfp = fopen(temp, "w");
        if (sysfsfp == NULL) {
                ret = -errno;
                printf("failed to open %s\n", temp);
                goto error_free;
        }
-       fprintf(sysfsfp, "%d", val);
-       fclose(sysfsfp);
+       ret = fprintf(sysfsfp, "%d", val);
+       if (ret < 0) {
+               if (fclose(sysfsfp))
+                       perror("_write_sysfs_int(): Failed to close dir");
+
+               goto error_free;
+       }
+
+       if (fclose(sysfsfp)) {
+               ret = -errno;
+               goto error_free;
+       }
+
        if (verify) {
                sysfsfp = fopen(temp, "r");
                if (sysfsfp == NULL) {
@@ -552,8 +658,19 @@ static int _write_sysfs_int(char *filename, char *basedir, int val, int verify)
                        printf("failed to open %s\n", temp);
                        goto error_free;
                }
-               fscanf(sysfsfp, "%d", &test);
-               fclose(sysfsfp);
+               if (fscanf(sysfsfp, "%d", &test) != 1) {
+                       ret = errno ? -errno : -ENODATA;
+                       if (fclose(sysfsfp))
+                               perror("_write_sysfs_int(): Failed to close dir");
+
+                       goto error_free;
+               }
+
+               if (fclose(sysfsfp)) {
+                       ret = -errno;
+                       goto error_free;
+               }
+
                if (test != val) {
                        printf("Possible failure in int write %d to %s%s\n",
                                val,
@@ -588,15 +705,29 @@ static int _write_sysfs_string(char *filename, char *basedir, char *val,
                printf("Memory allocation failed\n");
                return -ENOMEM;
        }
-       sprintf(temp, "%s/%s", basedir, filename);
+       ret = sprintf(temp, "%s/%s", basedir, filename);
+       if (ret < 0)
+               goto error_free;
+
        sysfsfp = fopen(temp, "w");
        if (sysfsfp == NULL) {
                ret = -errno;
                printf("Could not open %s\n", temp);
                goto error_free;
        }
-       fprintf(sysfsfp, "%s", val);
-       fclose(sysfsfp);
+       ret = fprintf(sysfsfp, "%s", val);
+       if (ret < 0) {
+               if (fclose(sysfsfp))
+                       perror("_write_sysfs_string(): Failed to close dir");
+
+               goto error_free;
+       }
+
+       if (fclose(sysfsfp)) {
+               ret = -errno;
+               goto error_free;
+       }
+
        if (verify) {
                sysfsfp = fopen(temp, "r");
                if (sysfsfp == NULL) {
@@ -604,8 +735,19 @@ static int _write_sysfs_string(char *filename, char *basedir, char *val,
                        printf("could not open file to verify\n");
                        goto error_free;
                }
-               fscanf(sysfsfp, "%s", temp);
-               fclose(sysfsfp);
+               if (fscanf(sysfsfp, "%s", temp) != 1) {
+                       ret = errno ? -errno : -ENODATA;
+                       if (fclose(sysfsfp))
+                               perror("_write_sysfs_string(): Failed to close dir");
+
+                       goto error_free;
+               }
+
+               if (fclose(sysfsfp)) {
+                       ret = -errno;
+                       goto error_free;
+               }
+
                if (strcmp(temp, val) != 0) {
                        printf("Possible failure in string write of %s "
                                "Should be %s "
@@ -649,14 +791,27 @@ int read_sysfs_posint(char *filename, char *basedir)
                printf("Memory allocation failed");
                return -ENOMEM;
        }
-       sprintf(temp, "%s/%s", basedir, filename);
+       ret = sprintf(temp, "%s/%s", basedir, filename);
+       if (ret < 0)
+               goto error_free;
+
        sysfsfp = fopen(temp, "r");
        if (sysfsfp == NULL) {
                ret = -errno;
                goto error_free;
        }
-       fscanf(sysfsfp, "%d\n", &ret);
-       fclose(sysfsfp);
+       errno = 0;
+       if (fscanf(sysfsfp, "%d\n", &ret) != 1) {
+               ret = errno ? -errno : -ENODATA;
+               if (fclose(sysfsfp))
+                       perror("read_sysfs_posint(): Failed to close dir");
+
+               goto error_free;
+       }
+
+       if (fclose(sysfsfp))
+               ret = -errno;
+
 error_free:
        free(temp);
        return ret;
@@ -672,14 +827,27 @@ int read_sysfs_float(char *filename, char *basedir, float *val)
                printf("Memory allocation failed");
                return -ENOMEM;
        }
-       sprintf(temp, "%s/%s", basedir, filename);
+       ret = sprintf(temp, "%s/%s", basedir, filename);
+       if (ret < 0)
+               goto error_free;
+
        sysfsfp = fopen(temp, "r");
        if (sysfsfp == NULL) {
                ret = -errno;
                goto error_free;
        }
-       fscanf(sysfsfp, "%f\n", val);
-       fclose(sysfsfp);
+       errno = 0;
+       if (fscanf(sysfsfp, "%f\n", val) != 1) {
+               ret = errno ? -errno : -ENODATA;
+               if (fclose(sysfsfp))
+                       perror("read_sysfs_float(): Failed to close dir");
+
+               goto error_free;
+       }
+
+       if (fclose(sysfsfp))
+               ret = -errno;
+
 error_free:
        free(temp);
        return ret;
@@ -695,14 +863,27 @@ int read_sysfs_string(const char *filename, const char *basedir, char *str)
                printf("Memory allocation failed");
                return -ENOMEM;
        }
-       sprintf(temp, "%s/%s", basedir, filename);
+       ret = sprintf(temp, "%s/%s", basedir, filename);
+       if (ret < 0)
+               goto error_free;
+
        sysfsfp = fopen(temp, "r");
        if (sysfsfp == NULL) {
                ret = -errno;
                goto error_free;
        }
-       fscanf(sysfsfp, "%s\n", str);
-       fclose(sysfsfp);
+       errno = 0;
+       if (fscanf(sysfsfp, "%s\n", str) != 1) {
+               ret = errno ? -errno : -ENODATA;
+               if (fclose(sysfsfp))
+                       perror("read_sysfs_string(): Failed to close dir");
+
+               goto error_free;
+       }
+
+       if (fclose(sysfsfp))
+               ret = -errno;
+
 error_free:
        free(temp);
        return ret;