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>

1 files changed, 223 insertions, 42 deletions

diff --git a/tools/iio/iio_utils.c b/tools/iio/iio_utils.c
index f0896f46847f..e1828d0d8a38 100644
--- 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;